## Package Manager Specification

Stephen P. Bennett
spb@exherbo.org
Christian Faulhammer
fauli@gentoo.org
Ciaran McCreesh
ciaran.mccreesh@googlemail.com
Ulrich Müller
ulm@gentoo.org
14th June 2026

© 2007–2026 Stephen Bennett, Ciaran McCreesh and others. Contributions are owned by their respective authors, and may have been changed substantially before inclusion.

This work is released under the Creative Commons Attribution-ShareAlike 4.0 International licence. To view a copy of this licence, visit https://creativecommons.org/licenses/by-sa/4.0/.

This version corresponds to commit 2cee9c6.

## Contents

1 Introduction
1.1 Aims and motivation
1.2 Rationale
1.3 Reporting issues
1.4 Conventions
1.5 Acknowledgements
2 EAPIs
2.1 Definition
2.2 Defined EAPIs
2.3 Reserved EAPIs
3 Names and versions
3.1 Restrictions upon names
3.1.1 Category names
3.1.2 Package names
3.1.3 Slot names
3.1.4 USE flag names
3.1.5 Repository names
3.1.6 Eclass names
3.1.7 License names
3.1.8 Keyword names
3.1.9 EAPI names
3.2 Version specifications
3.3 Version comparison
3.4 Uniqueness of versions
4 Tree layout
4.1 Top level
4.2 Category directories
4.3 Package directories
4.4 The profiles directory
4.4.1 The profiles.desc file
4.4.2 The thirdpartymirrors file
4.4.3 use.desc and related files
4.4.4 The updates directory
4.5 The licenses directory
4.6 The eclass directory
4.7 The metadata directory
4.7.1 The metadata cache
5 Profiles
5.1 General principles
5.2 Files that make up a profile
5.2.1 The parent file
5.2.2 The eapi file
5.2.3 deprecated
5.2.4 make.defaults
5.2.5 Simple line-based files
5.2.6 packages
5.2.7 packages.build
5.2.8 package.mask
5.2.9 package.provided
5.2.10 package.use
5.2.11 use.stable and package.use.stable
5.2.12 USE masking and forcing
5.3 Profile variables
5.3.1 Incremental variables
5.3.2 Specific variables and their meanings
6 Ebuild file format
7 Ebuild-defined variables
7.1 Metadata invariance
7.2 Mandatory ebuild-defined variables
7.3 Optional ebuild-defined variables
7.3.1 EAPI
7.3.2 SRC_URI
7.3.3 Keywords
7.3.4 USE state constraints
7.3.5 Properties
7.3.6 Restrict
7.3.7 RDEPEND value
7.4 Magic ebuild-defined variables
8 Dependencies
8.1 Dependency classes
8.2 Dependency specification format
8.2.1 All-of dependency specifications
8.2.2 USE-conditional dependency specifications
8.2.3 Any-of dependency specifications
8.2.4 Exactly-one-of dependency specifications
8.2.5 At-most-one-of dependency specifications
8.3 Package dependency specifications
8.3.1 Operators
8.3.2 Block operator
8.3.3 Slot dependencies
8.3.4 2-style and 4-style USE dependencies
9 Ebuild-defined functions
9.1 List of functions
9.1.1 Initial working directories
9.1.2 pkg_pretend
9.1.3 pkg_setup
9.1.4 src_unpack
9.1.5 src_prepare
9.1.6 src_configure
9.1.7 src_compile
9.1.8 src_test
9.1.9 src_install
9.1.10 pkg_preinst
9.1.11 pkg_postinst
9.1.12 pkg_prerm
9.1.13 pkg_postrm
9.1.14 pkg_config
9.1.15 pkg_info
9.1.16 pkg_nofetch
9.1.17 Default phase functions
9.2 Call order
10 Eclasses
10.1 The inherit command
10.2 Eclass-defined metadata keys
10.3 EXPORT_FUNCTIONS
11 The ebuild environment
11.1 Defined variables
11.1.1 USE and IUSE handling
11.1.2 REPLACING_VERSIONS and REPLACED_BY_VERSION
11.1.3 Offset-prefix variables
11.1.4 Path variables and trailing slash
11.2 The state of variables between functions
11.3 The state of the system between functions
12 Available commands
12.1 System commands
12.1.1 Guaranteed system commands
12.2 Commands provided by package dependencies
12.3 Ebuild-specific commands
12.3.1 Failure behaviour and related commands
12.3.2 Banned commands
12.3.3 Sandbox commands
12.3.4 Package manager query commands
12.3.5 Output commands
12.3.6 Error commands
12.3.7 Patch commands
12.3.8 Build commands
12.3.9 Installation commands
12.3.10 Commands affecting install destinations
12.3.11 Commands controlling manipulation of files in the staging area
12.3.12 USE list functions
12.3.13 Text list functions
12.3.14 Version manipulation and comparison commands
12.3.15 Misc commands
12.3.16 Debug commands
12.3.17 Reserved commands and variables
13 Merging and unmerging
13.1 Overview
13.2 Directories
13.2.1 Permissions
13.2.2 Empty directories
13.3 Regular files
13.3.1 Permissions
13.3.2 File modification times
13.3.3 Configuration file protection
13.4 Symlinks
13.4.1 Rewriting
13.5 Hard links
13.6 Other files
14 Metadata cache
14.1 Directory contents
14.2 Legacy cache file format
14.3 md5-dict cache file format
Glossary
Bibliography
A metadata.xml
B Unspecified items
C Historical curiosities
C.1 Long-obsolete features
C.2 Retroactive changes
D Feature availability by EAPI
E Differences between EAPIs
F Desk reference

## Algorithms

3.1 Version comparison top-level logic
3.2 Version comparison logic for numeric components
3.3 Version comparison logic for each numeric component after the first
3.4 Version comparison logic for letter components
3.5 Version comparison logic for suffixes
3.6 Version comparison logic for each suffix
3.7 Version comparison logic for revision components
5.1 USE masking logic
12.1 eapply logic
12.2 econf --libdir logic
12.3 einstalldocs logic
12.4 Library directory logic

## Listings

9.1 src_unpack
9.2 src_prepare, format 6
9.3 src_prepare, format 8
9.4 src_configure
9.5 src_compile, format 0
9.6 src_compile, format 1
9.7 src_compile, format 2
9.8 src_install, format 4
9.9 src_install, format 6
10.1 EXPORT_FUNCTIONS example: foo.eclass
11.1 Environment state between functions
12.1 einstall command
12.2 Create a relative path for dosym -r
C.1 If-else use blocks

## Tables

4.1 EAPIs supporting a directory for package.mask
4.2 Naming rules for files in updates directory for EAPIs
5.1 Default EAPI for profiles
5.2 EAPIs supporting directories for profile files
5.3 EAPIs supporting package.provided in profiles
5.4 EAPIs supporting use.stable and package.use.stable in profiles
5.5 Profile directory support for masking/forcing use flags in stable versions only
5.6 Profile-defined IUSE injection for EAPIs
5.7 Profile-defined unsetting of variables in EAPIs
6.1 Bash version and options
7.1 EAPIs supporting IUSE defaults
7.2 EAPIs supporting various ebuild-defined variables
7.3 EAPIs supporting SRC_URI arrows and selective URI restrictions
7.4 EAPIs with RDEPEND=DEPEND default
7.5 EAPIs supporting DEFINED_PHASES
8.1 Dependency classes required to be satisfied for a particular phase function
8.2 Summary of other interfaces related to dependency classes
8.3 Prefix values for DEPEND
8.4 EAPIs supporting additional dependency types
8.5 EAPIs supporting REQUIRED_USE ?? groups
8.6 Matching of empty dependency groups in EAPIs
8.7 Support for SLOT dependencies and sub-slots in EAPIs
8.8 EAPIs supporting USE dependencies
8.9 Exclamation mark strengths for EAPIs
9.1 Initial working directory in pkg_* phase functions for EAPIs
9.2 EAPIs with S to WORKDIR fallbacks
9.3 EAPIs supporting pkg_pretend
9.4 src_prepare support and behaviour for EAPIs
9.5 EAPIs supporting src_configure
9.6 src_compile behaviour for EAPIs
9.7 src_test behaviour for EAPIs
9.8 src_install behaviour for EAPIs
9.9 EAPIs supporting pkg_info on non-installed packages
9.10 EAPIs supporting default_ phase functions
10.1 EAPIs accumulating PROPERTIES and RESTRICT across eclasses
11.1 EAPIs with variables exported to the environment
11.2 Defined variables
11.3 EAPIs supporting various added env variables
11.4 EAPIs supporting various removed env variables
11.5 EAPIs supporting offset-prefix env variables
11.6 Locale settings for EAPIs
11.7 EAPIs supporting offset-prefix
11.8 Variables that always or never end with a trailing slash
12.1 System commands for EAPIs
12.2 EAPI command failure behaviour
12.3 Banned commands
12.4 Package manager query command options supported by EAPIs
12.5 Output commands for EAPIs
12.6 Properties of die command in EAPIs
12.7 EAPIs supporting pipestatus
12.8 Patch commands for EAPIs
12.9 Extra econf arguments for EAPIs
12.10 EAPIs supporting dodoc -r
12.11 EAPIs supporting doheader and newheader
12.12 EAPIs supporting symlinks for doins
12.13 doman language support options for EAPIs
12.14 EAPIs supporting stdin for new* commands
12.15 domo destination path in EAPIs
12.16 EAPIs supporting dosym -r
12.17 Commands respecting insopts for EAPIs
12.18 Commands respecting exeopts for EAPIs
12.19 Commands controlling manipulation of files in the staging area in EAPIs
12.20 EAPI behaviour for use queries not in IUSE_EFFECTIVE
12.21 usev, use_with and use_enable arguments for EAPIs
12.22 EAPIs supporting usex and in_iuse
12.23 EAPIs supporting version manipulation commands
12.24 unpack behaviour for EAPIs
12.25 unpack extensions for EAPIs
12.26 Misc commands for EAPIs
13.1 Preservation of file modification times (mtimes)
13.2 Rewriting of absolute symlinks in EAPIs
D.1 Features in EAPIs

## Chapter 1
Introduction

### 1.1 Aims and motivation

This document aims to fully describe the format of an ebuild repository and the ebuilds therein, as well as certain aspects of package manager behaviour required to support such a repository.

This document is not designed to be an introduction to ebuild development. Prior knowledge of ebuild creation and an understanding of how the package management system works is assumed; certain less familiar terms are explained in the Glossary.

This document does not specify any user or package manager configuration information.

### 1.2 Rationale

At present the only definition of what an ebuild can assume about its environment, and the only definition of what is valid in an ebuild, is the source code of the latest Portage release and a general consensus about which features are too new to assume availability. This has several drawbacks: not only is it impossible to change any aspect of Portage behaviour without verifying that nothing in the tree relies upon it, but if a new package manager should appear it becomes impossible to fully support such an ill-defined standard.

This document aims to address both of these concerns by defining almost all aspects of what an ebuild repository looks like, and how an ebuild is allowed to behave. Thus, both Portage and other package managers can change aspects of their behaviour not defined here without worry of incompatibilities with any particular repository.

### 1.3 Reporting issues

Issues (inaccuracies, wording problems, omissions etc.) in this document should be reported via Gentoo Bugzilla using product Gentoo Hosted Projects, component PMS/EAPI and the default assignee. There should be one bug per issue, and one issue per bug.

Patches (in git format-patch form if possible) may be submitted either via Bugzilla or to the gentoo-pms@lists.gentoo.org mailing list. Patches will be reviewed by the PMS team, who will do one of the following:

- Accept and apply the patch.
- Explain why the patch cannot be applied as-is. The patch may then be updated and resubmitted if appropriate.
- Reject the patch outright.
- Take special action merited by the individual circumstances.

When reporting issues, remember that this document is not the appropriate place for pushing through changes to the tree or the package manager, except where those changes are bugs.

If any issue cannot be resolved by the PMS team, it may be escalated to the Gentoo Council.

### 1.4 Conventions

Text in teletype is used for filenames or variable names. Italic text is used for terms with a particular technical meaning in places where there may otherwise be ambiguity.

The term package manager is used throughout this document in a broad sense. Although some parts of this document are only relevant to fully featured package managers, many items are equally applicable to tools or other applications that interact with ebuilds or ebuild repositories.

### 1.5 Acknowledgements

Thanks to Mike Kelly (package manager provided utilities, section 12.3), Danny van Dyk (ebuild functions, chapter 9), David Leverton (various sections), Petteri Räty (environment state, section 11.2), Michał Górny (various sections), Andreas K. Hüttel (stable use masking, section 5.2.12), Zac Medico (sub-slots, section 7.2) and James Le Cuirot (build dependencies, section 11.1) for contributions. Thanks also to Mike Frysinger and Brian Harring for proof-reading and suggestions for fixes and/or clarification.

## Chapter 2
EAPIs

### 2.1 Definition

An EAPI can be thought of as a ‘version’ of this specification to which a package conforms. An EAPI value is a string as per section 3.1.9, and is part of an ebuild’s metadata.

If a package manager encounters a package version with an unrecognised EAPI, it must not attempt to perform any operations upon it. It could, for example, ignore the package version entirely (although this can lead to user confusion), or it could mark the package version as masked. A package manager must not use any metadata generated from a package with an unrecognised EAPI.

The package manager must not attempt to perform any kind of comparison test other than equality upon EAPIs.

EAPIs are also used for profile directories, as described in section 5.2.2.

### 2.2 Defined EAPIs

This specification defines EAPIs ‘0’, ‘1’, ‘2’, ‘3’, ‘4’, ‘5’, ‘6’, ‘7’, ‘8’, and ‘9’. EAPI ‘0’ is the ‘original’ base EAPI. Each of the later EAPIs contains a number of extensions to its predecessor.

Except where explicitly noted, everything in this specification applies to all of the above EAPIs.

### 2.3 Reserved EAPIs

- EAPIs whose value consists purely of an integer are reserved for future versions of this specification.
- EAPIs whose value starts with the string paludis- are reserved for experimental use by the Paludis package manager.

## Chapter 3
Names and versions

### 3.1 Restrictions upon names

No name may be empty. Package managers must not impose fixed upper boundaries upon the length of any name. A package manager should indicate or reject any name that is invalid according to these rules.

#### 3.1.1 Category names

A category name may contain any of the characters [A-Za-z0-9+_.-]. It must not begin with a hyphen, a dot or a plus sign.

#### 3.1.2 Package names

A package name may contain any of the characters [A-Za-z0-9+_-]. It must not begin with a hyphen or a plus sign, and must not end in a hyphen followed by anything matching the version syntax described in section 3.2.

  Note: A package name does not include the category. The term qualified package name is used where a category/package pair is meant.

#### 3.1.3 Slot names

A slot name may contain any of the characters [A-Za-z0-9+_.-]. It must not begin with a hyphen, a dot or a plus sign.

#### 3.1.4 USE flag names

A USE flag name may contain any of the characters [A-Za-z0-9+_@-]. It must begin with an alphanumeric character. Underscores should be considered reserved for USE_EXPAND, as described in section 11.1.1.

  Note: Usage of the at-sign is deprecated. It was previously required for LINGUAS.

#### 3.1.5 Repository names

A repository name may contain any of the characters [A-Za-z0-9_-]. It must not begin with a hyphen. In addition, every repository name must also be a valid package name.

#### 3.1.6 Eclass names

An eclass name may contain any of the characters [A-Za-z0-9_.-]. It must begin with a letter or an underscore. In addition, an eclass cannot be named default.

#### 3.1.7 License names

A license name may contain any of the characters [A-Za-z0-9+_.-]. It must not begin with a hyphen, a dot or a plus sign.

#### 3.1.8 Keyword names

A keyword name may contain any of the characters [A-Za-z0-9_-]. It must not begin with a hyphen. In contexts where it makes sense to do so, a keyword name may be prefixed by a tilde or a hyphen. In KEYWORDS, -* is also acceptable as a keyword.

#### 3.1.9 EAPI names

An EAPI name may contain any of the characters [A-Za-z0-9+_.-]. It must not begin with a hyphen, a dot or a plus sign.

### 3.2 Version specifications

The package manager must neither impose fixed limits upon the number of version components, nor upon the length of any component. Package managers should indicate or reject any version that is invalid according to the rules below.

A version starts with the number part, which is in the form [0-9]+(\.[0-9]+)* (an unsigned integer, followed by zero or more dot-prefixed unsigned integers).

This may optionally be followed by one of [a-z] (a lower-case letter).

This may be followed by zero or more suffixes. Each suffix consists of one of the strings _alpha, _beta, _pre, _rc or _p indicating its type, optionally followed by an unsigned integer. The type part and the integer part of the suffix count as separate version components.

This may optionally be followed by the suffix -r followed immediately by an unsigned integer (the “revision number”). If this suffix is not present, it is assumed to be -r0.

### 3.3 Version comparison

Version specifications are compared component by component, moving from left to right, as detailed in algorithm 3.1 and sub-algorithms. If a sub-algorithm returns a decision, then that is the result of the whole comparison; if it terminates without returning a decision, the process continues from the point from which it was invoked.

Algorithm 3.1: Version comparison top-level logic
1: let A and B be the versions to be compared
2: compare numeric components using algorithm 3.2
3: compare letter components using algorithm 3.4
4: compare suffixes using algorithm 3.5
5: compare revision components using algorithm 3.7
6: return A = B

Algorithm 3.2: Version comparison logic for numeric components
1: define the notations Ank and Bnk to mean the kth numeric component of A and B respectively, using 0-based indexing
2: if An0 > Bn0 using integer comparison then
3: return A > B
4: else if An0 < Bn0 using integer comparison then
5: return A < B
6: end if
7: let Ann be the number of numeric components of A
8: let Bnn be the number of numeric components of B
9: for all i such that i ≥ 1 and i < Ann and i < Bnn, in ascending order do
10: compare Ani and Bni using algorithm 3.3
11: end for
12: if Ann > Bnn then
13: return A > B
14: else if Ann < Bnn then
15: return A < B
16: end if

Algorithm 3.3: Version comparison logic for each numeric component after the first
1: if either Ani or Bni has a leading 0 then
2: let An′i be Ani with any trailing 0s removed
3: let Bn′i be Bni with any trailing 0s removed
4: if An′i > Bn′i using ASCII stringwise comparison then
5: return A > B
6: else if An′i < Bn′i using ASCII stringwise comparison then
7: return A < B
8: end if
9: else
10: if Ani > Bni using integer comparison then
11: return A > B
12: else if Ani < Bni using integer comparison then
13: return A < B
14: end if
15: end if

Algorithm 3.4: Version comparison logic for letter components
1: let Al be the letter component of A if any, otherwise the empty string
2: let Bl be the letter component of B if any, otherwise the empty string
3: if Al > Bl using ASCII stringwise comparison then
4: return A > B
5: else if Al < Bl using ASCII stringwise comparison then
6: return A < B
7: end if

Algorithm 3.5: Version comparison logic for suffixes
1: define the notations Ask and Bsk to mean the kth suffix of A and B respectively, using 0-based indexing
2: let Asn be the number of suffixes of A
3: let Bsn be the number of suffixes of B
4: for all i such that i ≥ 0 and i < Asn and i < Bsn, in ascending order do
5: compare Asi and Bsi using algorithm 3.6
6: end for
7: if Asn > Bsn then
8: if AsBsn is of type _p then
9: return A > B
10: else
11: return A < B
12: end if
13: else if Asn < Bsn then
14: if BsAsn is of type _p then
15: return A < B
16: else
17: return A > B
18: end if
19: end if

Algorithm 3.6: Version comparison logic for each suffix
1: if Asi and Bsi are of the same type (_alpha vs _beta etc) then
2: let As′i be the integer part of Asi if any, otherwise 0
3: let Bs′i be the integer part of Bsi if any, otherwise 0
4: if As′i > Bs′i, using integer comparison then
5: return A > B
6: else if As′i < Bs′i, using integer comparison then
7: return A < B
8: end if
9: else if the type of Asi is greater than the type of Bsi using the ordering _alpha < _beta < _pre < _rc < _p then
10: return A > B
11: else
12: return A < B
13: end if

Algorithm 3.7: Version comparison logic for revision components
1: let Ar be the integer part of the revision component of A if any, otherwise 0
2: let Br be the integer part of the revision component of B if any, otherwise 0
3: if Ar > Br using integer comparison then
4: return A > B
5: else if Ar < Br using integer comparison then
6: return A < B
7: end if

### 3.4 Uniqueness of versions

No two packages in a given repository may have the same qualified package name and equal versions. For example, a repository may not contain more than one of foo-bar/baz-1.0.2, foo-bar/baz-1.0.2-r0 and foo-bar/baz-1.000.2.

## Chapter 4
Tree layout

This chapter defines the layout on-disk of an ebuild repository. In all cases below where a file or directory is specified, a symlink to a file or directory is also valid. In this case, the package manager must follow the operating system’s semantics for symbolic links and must not behave differently from normal.

### 4.1 Top level

An ebuild repository shall occupy one directory on disk, with the following subdirectories:

- One directory per category, whose name shall be the name of the category. The layout of these directories shall be as described in section 4.2.
- A profiles directory, described in section 4.4.
- A licenses directory (optional), described in section 4.5.
- An eclass directory (optional), described in section 4.6.
- A metadata directory (optional), described in section 4.7.
- Other optional support files and directories (skeleton ebuilds or ChangeLogs, for example) may exist but are not covered by this specification. The package manager must ignore any of these files or directories that it does not recognise.

### 4.2 Category directories

Each category provided by the repository (see also: the profiles/categories file, section 4.4) shall be contained in one directory, whose name shall be that of the category. Each category directory shall contain:

- A metadata.xml file, as described in appendix 14.3. Optional.
- Zero or more package directories, one for each package in the category, as described in section 4.3. The name of the package directory shall be the corresponding package name.

Category directories may contain additional files, whose purpose is not covered by this specification. Additional directories that are not for a package may not be present, to avoid conflicts with package name directories; an exception is made for filesystem components whose name starts with a dot, which the package manager must ignore, and for any directory named CVS.

It is not required that a directory exists for each category provided by the repository. A category directory that does not exist shall be considered equivalent to an empty category (and by extension, a package manager may treat an empty category as a category that does not exist).

### 4.3 Package directories

A package directory contains the following:

- Zero or more ebuilds. These are as described in chapter 6 and others.
- A metadata.xml file, as described in appendix 14.3. Optional only for legacy support.
- A ChangeLog, in a format determined by the provider of the repository. Optional.
- A Manifest file, whose format is described in [1]. Can be omitted if the file would be empty.
- A files directory, containing any support files needed by the ebuilds. Optional.

Any ebuild in a package directory must be named name-ver.ebuild, where name is the (unqualified) package name, and ver is the package’s version. Package managers must ignore any ebuild file that does not match these rules.

A package directory that contains no correctly named ebuilds shall be considered a package with no versions. A package with no versions shall be considered equivalent to a package that does not exist (and by extension, a package manager may treat a package that does not exist as a package with no versions).

A package directory may contain other files or directories, whose purpose is not covered by this specification.

### 4.4 The profiles directory

The profiles directory shall contain zero or more profile directories as described in chapter 5, as well as the following files and directories. In any line-based file, lines beginning with a # character are treated as comments, whilst blank lines are ignored. All contents of this directory, with the exception of repo_name, are optional.

The profiles directory may contain an eapi file. This file, if it exists, must contain a single line with the name of an EAPI. This specifies the EAPI to use when handling the profiles directory; a package manager must not attempt to use any repository whose profiles directory requires an EAPI it does not support. If no eapi file is present, EAPI 0 shall be used.

If the repository is not intended to be stand-alone, the contents of these files are to be taken from or merged with the master repository as necessary; this does not apply to the eapi file.

Other files not described by this specification may exist, but may not be relied upon. The package manager must ignore any files in this directory that it does not recognise.

arch.list

  Contains a list, one entry per line, of permissible values for the ARCH variable, and hence permissible keywords for packages in this repository.

categories

  Contains a list, one entry per line, of categories provided by this repository.

eapi

  See above.

info_pkgs

  Contains a list, one entry per line, of qualified package names. Any package matching one of these is to be listed when a package manager displays a ‘system information’ listing.

info_vars

  Contains a list, one entry per line, of profile, configuration, and environment variables which are considered to be of interest. The value of each of these variables may be shown when the package manager displays a ‘system information’ listing.

package.mask

  Contains a list, one entry per line, of package dependency specifications (using the directory’s EAPI). Any package version matching one of these is considered to be masked, and will not be installed regardless of profile unless it is unmasked by the user configuration.

  package-mask-dir For EAPIs listed in table 4.1 as supporting it, package.mask can be a directory instead of a regular file. Files contained in that directory, unless their name begins with a dot, will be concatenated in order of their filename in the POSIX locale and the result will be processed as if it were a single file. Any subdirectories will be ignored.

profiles.desc

  Described below in section 4.4.1.

repo_name

  Contains, on a single line, the name of this repository. The repository name must conform to section 3.1.5.

thirdpartymirrors

  Described below in section 4.4.2.

use.desc

  Contains descriptions of valid global USE flags for this repository. The format is described in section 4.4.3.

use.local.desc

  Contains descriptions of valid local USE flags for this repository, along with the packages to which they apply. The format is as described in section 4.4.3.

desc/

  This directory contains files analogous to use.desc for the various USE_EXPAND variables. Each file in it is named <varname>.desc, where <varname> is the variable name, in lower case, whose possible values the file describes. The format of each file is as for use.desc, described in section 4.4.3. The USE_EXPAND name is not included as a prefix here.

updates/

  This directory is described in section 4.4.4.

Table 4.1: EAPIs supporting a directory for package.mask

EAPI | package.mask can be a directory?
0, 1, 2, 3, 4, 5, 6 | No
7, 8, 9 | Yes

#### 4.4.1 The profiles.desc file

profiles.desc is a line-based file, with the standard commenting rules from section 4.4, containing a list of profiles that are valid for use, along with their associated architecture and status. Each line has the format:

    <keyword> <profile path> <stability>

Where:

- <keyword> is the default keyword for the profile and the ARCH for which the profile is valid.
- <profile path> is the (relative) path from the profiles directory to the profile in question.
- <stability> indicates the stability of the profile. This may be useful for QA tools, which may wish to display warnings with a reduced severity for some profiles. The values stable and dev are widely used, but repositories may use other values.

Fields are whitespace-delimited.

#### 4.4.2 The thirdpartymirrors file

thirdpartymirrors is another simple line-based file, describing the valid mirrors for use with mirror:// URIs in this repository, and the associated download locations. The format of each line is:

    <mirror name> <mirror 1> <mirror 2> ... <mirror n>

Fields are whitespace-delimited. When parsing a URI of the form mirror://name/path/filename, where the path/ part is optional, the thirdpartymirrors file is searched for a line whose first field is name. Then the download URIs in the subsequent fields have path/filename appended to them to generate the URIs from which a download is attempted.

Each mirror name may appear at most once in a file. Behaviour when a mirror name appears multiple times is undefined. Behaviour when a mirror is defined in terms of another mirror is undefined. A package manager may choose to fetch from all of or a subset of the listed mirrors, and may use an order other than the one described.

The mirror with the name equal to the repository’s name (and if the repository has a master, the master’s name) may be consulted for all downloads.

#### 4.4.3 use.desc and related files

use.desc contains descriptions of every valid global USE flag for this repository. It is a line-based file with the standard rules for comments and blank lines. The format of each line is:

    <flagname> - <description>

use.local.desc contains descriptions of every valid local USE flag—those that apply only to a small number of packages, or that have different meanings for different packages. Its format is:

    <category/package>:<flagname> - <description>

Flags must be listed once for each package to which they apply, or if a flag is listed in both use.desc and use.local.desc, it must be listed once for each package for which its meaning differs from that described in use.desc.

#### 4.4.4 The updates directory

updates-filenames The updates directory is used to inform the package manager that a package has moved categories, names, or that a version has changed SLOT. For EAPIs so specified by table 4.2, it contains one file per quarter year, named [1-4]Q-[YYYY] for the first to fourth quarter of a given year, for example 1Q-2004 or 3Q-2006. For other EAPIs, all regular files in this directory will be processed, unless their name begins with a dot.

The format of each file is again line-based, with each line having one of the following formats:

    move <qpn1> <qpn2>
    slotmove <spec> <slot1> <slot2>

The first form, where qpn1 and qpn2 are qualified package names, instructs the package manager that the package qpn1 has changed name, category, or both, and is now called qpn2.

The second form instructs the package manager that any currently installed package version matching package dependency specification spec whose SLOT is set to slot1 should have it updated to slot2.

It is unspecified in what order the files in the updates directory are processed. Lines within each file are processed in ascending order.

At any given time, a name that appears as the origin of a move may not be used as a qualified package name in the repository. A slot that appears as the origin of a slot move may not be used by packages matching the spec of that slot move.

Table 4.2: Naming rules for files in updates directory for EAPIs

EAPI | Files per quarter year?
0, 1, 2, 3, 4, 5, 6, 7 | Yes
8, 9 | No

### 4.5 The licenses directory

The licenses directory shall contain copies of the licenses used by packages in the repository. Each file will be named according to the name used in the LICENSE variable as described in section 7.3, and will contain the complete text of the license in human-readable form. Plain text format is strongly preferred but not required.

### 4.6 The eclass directory

The eclass directory shall contain copies of the eclasses provided by this repository. The format of these files is described in chapter 10. It may also contain, in their own directory, support files needed by these eclasses.

### 4.7 The metadata directory

The metadata directory contains various repository-level metadata that are not contained in profiles/. All contents are optional. In this standard only the cache subdirectory is described; other contents are optional but may include security advisories, DTD files for the various XML files used in the repository, and repository timestamps.

#### 4.7.1 The metadata cache

The metadata/cache directory may contain a cached form of all important ebuild metadata variables. The contents of this directory are described in chapter 14.

## Chapter 5
Profiles

### 5.1 General principles

Generally, a profile defines information specific to a certain ‘type’ of system—it lies somewhere between repository-level defaults and user configuration in that the information it contains is not necessarily applicable to all machines, but is sufficiently general that it should not be left to the user to configure it. Some parts of the profile can be overridden by user configuration, some only by another profile.

The format of a profile is relatively simple. Each profile is a directory containing any number of the files described in this chapter, and possibly inheriting another profile. The files themselves follow a few basic conventions as regards inheritance and format; these are described in the next section. It may also contain any number of subdirectories containing other profiles.

### 5.2 Files that make up a profile

#### 5.2.1 The parent file

A profile may contain a parent file. Each line must contain a relative path to another profile which will be considered as one of this profile’s parents. Any settings from the parent are inherited by this profile, and can be overridden by it. Precise rules for how settings are combined with the parent profile vary between files, and are described below. Parents are handled depth first, left to right, with duplicate parent paths being sourced for every time they are encountered.

It is illegal for a profile’s parent tree to contain cycles. Package manager behaviour upon encountering a cycle is undefined.

This file must not make use of line continuations. Blank lines and those beginning with a # are discarded.

#### 5.2.2 The eapi file

A profile directory may contain an eapi file. This file, if it exists, must contain a single line with the name of an EAPI. This specifies the EAPI to use when handling the directory in question; a package manager must not attempt to use any profile using a directory which requires an EAPI it does not support.

profile-eapi-default If no eapi file is present, the default depends on the EAPI of the top-level profiles directory (see section 4.4). That EAPI shall be used if table 5.1 lists it as “top-level”. Otherwise, EAPI 0 shall be used.

The EAPI is neither inherited via the parent file nor in subdirectories.

Table 5.1: Default EAPI for profiles

EAPI | Default EAPI?
0, 1, 2, 3, 4, 5, 6, 7, 8 | 0
9 | Top-level

#### 5.2.3 deprecated

If a profile contains a file named deprecated, it is treated as such. The first line of this file should contain the path from the profiles directory of the repository to a valid profile that is the recommended upgrade path from this profile. The remainder of the file can contain any text, which may be displayed to users using this profile by the package manager. This file is not inherited—profiles which inherit from a deprecated profile are not deprecated.

This file must not contain comments or make use of line continuations.

#### 5.2.4 make.defaults

make.defaults is used to define defaults for various environment and configuration variables. This file is unusual in that it is not combined at a file level with the parent—instead, each variable is combined or overridden individually as described in section 5.3.

The file itself is a line-based key-value format. Each line contains a single VAR="value" entry, where the value must be double quoted. A variable name must start with one of a-zA-Z and may contain a-zA-Z0-9_ only. Additional syntax, which is a small subset of bash syntax, is allowed as follows:

- Variables to the right of the equals sign in the form ${foo} or $foo are recognised and expanded from variables previously set in this or earlier make.defaults files.
- One logical line may be continued over multiple physical lines by escaping the newline with a backslash. A quoted string may be continued over multiple physical lines by either a simple newline or a backslash-escaped newline.
- Backslashes, except for line continuations, are not allowed.

#### 5.2.5 Simple line-based files

These files are a simple one-item-per-line list, which is inherited in the following manner: the parent profile’s list is taken, and the current profile’s list appended. If any line begins with a hyphen, then any lines previous to it whose contents are equal to the remainder of that line are removed from the list. Blank lines and those beginning with a # are discarded.

profile-file-dirs In EAPIs listed in table 5.2 as supporting directories for profile files, any of the files package.mask, package.use, use.* and package.use.* mentioned below can be a directory instead of a regular file. Files contained in that directory, unless their name begins with a dot, will be concatenated in order of their filename in the POSIX locale and the result will be processed as if it were a single file. Any subdirectories will be ignored.

Table 5.2: EAPIs supporting directories for profile files

EAPI | Supports directories for profile files?
0, 1, 2, 3, 4, 5, 6 | No
7, 8, 9 | Yes

#### 5.2.6 packages

The packages file is used to define the ‘system set’ for this profile. After the above rules for inheritance and comments are applied, its lines must take one of two forms: a package dependency specification prefixed by * denotes that it forms part of the system set. A package dependency specification on its own may also appear for legacy reasons, but should be ignored when calculating the system set.

#### 5.2.7 packages.build

The packages.build file is used by Gentoo’s Catalyst tool to generate stage1 tarballs, and has no relevance to the operation of a package manager. It is thus outside the scope of this document, but is mentioned here for completeness.

#### 5.2.8 package.mask

package.mask is used to prevent packages from being installed on a given profile. Each line contains one package dependency specification; anything matching this specification will not be installed unless unmasked by the user’s configuration. In some EAPIs, package.mask can be a directory instead of a regular file as per section 5.2.5.

Note that the -spec syntax can be used to remove a mask in a parent profile, but not necessarily a global mask (from profiles/package.mask, section 4.4).

  Note: Portage currently treats profiles/package.mask as being on the leftmost branch of the inherit tree when it comes to -lines. This behaviour may not be relied upon.

#### 5.2.9 package.provided

package-provided package.provided is used to tell the package manager that a certain package version should be considered to be provided by the system regardless of whether it is actually installed. Because it has severe adverse effects on USE-based and slot-based dependencies, its use is strongly deprecated and package manager support must be regarded as purely optional. Supported in EAPIs as per table 5.3.

Table 5.3: EAPIs supporting package.provided in profiles

EAPI | Supports package.provided?
0, 1, 2, 3, 4, 5, 6 | Optionally
7, 8, 9 | No

#### 5.2.10 package.use

The package.use file may be used by the package manager to override the default USE flags specified by make.defaults on a per package basis. The format is to have a package dependency specification, and then a space delimited list of USE flags to enable. A USE flag in the form of -flag indicates that the package should have the USE flag disabled. The package dependency specification is limited to the forms defined by the directory’s EAPI. In some EAPIs, package.use can be a directory instead of a regular file as per section 5.2.5.

#### 5.2.11 use.stable and package.use.stable

use-stable The use.stable and package.use.stable files may be used to override the default USE flags specified by make.defaults. They only apply to packages that are merged due to a stable keyword in the sense of section 7.3.3. Each line in use.stable contains a USE flag to enable; the -flag syntax indicates that the flag should be disabled. The package.use.stable file uses the same format as package.use. USE_EXPAND values may be enabled or disabled by using expand_name_value.

Stable restrictions are applied exactly when the following condition holds: If every stable keyword in KEYWORDS were replaced with its tilde-prefixed counterpart (see section 7.3.3), then the resulting KEYWORDS setting would prevent installation of the package.

If a flag appears in more than one of package.use, use.stable and package.use.stable, then package.use.stable takes precedence over package.use, which in turn takes precedence over use.stable.

These files are supported in EAPIs as per table 5.4. They can be directories instead of regular files as per section 5.2.5.

Table 5.4: EAPIs supporting use.stable and package.use.stable in profiles

EAPI | Supports use.stable? | Supports package.use.stable?
0, 1, 2, 3, 4, 5, 6, 7, 8 | No | No
9 | Yes | Yes

#### 5.2.12 USE masking and forcing

This section covers the eight files use.mask, use.force, use.stable.mask, use.stable.force, package.use.mask, package.use.force, package.use.stable.mask, and package.use. stable.force. They are described together because they interact in a non-trivial manner. In some EAPIs, these files can be directories instead of regular files as per section 5.2.5.

Simply speaking, use.mask and use.force are used to say that a given USE flag must never or always, respectively, be enabled when using this profile. package.use.mask and package.use.force do the same thing on a per-package, or per-version, basis.

stablemask In profile directories with an EAPI supporting stable masking, as listed in table 5.5, the same is true for use.stable.mask, use.stable.force, package.use.stable.mask and package.use.stable.force. These files, however, only act on packages that are merged due to a stable keyword in the sense of section 7.3.3. Thus, these files can be used to restrict the feature set deemed stable in a package.

Table 5.5: Profile directory support for masking/forcing use flags in stable versions only

EAPI | Supports masking/forcing use flags in stable versions?
0, 1, 2, 3, 4 | No
5, 6, 7, 8, 9 | Yes

The precise manner in which the eight files interact is less simple, and is best described in terms of the algorithm used to determine whether a flag is masked for a given package version. This is described in algorithm 5.1.

Algorithm 5.1: USE masking logic
1: let masked = false
2: for each profile in the inheritance tree, depth first do
3: if use.mask contains flag then
4: let masked = true
5: else if use.mask contains -flag then
6: let masked = false
7: end if
8: if stable keyword in use then
9: if use.stable.mask contains flag then
10: let masked = true
11: else if use.stable.mask contains -flag then
12: let masked = false
13: end if
14: end if
15: for each line in package.use.mask, in order, for which the spec matches package do
16: if line contains flag then
17: let masked = true
18: else if line contains -flag then
19: let masked = false
20: end if
21: end for
22: if stable keyword in use then
23: for each line in package.use.stable.mask, in order, for which the spec matches package do
24: if line contains flag then
25: let masked = true
26: else if line contains -flag then
27: let masked = false
28: end if
29: end for
30: end if
31: end for

Stable restrictions (“stable keyword in use” in algorithm 5.1) are applied exactly when the following condition holds: If every stable keyword in KEYWORDS were replaced with its tilde-prefixed counterpart (see section 7.3.3), then the resulting KEYWORDS setting would prevent installation of the package.

The logic for use.force, use.stable.force, package.use.force, and package.use. stable.force is identical. If a flag is both masked and forced, the mask is considered to take precedence.

USE_EXPAND values may be forced or masked by using expand_name_value.

A package manager may treat ARCH values that are not the current architecture as being masked.

### 5.3 Profile variables

This section documents variables that have special meaning, or special behaviour, when defined in a profile’s make.defaults file.

#### 5.3.1 Incremental variables

Incremental variables must stack between parent and child profiles in the following manner: Beginning with the highest parent profile, tokenise the variable’s value based on whitespace and concatenate the lists. Then, for any token T beginning with a hyphen, remove it and any previous tokens whose value is equal to T with the hyphen removed, or, if T is equal to -*, remove all previous values. Note that because of this treatment, the order of tokens in the final result is arbitrary, not necessarily related to the order of tokens in any given profile. The following variables must be treated in this fashion:

- USE
- USE_EXPAND
- USE_EXPAND_HIDDEN
- CONFIG_PROTECT
- CONFIG_PROTECT_MASK

If the package manager supports any EAPI listed in table 5.6 as using profile-defined IUSE injection, the following variables must also be treated incrementally; otherwise, the following variables may or may not be treated incrementally:

- IUSE_IMPLICIT
- USE_EXPAND_IMPLICIT
- USE_EXPAND_UNPREFIXED

If the package manager supports any EAPI listed in table 5.7 as using ENV_UNSET, the following variable must also be treated incrementally; otherwise, it may or may not be treated incrementally:

- ENV_UNSET

Other variables, except where they affect only package-manager-specific functionality (such as Portage’s FEATURES variable), must not be treated incrementally—later definitions shall completely override those in parent profiles.

Table 5.6: Profile-defined IUSE injection for EAPIs

EAPI | Supports profile-defined IUSE injection?
0, 1, 2, 3, 4 | No
5, 6, 7, 8, 9 | Yes

Table 5.7: Profile-defined unsetting of variables in EAPIs

EAPI | Supports ENV_UNSET?
0, 1, 2, 3, 4, 5, 6 | No
7, 8, 9 | Yes

#### 5.3.2 Specific variables and their meanings

The following variables have specific meanings when set in profiles.

ARCH

  The system’s architecture. Must be a value listed in profiles/arch.list; see section 4.4 for more information. Must be equal to the primary KEYWORD for this profile.

CONFIG_PROTECT, CONFIG_PROTECT_MASK

  Contain whitespace-delimited lists used to control the configuration file protection. Described more fully in section 13.3.3.

USE

  Defines the list of default USE flags for this profile. Flags may be added or removed by the user’s configuration. USE_EXPAND values must not be specified in this way.

USE_EXPAND

  Defines a list of variables which are to be treated incrementally, exported to the ebuild environment, and whose contents are to be expanded into the USE variable as passed to ebuilds. See section 11.1.1 for details.

USE_EXPAND_UNPREFIXED

  Similar to USE_EXPAND, but no prefix is used. If the repository contains any package using an EAPI supporting profile-defined IUSE injection (see table 5.6), this list must contain at least ARCH. See section 11.1.1 for details.

USE_EXPAND_HIDDEN

  Contains a (possibly empty) subset of names from USE_EXPAND and USE_EXPAND_UNPREFIXED. The package manager may use this set as a hint to avoid displaying uninteresting or unhelpful information to an end user.

USE_EXPAND_IMPLICIT, IUSE_IMPLICIT

  Used to inject implicit values into IUSE. See section 11.1.1 for details. USE_EXPAND_IMPLICIT contains a subset of names from USE_EXPAND and USE_EXPAND_UNPREFIXED.

ENV_UNSET

  Contains a whitespace-delimited list of variables that the package manager shall unset. See section 11.1 for details.

In addition, for EAPIs listed in table 5.6 as supporting profile defined IUSE injection, the following variables have special handling as described in section 11.1.1:

- All variables named in USE_EXPAND and USE_EXPAND_UNPREFIXED.
- All USE_EXPAND_VALUES_${v} variables, where ${v} is a value in USE_EXPAND_IMPLICIT.

Any other variables set in make.defaults must be passed on into the ebuild environment as-is, and are not required to be interpreted by the package manager.

## Chapter 6
Ebuild file format

bash-version The ebuild file format is in its basic form a subset of the format of a bash script. The interpreter is assumed to be GNU bash, version as listed in table 6.1, or any later version. If possible, the package manager should set the shell’s compatibility level to the exact version specified. It must ensure that any such compatibility settings (e. g. the BASH_COMPAT variable) are not exported to external programs.

The file creation mask (umask) is set to 022 in the shell execution environment. It is not saved between phase functions but always reset to this initial value.

failglob For EAPIs listed such in table 6.1, the failglob option of bash is set in the global scope of ebuilds. If set, failed pattern matches during filename expansion result in an error when the ebuild is being sourced.

Name reference variables (introduced in bash version 4.3) must not be used, except in local scope.

The file encoding must be UTF-8 with Unix-style newlines. When sourced, the ebuild must define certain variables and functions (see chapters 7 and 9 for specific information), and must not call any external programs, write anything to standard output or standard error, or modify the state of the system in any way.

Table 6.1: Bash version and options

EAPI | Bash version | failglob in global scope?
0, 1, 2, 3, 4, 5 | 3.2 | No
6, 7 | 4.2 | Yes
8 | 5.0 | Yes
9 | 5.3 | Yes

## Chapter 7
Ebuild-defined variables

  Note: This chapter describes variables that may or must be defined by ebuilds. For variables that are passed from the package manager to the ebuild, see section 11.1.

If any of these variables are set to invalid values, or if any of the mandatory variables are undefined, the package manager’s behaviour is undefined; ideally, an error in one ebuild should not prevent operations upon other ebuilds or packages.

### 7.1 Metadata invariance

All ebuild-defined variables discussed in this chapter must be defined independently of any system, profile or tree dependent data, and must not vary depending upon the ebuild phase. In particular, ebuild metadata can and will be generated on a different system from that upon which the ebuild will be used, and the ebuild must generate identical metadata every time it is used.

Globally defined ebuild variables without a special meaning must similarly not rely upon variable data.

### 7.2 Mandatory ebuild-defined variables

All ebuilds must define at least the following variables:

DESCRIPTION

  A short human-readable description of the package’s purpose. May be defined by an eclass. Must not be empty.

SLOT

  The package’s slot. Must be a valid slot name, as per section 3.1.3. May be defined by an eclass. Must not be empty.

  In EAPIs shown in table 8.7 as supporting sub-slots, the SLOT variable may contain an optional sub-slot part that follows the regular slot and is delimited by a / character. The sub-slot must be a valid slot name, as per section 3.1.3. The sub-slot is used to represent cases in which an upgrade to a new version of a package with a different sub-slot may require dependent packages to be rebuilt. When the sub-slot part is omitted from the SLOT definition, the package is considered to have an implicit sub-slot which is equal to the regular slot.

### 7.3 Optional ebuild-defined variables

Ebuilds may define any of the following variables. Unless otherwise stated, any of them may be defined by an eclass.

EAPI

  The EAPI. See below in section 7.3.1.

HOMEPAGE

  The URI or whitespace separated URIs for a package’s homepage, including the scheme component.

SRC_URI

  A list of source URIs for the package. Valid protocols are http://, https://, ftp:// and mirror:// (see section 4.4.2 for mirror behaviour). Fetch restricted packages may include URL parts consisting of just a filename. See section 7.3.2 for description and section 8.2 for full syntax.

LICENSE

  The package’s license. Each text token must be a valid license name, as per section 3.1.7, and must correspond to a tree “licenses/” entry (see section 4.5). See section 8.2 for full syntax.

KEYWORDS

  A whitespace separated list of keywords for the ebuild. Each token must be a valid keyword name, as per section 3.1.8. See section 7.3.3 for full syntax.

IUSE

  The USE flags used by the ebuild. Any eclass that works with USE flags must also set IUSE, listing only the variables used by that eclass. The package manager is responsible for merging these values. See section 11.1.1 for discussion on which values must be listed in this variable.

  iuse-defaults In EAPIs shown in table 7.1 as supporting IUSE defaults, any use flag name in IUSE may be prefixed by at most one of a plus or a minus sign. If such a prefix is present, the package manager may use it as a suggestion as to the default value of the use flag if no other configuration overrides it.

REQUIRED_USE

  required-use Zero or more assertions that must be met by the configuration of USE flags to be valid for this ebuild. See section 7.3.4 for description and section 8.2 for full syntax. Only in EAPIs listed in table 7.2 as supporting REQUIRED_USE.

PROPERTIES

  properties Zero or more properties for this package. See section 7.3.5 for value meanings and section 8.2 for full syntax. For EAPIs listed in table 7.2 as having optional support, ebuilds must not rely upon the package manager recognising or understanding this variable in any way.

RESTRICT

  Zero or more behaviour restrictions for this package. See section 7.3.6 for value meanings and section 8.2 for full syntax.

DEPEND

  See chapter 8.

BDEPEND

  See chapter 8.

RDEPEND

  See chapter 8. For some EAPIs, RDEPEND has special behaviour for its value if unset and when used with an eclass. See section 7.3.7 for details.

PDEPEND

  See chapter 8.

IDEPEND

  See chapter 8.

Table 7.1: EAPIs supporting IUSE defaults

EAPI | Supports IUSE defaults?
0 | No
1, 2, 3, 4, 5, 6, 7, 8, 9 | Yes

Table 7.2: EAPIs supporting various ebuild-defined variables

EAPI | Supports PROPERTIES? | Supports REQUIRED_USE?
0, 1, 2, 3 | Optionally | No
4, 5, 6, 7, 8, 9 | Yes | Yes

#### 7.3.1 EAPI

An empty or unset EAPI value is equivalent to 0. Ebuilds must not assume that they will get a particular one of these two values if they are expecting one of these two values.

The package manager must either pre-set the EAPI variable to 0 or ensure that it is unset before sourcing the ebuild for metadata generation. When using the ebuild for other purposes, the package manager must either pre-set EAPI to the value specified by the ebuild’s metadata or ensure that it is unset.

If any of these variables are set to invalid values, the package manager’s behaviour is undefined; ideally, an error in one ebuild should not prevent operations upon other ebuilds or packages.

If the EAPI is to be specified in an ebuild, the EAPI variable must be assigned to precisely once. The assignment must not be preceded by any lines other than blank lines or those that start with optional whitespace (spaces or tabs) followed by a # character, and the line containing the assignment statement must match the following regular expression:

    ^[ \t]*EAPI=([’"]?)([A-Za-z0-9+_.-]*)\1[ \t]*([ \t]#.*)?$

The package manager must determine the EAPI of an ebuild by parsing its first non-blank and non-comment line, using the above regular expression. If it matches, the EAPI is the substring matched by the capturing parentheses (0 if empty), otherwise it is 0. For a recognised EAPI, the package manager must make sure that the EAPI value obtained by sourcing the ebuild with bash is identical to the EAPI obtained by parsing. The ebuild must be treated as invalid if these values are different.

Eclasses must not attempt to modify the EAPI variable.

#### 7.3.2 SRC_URI

All filename components that are enabled (i. e. not inside a use-conditional block that is not matched) in SRC_URI must be available in the DISTDIR directory. In addition, these components are used to make the A and AA variables.

If a component contains a full URI with protocol, that download location must be used. Package managers may also consult mirrors for their files.

The special mirror:// protocol must be supported. See section 4.4.2 for mirror details.

The RESTRICT metadata key can be used to impose additional restrictions upon downloading—see section 7.3.6 for details. Fetch restricted packages may use a simple filename instead of a full URI.

src-uri-arrows In EAPIs listed in table 7.3 as supporting arrows, if an arrow is used, the filename used when saving to DISTDIR shall instead be the name on the right of the arrow. When consulting mirrors (except for those explicitly listed on the left of the arrow, if mirror:// is used), the filename to the right of the arrow shall be requested instead of the filename in the URI.

uri-restrict In EAPIs listed in table 7.3 as supporting selective URI restrictions, the URI protocol can be prefixed by an additional fetch+ or mirror+ term. If the ebuild is fetch restricted, the fetch+ prefix undoes the fetch restriction for the URI (but not the implied mirror restriction). If the ebuild is fetch or mirror restricted, the mirror+ prefix undoes both fetch and mirror restrictions for the URI.

Table 7.3: EAPIs supporting SRC_URI arrows and selective URI restrictions

EAPI | Supports SRC_URI arrows? | Supports selective URI restrictions?
0, 1 | No | No
2, 3, 4, 5, 6, 7 | Yes | No
8, 9 | Yes | Yes

#### 7.3.3 Keywords

Keywords are used to indicate levels of stability of a package on a respective architecture arch. The following conventions are used:

- arch: Both the package version and the ebuild are widely tested, known to work and not have any serious issues on the indicated platform. This is referred to as a stable keyword.
- ~arch: The package version and the ebuild are believed to work and do not have any known serious bugs, but more testing is required before the package version is considered suitable for obtaining a stable keyword. This is referred to as an unstable keyword or a testing keyword.
- No keyword: It is not known whether the package will work, or insufficient testing has occurred.
- -arch: The package version will not work on the architecture.

The -* keyword is used to indicate package versions which are not worth trying to test on unlisted architectures.

An empty KEYWORDS variable indicates uncertain functionality on any architecture.

#### 7.3.4 USE state constraints

REQUIRED_USE contains a list of assertions that must be met by the configuration of USE flags to be valid for this ebuild. In order to be matched, a USE flag in a terminal element must be enabled (or disabled if it has an exclamation mark prefix).

If the package manager encounters a package version where REQUIRED_USE assertions are not met, it must treat this package version as if it was masked. No phase functions must be called.

It is an error for a flag to be used if it is not included in IUSE_EFFECTIVE.

#### 7.3.5 Properties

The following tokens are permitted inside PROPERTIES:

interactive

  The package may require interaction with the user via the tty.

live

  The package uses “live” source code that may vary each time that the package is installed.

test_network

  The package manager may run tests that require an internet connection, even if the ebuild has RESTRICT=test.

test_privileged

  The package manager may run tests that require superuser privileges, even if the ebuild has RESTRICT=test.

Package managers may recognise other tokens. Ebuilds may not rely upon any token being supported.

#### 7.3.6 Restrict

The following tokens are permitted inside RESTRICT:

mirror

  The package’s SRC_URI entries may not be mirrored, and mirrors should not be checked when fetching.

fetch

  The package’s SRC_URI entries may not be downloaded automatically. If entries are not available, pkg_nofetch is called. Implies mirror.

strip

  No stripping of debug symbols from files to be installed may be performed. In EAPIs listed in table 12.19 as supporting controllable stripping, this behaviour may be altered by the dostrip command.

userpriv

  The package manager may not drop superuser privileges when building the package.

test

  The src_test phase must not be run.

Package managers may recognise other tokens, but ebuilds may not rely upon them being supported.

#### 7.3.7 RDEPEND value

rdepend-depend In EAPIs listed in table 7.4 as having RDEPEND=DEPEND, if RDEPEND is unset (but not if it is set to an empty string) in an ebuild, when generating metadata the package manager must treat its value as being equal to the value of DEPEND.

When dealing with eclasses, only values set in the ebuild itself are considered for this behaviour; any DEPEND or RDEPEND set in an eclass does not change the implicit RDEPEND=DEPEND for the ebuild portion, and any DEPEND value set in an eclass does not get treated as being part of RDEPEND.

Table 7.4: EAPIs with RDEPEND=DEPEND default

EAPI | RDEPEND=DEPEND?
0, 1, 2, 3 | Yes
4, 5, 6, 7, 8, 9 | No

### 7.4 Magic ebuild-defined variables

The following variables must be defined by inherit (see section 10.1), and may be considered to be part of the ebuild’s metadata:

ECLASS

  The current eclass, or unset if there is no current eclass. This is handled magically by inherit and must not be modified manually.

INHERITED

  List of inherited eclass names. Again, this is handled magically by inherit.

  Note: Thus, by extension of section 7.1, inherit may not be used conditionally, except upon constant conditions.

The following is a special variable defined by the package manager for internal use and may or may not be available in the ebuild environment:

DEFINED_PHASES

  defined-phases A space separated arbitrarily ordered list of phase names (e. g. configure setup unpack) whose phase functions are defined by the ebuild or an eclass inherited by the ebuild. If no phase functions are defined, a single hyphen is used instead of an empty string. For EAPIs listed in table 7.5 as having optional DEFINED_PHASES support, package managers may not rely upon the metadata cache having this variable defined, and must treat an empty string as “this information is not available”.

  Note: Thus, by extension of section 7.1, phase functions must not be defined based upon any variant condition.

Table 7.5: EAPIs supporting DEFINED_PHASES

EAPI | Supports DEFINED_PHASES?
0, 1, 2, 3 | Optionally
4, 5, 6, 7, 8, 9 | Yes

For EAPIs listed in table 11.1 with the property that variables are not exported, the package manager must not export any of the variables specified in this section to the environment.

## Chapter 8
Dependencies

### 8.1 Dependency classes

Table 8.1: Dependency classes required to be satisfied for a particular phase function

Phase function | Satisfied dependency classes
pkg_pretend, pkg_info, pkg_nofetch | None (ebuilds can rely only on the packages in the system set)
pkg_setup | Same as src_unpack if executed as part of source build, same as pkg_pretend otherwise
src_unpack, src_prepare, src_configure, src_compile, src_test, src_install | DEPEND, BDEPEND
pkg_preinst, pkg_postinst, pkg_prerm, pkg_postrm | RDEPEND, IDEPEND
pkg_config | RDEPEND, PDEPEND

Table 8.2: Summary of other interfaces related to dependency classes

| BDEPEND, IDEPEND | DEPEND | RDEPEND, PDEPEND
Binary compatible with | CBUILD | CHOST | CHOST
Base unprefixed path | / | ${SYSROOT} | ${ROOT}
Relevant offset-prefix | ${BROOT} | See table 8.3 | ${EPREFIX}
Path combined with prefix | ${BROOT} | ${ESYSROOT} | ${EROOT}
PM query command option | -b | -d | -r

Table 8.3: Prefix values for DEPEND

If SYSROOT is: | ${ROOT} | Empty, and ROOT is non-empty | Other
Then offset-prefix is: | ${EPREFIX} | ${BROOT} | Empty
And ESYSROOT is: | ${EROOT} | ${BROOT} | ${SYSROOT}

There are three classes of dependencies supported by ebuilds:

- Build dependencies (DEPEND). These must be installed and usable before the pkg_setup phase function is executed as a part of source build and throughout all src_* phase functions executed as part of that build. These may not be installed at all if a binary package is being merged.
- Runtime dependencies (RDEPEND). These must be installed and usable before the results of an ebuild merging are treated as usable.
- Post dependencies (PDEPEND). These must be installed at some point before the package manager finishes the batch of installs.

bdepend Additionally, in EAPIs listed in table 8.4 as supporting BDEPEND, the build dependencies are split into two subclasses:

- BDEPEND build dependencies that are binary compatible with the native build system (CBUILD). The ebuild is allowed to call binary executables installed by this kind of dependency.
- DEPEND build dependencies that are binary compatible with the system being built (CHOST). The ebuild must not execute binary executables installed by this kind of dependency.

idepend Additionally, in EAPIs listed in table 8.4 as supporting IDEPEND, install-time dependencies can be specified. These dependencies are binary compatible with the native build system (CBUILD). Ebuilds are allowed to call them in pkg_preinst and pkg_postinst. Ebuilds may also call them in pkg_prerm and pkg_postrm but must not rely on them being available.

Table 8.4: EAPIs supporting additional dependency types

EAPI | Supports BDEPEND? | Supports IDEPEND?
0, 1, 2, 3, 4, 5, 6 | No | No
7 | Yes | No
8, 9 | Yes | Yes

Table 8.1 lists dependencies which must be satisfied before a particular phase function is executed. Table 8.2 summarises additional interfaces related to the dependency classes.

In addition, SRC_URI, LICENSE, REQUIRED_USE, PROPERTIES and RESTRICT use dependency-style specifications to specify their values.

### 8.2 Dependency specification format

The following elements are recognised in at least one class of specification. All elements must be surrounded on both sides by whitespace, except at the start and end of the string.

- A package dependency specification. Permitted in DEPEND, BDEPEND, RDEPEND, PDEPEND, IDEPEND.
- A URI, in the form proto://host/path. Permitted in SRC_URI. In EAPIs listed in table 7.3 as supporting SRC_URI arrows, may optionally be followed by whitespace, then ->, then whitespace, then a simple filename. See section 7.3.2.
- A flat filename. Permitted in SRC_URI.
- A license name (e. g. GPL-2). Permitted in LICENSE.
- A use flag name, optionally preceded by an exclamation mark. Permitted in REQUIRED_USE.
- A simple string. Permitted in PROPERTIES and RESTRICT.
- An all-of group, which consists of an open parenthesis, followed by whitespace, followed by one or more of (a dependency item of any kind followed by whitespace), followed by a close parenthesis. More formally: all-of ::= ’(’ whitespace (item whitespace)+ ’)’. Permitted in all specification style variables.
- An any-of group, which consists of the string ||, followed by whitespace, followed by an open parenthesis, followed by whitespace, followed by one or more of (a dependency item of any kind followed by whitespace), followed by a close parenthesis. More formally: any-of ::= ’||’ whitespace ’(’ whitespace (item whitespace)+ ’)’. Permitted in DEPEND, BDEPEND, RDEPEND, PDEPEND, IDEPEND, LICENSE, REQUIRED_USE.
- An exactly-one-of group, which has the same format as the any-of group, but begins with the string ^^ instead. Permitted in REQUIRED_USE.
- at-most-one-of An at-most-one-of group, which has the same format as the any-of group, but begins with the string ?? instead. Permitted in REQUIRED_USE in EAPIs listed in table 8.5 as supporting REQUIRED_USE ?? groups.
- A use-conditional group, which consists of an optional exclamation mark, followed by a use flag name, followed by a question mark, followed by whitespace, followed by an open parenthesis, followed by whitespace, followed by one or more of (a dependency item of any kind followed by whitespace), followed by a close parenthesis. More formally: use-conditional ::= ’!’? flag-name ’?’ whitespace ’(’ whitespace (item whitespace)+ ’)’. Permitted in all specification style variables.

In particular, note that whitespace is not optional.

Table 8.5: EAPIs supporting REQUIRED_USE ?? groups

EAPI | Supports REQUIRED_USE ?? groups?
0, 1, 2, 3, 4 | No
5, 6, 7, 8, 9 | Yes

#### 8.2.1 All-of dependency specifications

In an all-of group, all of the child elements must be matched.

#### 8.2.2 USE-conditional dependency specifications

In a use-conditional group, if the associated use flag is enabled (or disabled if it has an exclamation mark prefix), all of the child elements must be matched.

It is an error for a flag to be used if it is not included in IUSE_EFFECTIVE as described in section 11.1.1.

#### 8.2.3 Any-of dependency specifications

Any use-conditional group that is an immediate child of an any-of group, if not enabled (disabled for an exclamation mark prefixed use flag name), is not considered a member of the any-of group for match purposes.

In an any-of group, at least one immediate child element must be matched. A blocker is considered to be matched if its associated package dependency specification is not matched.

empty-dep-groups In EAPIs specified in table 8.6, an empty any-of group counts as being matched.

#### 8.2.4 Exactly-one-of dependency specifications

Any use-conditional group that is an immediate child of an exactly-one-of group, if not enabled (disabled for an exclamation mark prefixed use flag name), is not considered a member of the exactly-one-of group for match purposes.

In an exactly-one-of group, exactly one immediate child element must be matched.

In EAPIs specified in table 8.6, an empty exactly-one-of group counts as being matched.

Table 8.6: Matching of empty dependency groups in EAPIs

EAPI | Empty || and ^^ groups are matched?
0, 1, 2, 3, 4, 5, 6 | Yes
7, 8, 9 | No

#### 8.2.5 At-most-one-of dependency specifications

Any use-conditional group that is an immediate child of an at-most-one-of group, if not enabled (disabled for an exclamation mark prefixed use flag name), is not considered a member of the at-most-one-of group for match purposes.

In an at-most-one-of group, at most one immediate child element must be matched.

### 8.3 Package dependency specifications

A package dependency can be in one of the following base formats. A package manager must warn or error on non-compliant input.

- A simple category/package name.
- An operator, as described in section 8.3.1, followed immediately by category/package, followed by a hyphen, followed by a version specification.

In EAPIs shown in table 8.7 as supporting SLOT dependencies, either of the above formats may additionally be suffixed by a :slot restriction, as described in section 8.3.3. A package manager must warn or error if slot dependencies are used with an EAPI not supporting SLOT dependencies.

use-deps In EAPIs shown in table 8.8 as supporting 2-style or 4-style USE dependencies, a specification may additionally be suffixed by at most one 2-style or 4-style [use] restriction, as described in section 8.3.4. A package manager must warn or error if this feature is used with an EAPI not supporting use dependencies.

  Note: Order is important. The slot restriction must come before use dependencies.

Table 8.7: Support for SLOT dependencies and sub-slots in EAPIs

EAPI | Supports SLOT dependencies? | Supports sub-slots?
0 | No | No
1, 2, 3, 4 | Named only | No
5, 6, 7, 8, 9 | Named and operator | Yes

Table 8.8: EAPIs supporting USE dependencies

EAPI | Supports USE dependencies?
0, 1 | No
2, 3 | 2-style
4, 5, 6, 7, 8, 9 | 4-style

#### 8.3.1 Operators

The following operators are available:

<

  Strictly less than the specified version.

<=

  Less than or equal to the specified version.

=

  Exactly equal to the specified version. Special exception: if the version specified has an asterisk immediately following it, then only the given number of version components is used for comparison, i. e. the asterisk acts as a wildcard for any further components. When an asterisk is used, the specification must remain valid if the asterisk were removed. (An asterisk used with any other operator is illegal.)

~

  Equal to the specified version when revision parts are ignored.

>=

  Greater than or equal to the specified version.

>

  Strictly greater than the specified version.

#### 8.3.2 Block operator

If the specification is prefixed with one or two exclamation marks, the named dependency is a block rather than a requirement—that is to say, the specified package must not be installed. As an exception, weak blocks on the package version of the ebuild itself do not count.

bang-strength There are two strengths of block: weak and strong. A weak block may be ignored by the package manager, so long as any blocked package will be uninstalled later on. A strong block must not be ignored. The mapping from one or two exclamation marks to strength is described in table 8.9.

Table 8.9: Exclamation mark strengths for EAPIs

EAPI | ! | !!
0, 1 | Unspecified | Forbidden
2, 3, 4, 5, 6, 7, 8, 9 | Weak | Strong

#### 8.3.3 Slot dependencies

slot-deps A named slot dependency consists of a colon followed by a slot name. A specification with a named slot dependency matches only if the slot of the matched package is equal to the slot specified. If the slot of the package to match cannot be determined (e. g. because it is not a supported EAPI, the match is treated as unsuccessful.

sub-slot In EAPIs shown in table 8.7 as supporting sub-slots, a slot dependency may contain an optional sub-slot part that follows the regular slot and is delimited by a / character.

slot-operator-deps An operator slot dependency consists of a colon followed by one of the following operators:

*

  Indicates that any slot value is acceptable. In addition, for runtime dependencies, indicates that the package will not break if the matched package is uninstalled and replaced by a different matching package in a different slot.

=

  Indicates that any slot value is acceptable. In addition, for runtime dependencies, indicates that the package will break unless a matching package with slot and sub-slot equal to the slot and sub-slot of the best version installed as a build-time (DEPEND) dependency is available.

slot=

  Indicates that only a specific slot value is acceptable, and otherwise behaves identically to the = operator. The specified slot must not contain a sub-slot part.

To implement the equals slot operators = and slot=, the package manager will need to store the slot/sub-slot pair of the best installed version of the matching package. This syntax is only for package manager use and must not be used by ebuilds. The package manager may do this by inserting the appropriate slot/sub-slot pair between the colon and equals sign when saving the package’s dependencies. The sub-slot part must not be omitted here (when the SLOT variable omits the sub-slot part, the package is considered to have an implicit sub-slot which is equal to the regular slot).

Whenever the equals slot operator is used in an enabled dependency group, the dependencies (DEPEND) must ensure that a matching package is installed at build time. It is invalid to use the equals slot operator inside PDEPEND or inside any-of dependency specifications.

#### 8.3.4 2-style and 4-style USE dependencies

A 2-style or 4-style use dependency consists of one of the following:

[opt]

  The flag must be enabled.

[opt=]

  The flag must be enabled if the flag is enabled for the package with the dependency, or disabled otherwise.

[!opt=]

  The flag must be disabled if the flag is enabled for the package with the dependency, or enabled otherwise.

[opt?]

  The flag must be enabled if the flag is enabled for the package with the dependency.

[!opt?]

  The flag must be disabled if the use flag is disabled for the package with the dependency.

[-opt]

  The flag must be disabled.

Multiple requirements may be combined using commas, e. g. [first,-second,third?].

When multiple requirements are specified, all must match for a successful match.

use-dep-defaults In a 4-style use dependency, the flag name may immediately be followed by a default specified by either (+) or (-). The former indicates that, when applying the use dependency to a package that does not have the flag in question in IUSE_REFERENCEABLE, the package manager shall behave as if the flag were present and enabled; the latter, present and disabled.

Unless a 4-style default is specified, it is an error for a use dependency to be applied to an ebuild which does not have the flag in question in IUSE_REFERENCEABLE.

  Note: By extension of the above, a default that could reference an ebuild using an EAPI not supporting profile IUSE injections cannot rely upon any particular behaviour for flags that would not have to be part of IUSE.

It is an error for an ebuild to use a conditional use dependency when that ebuild does not have the flag in IUSE_EFFECTIVE.

## Chapter 9
Ebuild-defined functions

### 9.1 List of functions

The following is a list of functions that an ebuild, or eclass, may define, and which will be called by the package manager as part of the build and/or install process. In all cases the package manager must provide a default implementation of these functions; unless otherwise stated this must be a no-op. All functions may assume that they have read access to all system libraries, binaries and configuration files that are accessible to normal users, as well as write access to the temporary directories specified by the T, TMPDIR and HOME variables (see section 11.1). Most functions must assume only that they have additional write access to the package’s working directory (the WORKDIR variable); exceptions are noted below.

The environment for functions run outside of the build sequence (that is, pkg_config, pkg_info, pkg_prerm and pkg_postrm) must be the environment used for the build of the package, not the current configuration.

Ebuilds must not call nor assume the existence of any phase functions.

#### 9.1.1 Initial working directories

phase-function-dir Some functions may assume that their initial working directory is set to a particular location; these are noted below. If no initial working directory is mandated, then for EAPIs listed in table 9.1 as having an empty directory, it must be set to a dedicated directory that is empty at the start of the function and may be read-only. For other EAPIs, it may be set to anything. The ebuild must not rely upon a particular location for it. The ebuild may assume that the initial working directory for any phase is a trusted location that may only be written to by a privileged user and group.

s-workdir-fallback Some functions are described as having an initial working directory of S with an error or fallback to WORKDIR. For EAPIs listed in table 9.2 as having the fallback, this means that if S is not a directory before the start of the phase function, the initial working directory shall be WORKDIR instead. For EAPIs where it is a conditional error, if S is not a directory before the start of the phase function, it is a fatal error, unless all of the following conditions are true, in which case the fallback to WORKDIR is used:

- The A variable contains no items.
- The phase function in question is not in DEFINED_PHASES.
- None of the phase functions unpack, prepare, configure, compile, test or install, if supported by the EAPI in question and occurring prior to the phase about to be executed, are in DEFINED_PHASES.

Table 9.1: Initial working directory in pkg_* phase functions for EAPIs

EAPI | Initial working directory?
0, 1, 2, 3, 4, 5, 6, 7 | Any
8, 9 | Empty

Table 9.2: EAPIs with S to WORKDIR fallbacks

EAPI | Fallback to WORKDIR permitted?
0, 1, 2, 3 | Always
4, 5, 6, 7, 8, 9 | Conditional error

#### 9.1.2 pkg_pretend

pkg-pretend The pkg_pretend function is only called for EAPIs listed in table 9.3 as supporting it.

The pkg_pretend function may be used to carry out sanity checks early on in the install process. For example, if an ebuild requires a particular kernel configuration, it may perform that check in pkg_pretend and call eerror and then die with appropriate messages if the requirement is not met.

pkg_pretend is run separately from the main phase function sequence, and does not participate in any kind of environment saving. There is no guarantee that any of an ebuild’s dependencies will be met at this stage, and no guarantee that the system state will not have changed substantially before the next phase is executed.

pkg_pretend must not write to the filesystem.

Table 9.3: EAPIs supporting pkg_pretend

EAPI | Supports pkg_pretend?
0, 1, 2, 3 | No
4, 5, 6, 7, 8, 9 | Yes

#### 9.1.3 pkg_setup

The pkg_setup function sets up the ebuild’s environment for all following functions, before the build process starts. Further, it checks whether any necessary prerequisites not covered by the package manager, e. g. that certain kernel configuration options are fulfilled.

pkg_setup must be run with full filesystem permissions, including the ability to add new users and/or groups to the system.

#### 9.1.4 src_unpack

The src_unpack function extracts all of the package’s sources. In EAPIs lacking src_prepare, it may also apply patches and set up the package’s build system for further use.

The initial working directory must be WORKDIR, and the default implementation used when the ebuild lacks the src_unpack function shall behave as in listing 9.1.

Listing 9.1: src_unpack

    src_unpack() {
        if [[ -n ${A} ]]; then
            unpack ${A}
        fi
    }

#### 9.1.5 src_prepare

src-prepare The src_prepare function is only called for EAPIs listed in table 9.4 as supporting it. The src_prepare function can be used for post-unpack source preparation.

The initial working directory is S, with an error or fallback to WORKDIR as discussed in section 9.1.1.

For EAPIs listed in table 9.4 as using format 6 or 8, the default implementation used when the ebuild lacks the src_prepare function shall behave as in listing 9.2 or listing 9.3, respectively.

For other EAPIs supporting src_prepare, the default implementation used when the ebuild lacks the src_prepare function is a no-op.

Table 9.4: src_prepare support and behaviour for EAPIs

EAPI | Supports src_prepare? | Format
0, 1 | No | Not applicable
2, 3, 4, 5 | Yes | no-op
6, 7 | Yes | 6
8, 9 | Yes | 8

Listing 9.2: src_prepare, format 6

    src_prepare() {
        if [[ $(declare -p PATCHES 2>/dev/null) == "declare -a"* ]]; then
            [[ -n ${PATCHES[@]} ]] && eapply "${PATCHES[@]}"
        else
            [[ -n ${PATCHES} ]] && eapply ${PATCHES}
        fi
        eapply_user
    }

Listing 9.3: src_prepare, format 8

    src_prepare() {
        if [[ ${PATCHES@a} == *a* ]]; then
            [[ -n ${PATCHES[@]} ]] && eapply -- "${PATCHES[@]}"
        else
            [[ -n ${PATCHES} ]] && eapply -- ${PATCHES}
        fi
        eapply_user
    }

#### 9.1.6 src_configure

src-configure The src_configure function is only called for EAPIs listed in table 9.5 as supporting it.

The initial working directory is S, with an error or fallback to WORKDIR as discussed in section 9.1.1.

The src_configure function configures the package’s build environment. The default implementation used when the ebuild lacks the src_configure function shall behave as in listing 9.4.

Table 9.5: EAPIs supporting src_configure

EAPI | Supports src_configure?
0, 1 | No
2, 3, 4, 5, 6, 7, 8, 9 | Yes

Listing 9.4: src_configure

    src_configure() {
        if [[ -x ${ECONF_SOURCE:-.}/configure ]]; then
            econf
        fi
    }

#### 9.1.7 src_compile

src-compile The src_compile function configures the package’s build environment in EAPIs lacking src_configure, and builds the package in all EAPIs.

The initial working directory is S, with an error or fallback to WORKDIR as discussed in section 9.1.1.

For EAPIs listed in table 9.6 as using format 0, 1 or 2, the default implementation used when the ebuild lacks the src_prepare function shall behave as in listing 9.5, listing 9.6 or listing 9.7, respectively.

Table 9.6: src_compile behaviour for EAPIs

EAPI | Format
0 | 0
1 | 1
2, 3, 4, 5, 6, 7, 8, 9 | 2

Listing 9.5: src_compile, format 0

    src_compile() {
        if [[ -x ./configure ]]; then
            econf
        fi
        if [[ -f Makefile ]] || [[ -f GNUmakefile ]] || [[ -f makefile ]]; then
            emake || die "emake failed"
        fi
    }

Listing 9.6: src_compile, format 1

    src_compile() {
        if [[ -x ${ECONF_SOURCE:-.}/configure ]]; then
            econf
        fi
        if [[ -f Makefile ]] || [[ -f GNUmakefile ]] || [[ -f makefile ]]; then
            emake || die "emake failed"
        fi
    }

Listing 9.7: src_compile, format 2

    src_compile() {
        if [[ -f Makefile ]] || [[ -f GNUmakefile ]] || [[ -f makefile ]]; then
            emake || die "emake failed"
        fi
    }

#### 9.1.8 src_test

The src_test function runs unit tests for the newly built but not yet installed package as provided.

The initial working directory is S, with an error or fallback to WORKDIR as discussed in section 9.1.1.

The default implementation used when the ebuild lacks the src_test function must, if tests are enabled, run emake check if and only if such a target is available, or if not run emake test if and only if such a target is available. In both cases, if emake returns non-zero the build must be aborted.

parallel-tests For EAPIs listed in table 9.7 as not supporting parallel tests, the emake command must be called with option -j1.

The src_test function may be disabled by RESTRICT. See section 7.3.6. It may be disabled by user too, using a PM-specific mechanism.

Table 9.7: src_test behaviour for EAPIs

EAPI | Supports parallel tests?
0, 1, 2, 3, 4 | No
5, 6, 7, 8, 9 | Yes

#### 9.1.9 src_install

src-install The src_install function installs the package’s content to a directory specified in D.

The initial working directory is S, with an error or fallback to WORKDIR as discussed in section 9.1.1.

For EAPIs listed in table 9.8 as using format 4 or 6, the default implementation used when the ebuild lacks the src_prepare function shall behave as in listing 9.8 or listing 9.9, respectively.

For other EAPIs, the default implementation used when the ebuild lacks the src_install function is a no-op.

Table 9.8: src_install behaviour for EAPIs

EAPI | Format
0, 1, 2, 3 | no-op
4, 5 | 4
6, 7, 8, 9 | 6

Listing 9.8: src_install, format 4

    src_install() {
        if [[ -f Makefile ]] || [[ -f GNUmakefile ]] || [[ -f makefile ]]; then
            emake DESTDIR="${D}" install
        fi

        if ! declare -p DOCS >/dev/null 2>&1; then
            local d
            for d in README* ChangeLog AUTHORS NEWS TODO CHANGES \
                    THANKS BUGS FAQ CREDITS CHANGELOG; do
                [[ -s "${d}" ]] && dodoc "${d}"
            done
        elif [[ $(declare -p DOCS) == "declare -a"* ]]; then
            dodoc "${DOCS[@]}"
        else
            dodoc ${DOCS}
        fi
    }

Listing 9.9: src_install, format 6

    src_install() {
        if [[ -f Makefile ]] || [[ -f GNUmakefile ]] || [[ -f makefile ]]; then
            emake DESTDIR="${D}" install
        fi
        einstalldocs
    }

#### 9.1.10 pkg_preinst

The pkg_preinst function performs any special tasks that are required immediately before merging the package to the live filesystem. It must not write outside of the directories specified by the ROOT and D variables.

pkg_preinst must be run with full access to all files and directories below that specified by the ROOT and D variables.

#### 9.1.11 pkg_postinst

The pkg_postinst function performs any special tasks that are required immediately after merging the package to the live filesystem. It must not write outside of the directory specified in the ROOT variable.

pkg_postinst, like, pkg_preinst, must be run with full access to all files and directories below that specified by the ROOT variable.

#### 9.1.12 pkg_prerm

The pkg_prerm function performs any special tasks that are required immediately before unmerging the package from the live filesystem. It must not write outside of the directory specified by the ROOT variable.

pkg_prerm must be run with full access to all files and directories below that specified by the ROOT variable.

#### 9.1.13 pkg_postrm

The pkg_postrm function performs any special tasks that are required immediately after unmerging the package from the live filesystem. It must not write outside of the directory specified by the ROOT variable.

pkg_postrm must be run with full access to all files and directories below that specified by the ROOT variable.

#### 9.1.14 pkg_config

The pkg_config function performs any custom steps required to configure a package after it has been fully installed. It is the only ebuild function which may be interactive and prompt for user input.

pkg_config must be run with full access to all files and directories inside of ROOT.

#### 9.1.15 pkg_info

pkg-info The pkg_info function may be called by the package manager when displaying information about an installed package. In EAPIs listed in table 9.9 as supporting pkg_info on non-installed packages, it may also be called by the package manager when displaying information about a non-installed package. In this case, ebuild authors should note that dependencies may not be installed.

pkg_info must not write to the filesystem.

Table 9.9: EAPIs supporting pkg_info on non-installed packages

EAPI | Supports pkg_info on non-installed packages?
0, 1, 2, 3 | No
4, 5, 6, 7, 8, 9 | Yes

#### 9.1.16 pkg_nofetch

The pkg_nofetch function is run when the fetch phase of an fetch-restricted ebuild is run, and the relevant source files are not available. It should direct the user to download all relevant source files from their respective locations, with notes concerning licensing if applicable.

pkg_nofetch must require no write access to any part of the filesystem.

#### 9.1.17 Default phase functions

default-phase-funcs In EAPIs listed in table 9.10 as supporting default_ phase functions, a function named default_<phase-function>) that behaves as the default implementation for that EAPI shall be defined when executing any ebuild phase function listed in the table. Ebuilds must not call these functions except when in the phase in question.

Table 9.10: EAPIs supporting default_ phase functions

EAPI | Supports default_ functions in phases
0, 1 | None
2, 3 | pkg_nofetch, src_unpack, src_prepare, src_configure, src_compile, src_test
4, 5, 6, 7, 8, 9 | pkg_nofetch, src_unpack, src_prepare, src_configure, src_compile, src_test, src_install

### 9.2 Call order

The call order for installing a package is:

- pkg_pretend (only for EAPIs listed in table 9.3), which is called outside of the normal call order process.
- pkg_setup
- src_unpack
- src_prepare (only for EAPIs listed in table 9.4)
- src_configure (only for EAPIs listed in table 9.5)
- src_compile
- src_test (except if RESTRICT=test or disabled by user)
- src_install
- pkg_preinst
- pkg_postinst

The call order for uninstalling a package is:

- pkg_prerm
- pkg_postrm

The call order for upgrading, downgrading or reinstalling a package is:

- pkg_pretend (only for EAPIs listed in table 9.3), which is called outside of the normal call order process.
- pkg_setup
- src_unpack
- src_prepare (only for EAPIs listed in table 9.4)
- src_configure (only for EAPIs listed in table 9.5)
- src_compile
- src_test (except if RESTRICT=test)
- src_install
- pkg_preinst
- pkg_prerm for the package being replaced
- pkg_postrm for the package being replaced
- pkg_postinst

  Note: When up- or downgrading a package in EAPI 0 or 1, the last four phase functions can alternatively be called in the order pkg_preinst, pkg_postinst, pkg_prerm, pkg_postrm. This behaviour is deprecated.

The pkg_config, pkg_info and pkg_nofetch functions are not called in a normal sequence. The pkg_pretend function is called some unspecified time before a (possibly hypothetical) normal sequence.

For installing binary packages, the src phases are not called.

When building binary packages that are not to be installed locally, the pkg_preinst and pkg_postinst functions are not called.

## Chapter 10
Eclasses

Eclasses serve to store common code that is used by more than one ebuild, which greatly aids maintainability and reduces the tree size. However, due to metadata cache issues, care must be taken in their use. In format they are similar to an ebuild, and indeed are sourced as part of any ebuild using them. The interpreter is therefore the same, and the same requirements for being parseable hold.

Eclasses must be located in the eclass directory in the top level of the repository—see section 4.6. Each eclass is a single file named <name>.eclass, where <name> is the name of this eclass, used by inherit and EXPORT_FUNCTIONS among other places. <name> must be a valid eclass name, as per section 3.1.6.

### 10.1 The inherit command

An ebuild wishing to make use of an eclass does so by using the inherit command in global scope. This will cause the eclass to be sourced as part of the ebuild—any function or variable definitions in the eclass will appear as part of the ebuild, with exceptions for certain metadata variables, as described below.

The inherit command takes one or more parameters, which must be the names of eclasses (excluding the .eclass suffix and the path). For each parameter, in order, the named eclass is sourced.

Eclasses may end up being sourced multiple times.

The inherit command must also ensure that:

- The ECLASS variable is set to the name of the current eclass, when sourcing that eclass.
- Once all inheriting has been done, the INHERITED metadata variable contains the name of every eclass used, separated by whitespace.

### 10.2 Eclass-defined metadata keys

accumulate-vars The IUSE, REQUIRED_USE, DEPEND, BDEPEND, RDEPEND, PDEPEND and IDEPEND variables are handled specially when set by an eclass. They must be accumulated across eclasses, appending the value set by each eclass to the resulting value after the previous one is loaded. For EAPIs listed in table 10.1 as accumulating PROPERTIES and RESTRICT, the same is true for these variables. Then the eclass-defined value is appended to that defined by the ebuild. In the case of RDEPEND, this is done after the implicit RDEPEND rules in section 7.3.7 are applied.

Table 10.1: EAPIs accumulating PROPERTIES and RESTRICT across eclasses

EAPI | Accumulates PROPERTIES? | Accumulates RESTRICT?
0, 1, 2, 3, 4, 5, 6, 7 | No | No
8, 9 | Yes | Yes

### 10.3 EXPORT_FUNCTIONS

There is one command available in the eclass environment that is neither available nor meaningful in ebuilds—EXPORT_FUNCTIONS. This can be used to alias ebuild phase functions from the eclass so that an ebuild inherits a default definition whilst retaining the ability to override and call the eclass-defined version from it. The use of it is best illustrated by an example; this is given in listing 10.1 and is a snippet from a hypothetical foo.eclass.

Listing 10.1: EXPORT_FUNCTIONS example: foo.eclass

    foo_src_compile()
    {
        econf --enable-gerbil \
                $(use_enable fnord)
        emake gerbil || die "Couldn’t make a gerbil"
        emake || die "emake failed"
    }

    EXPORT_FUNCTIONS src_compile

This example defines an eclass src_compile function and uses EXPORT_FUNCTIONS to alias it. Then any ebuild that inherits foo.eclass will have a default src_compile defined, but should the author wish to override it he can access the function in foo.eclass by calling foo_src_compile.

EXPORT_FUNCTIONS must only be used on ebuild phase functions. The function that is aliased must be named <eclass>_<phase-function>, where <eclass> is the name of the eclass.

If EXPORT_FUNCTIONS is called multiple times for the same phase function, the last call takes precedence. Eclasses may not rely upon any particular behaviour if they inherit another eclass after calling EXPORT_FUNCTIONS.

## Chapter 11
The ebuild environment

### 11.1 Defined variables

The package manager must define the following variables. Not all variables are universally meaningful; variables that are not meaningful in a given phase or in global scope may be unset or set to any value. Ebuilds must not attempt to modify any of these variables, unless otherwise specified.

Because of their special meanings, these variables may not be preserved consistently across all phases as would normally happen due to environment saving (see section 11.2). For example, EBUILD_PHASE is different for every phase, and ROOT may have changed between the various different pkg_* phases. Ebuilds must recalculate any variable they derive from an inconsistent variable.

export-vars These variables are either exported to the environment or kept as unexported shell variables, as specified for EAPIs in table 11.1; exceptions are SYSROOT, ESYSROOT, BROOT, TMPDIR and HOME, which are always exported. In EAPIs where variables are not exported, the package manager must pass those that are required by ebuild-specific external commands (see section 12.3) in an implementation-defined manner.

Variables listed in section 5.3.2 as having specific meanings or special handling, and that are set in the active profiles’ make.defaults files, obey the same export rules specified for EAPIs in table 11.1. This behaviour is governed by the EAPI of the ebuild, not that of the profile. Except where otherwise noted, all other variables set in the active profiles’ make.defaults files must be exported to the environment.

Table 11.1: EAPIs with variables exported to the environment

EAPI | Variables exported?
0, 1, 2, 3, 4, 5, 6, 7, 8 | Yes
9 | No

Table 11.2: Defined variables
Variable | Legal in | Consistent? | Description
P | All | No1 | Package name and version, without the revision part. For example, vim-7.0.174.
PF | All | No1 | Package name, version, and revision (if any), for example vim-7.0.174-r1.
PN | All | No1 | Package name, for example vim.
CATEGORY | All | No1 | The package’s category, for example app-editors.
PV | All | Yes | Package version, with no revision. For example 7.0.174.
PR | All | Yes | Package revision, or r0 if none exists.
PVR | All | Yes | Package version and revision (if any), for example 7.0.174 or 7.0.174-r1.
A | src_*, pkg_nofetch | Yes | All source files available for the package, whitespace separated with no leading or trailing whitespace, and in the order in which the item first appears in a matched component of SRC_URI. Does not include any that are disabled because of USE conditionals. The value is calculated from the base names of each element of the SRC_URI ebuild metadata variable.
AA2 | src_*, pkg_nofetch | Yes | aa All source files that could be available for the package, including any that are disabled in A because of USE conditionals. The value is calculated from the base names of each element of the SRC_URI ebuild metadata variable. Only for EAPIs listed in table 11.4 as supporting AA.
FILESDIR | src_*, global scope3 | Yes | The full path to a directory where the files from the package’s files directory (used for small support files or patches) are available. See section 4.3. May or may not exist; if a repository provides no support files for the package in question then an ebuild must be prepared for the situation where FILESDIR points to a non-existent directory.
DISTDIR | src_*, global scope3 | Yes | The full path to the directory in which the files in the A variable are stored.
WORKDIR | src_*, global scope3 | Yes | The full path to the ebuild’s working directory, where all build data should be contained.
S | src_* | Yes | The full path to the temporary build directory, used by src_compile, src_install etc. Defaults to ${WORKDIR}/${P}. May be modified by ebuilds. If S is assigned in the global scope of an ebuild, then the restrictions of section 11.2 for global variables apply.
PORTDIR | src_* | No | portdir The full path to the master repository’s base directory. Only for EAPIs listed in table 11.4 as supporting PORTDIR.
ECLASSDIR | src_* | No | eclassdir The full path to the master repository’s eclass directory. Only for EAPIs listed in table 11.4 as supporting ECLASSDIR.
ROOT | pkg_* | No | The absolute path to the root directory into which the package is to be merged. Phases which run with full filesystem access must not touch any files outside of the directory given in ROOT. Also of note is that in a cross-compiling environment, binaries inside of ROOT will not be executable on the build machine, so ebuilds must not call them. The presence of a trailing slash is EAPI dependent as listed in table 11.8.
EROOT | pkg_* | No | Contains the concatenation of the paths in the ROOT and EPREFIX variables, for convenience. See also the EPREFIX variable. Only for EAPIs listed in table 11.5 as supporting EROOT. The presence of a trailing slash is EAPI dependent as listed in table 11.8.
SYSROOT | src_*, pkg_setup4 | No | sysroot The absolute path to the root directory containing build dependencies satisfied by DEPEND. Only for EAPIs listed in table 11.3 as supporting SYSROOT. Always exported to the environment.
ESYSROOT | src_*, pkg_setup4 | No | Contains the concatenation of the SYSROOT path and applicable prefix value, as determined by table 8.3. Only for EAPIs listed in table 11.5 as supporting ESYSROOT. Always exported to the environment.
BROOT | src_*, pkg_setup,4 pkg_preinst, pkg_postinst, pkg_prerm, pkg_postrm5 | No | broot The absolute path to the root directory containing build dependencies satisfied by BDEPEND and IDEPEND, typically executable build tools. This includes any applicable offset prefix. Only for EAPIs listed in table 11.3 as supporting BROOT. Always exported to the environment.
T | All | Partially6 | The full path to a temporary directory for use by the ebuild.
TMPDIR | All | Partially6 | Must be set to the location of a usable temporary directory, for any applications called by an ebuild. Must not be used by ebuilds directly; see T above. TMPDIR is always exported to the environment.
HOME | All | Partially6 | The full path to an appropriate temporary directory for use by any programs invoked by the ebuild that may read or modify the home directory. HOME is always exported to the environment.
EPREFIX | All | Yes | The normalised offset-prefix path of an offset installation. When EPREFIX is not set in the calling environment, EPREFIX defaults to the built-in offset-prefix that was set during installation of the package manager. When a different EPREFIX value than the built-in value is set in the calling environment, a cross-prefix build is performed where using the existing utilities, a package is built for the given EPREFIX, akin to ROOT. See also section 11.1.3. Only for EAPIs listed in table 11.5 as supporting EPREFIX.
D | src_* | Yes | Contains the full path to the image directory into which the package should be installed. Ebuilds must not attempt to access the directory in src_* phases other than src_install. The presence of a trailing slash is EAPI dependent as listed in table 11.8.
D (continued) | pkg_preinst | No7 | Contains the full path to the image directory of the package about to be merged. The presence of a trailing slash is EAPI dependent as listed in table 11.8.
ED | src_*, pkg_preinst | See D | Contains the concatenation of the paths in the D and EPREFIX variables, for convenience. See also the EPREFIX variable. Only for EAPIs listed in table 11.5 as supporting ED. Ebuilds must not attempt to access the directory in src_* phases other than src_install. The presence of a trailing slash is EAPI dependent as listed in table 11.8.
DESTTREE | src_install | No | desttree Controls the location where dobin, dolib, domo, and dosbin install things. Only for EAPIs listed in table 11.4 as supporting DESTTREE. In all other EAPIs, this is retained as a conceptual variable inaccessible from the ebuild environment.
INSDESTTREE | src_install | No | insdesttree Controls the location where doins installs things. Only for EAPIs listed in table 11.4 as supporting INSDESTTREE. In all other EAPIs, this is retained as a conceptual variable inaccessible from the ebuild environment.
USE | All | Yes | A whitespace-delimited list of all active USE flags for this ebuild. See section 11.1.1 for details.
EBUILD_PHASE | src_*, pkg_* | No | Takes one of the values config, setup, nofetch, unpack, prepare, configure, compile, test, install, preinst, postinst, prerm, postrm, info, pretend according to the top level ebuild function that was executed by the package manager. Behaviour is unspecified when the ebuild is being sourced for other (e. g. metadata or QA) purposes.
EBUILD_PHASE_FUNC | src_*, pkg_* | No | ebuild-phase-func Takes one of the values pkg_config, pkg_setup, pkg_nofetch, src_unpack, src_prepare, src_configure, src_compile, src_test, src_install, pkg_preinst, pkg_postinst, pkg_prerm, pkg_postrm, pkg_info, pkg_pretend according to the top level ebuild function that was executed by the package manager. Behaviour is unspecified when the ebuild is being sourced for other (e. g. metadata or QA) purposes. Only for EAPIs listed in table 11.3 as supporting EBUILD_PHASE_FUNC.
KV | All | Yes | kv The version of the running kernel at the time the ebuild was first executed, as returned by the uname -r command or equivalent. May be modified by ebuilds. Only for EAPIs listed in table 11.4 as supporting KV.
MERGE_TYPE | pkg_* | No | merge-type The type of package that is being merged. Possible values are: source if building and installing a package from source, binary if installing a binary package, and buildonly if building a binary package without installing it. Only for EAPIs listed in table 11.3 as supporting MERGE_TYPE.
REPLACING_VERSIONS | pkg_preinst, pkg_postinst (pkg_pretend, pkg_setup) | Yes | A list of all versions of this package (including revision, if specified), whitespace separated with no leading or trailing whitespace, that are being replaced (uninstalled or overwritten) as a result of this install. See section 11.1.2, especially for the phases in which the variable is legal. Only for EAPIs listed in table 11.3 as supporting REPLACING_VERSIONS.
REPLACED_BY_VERSION | pkg_prerm, pkg_postrm | Yes | The single version of this package (including revision, if specified) that is replacing us, if we are being uninstalled as part of an install, or an empty string otherwise. See section 11.1.2. Only for EAPIs listed in table 11.3 as supporting REPLACED_BY_VERSION.

Table 11.3: EAPIs supporting various added env variables

EAPI | MERGE_TYPE? | REPLACING_VERSIONS? | REPLACED_BY_VERSION? | EBUILD_PHASE_FUNC? | SYSROOT? | BROOT?
0, 1, 2, 3 | No | No | No | No | No | No
4 | Yes | Yes | Yes | No | No | No
5, 6 | Yes | Yes | Yes | Yes | No | No
7, 8, 9 | Yes | Yes | Yes | Yes | Yes | Yes

Table 11.4: EAPIs supporting various removed env variables

EAPI | AA? | KV? | PORTDIR? | ECLASSDIR? | DESTTREE? | INSDESTTREE?
0, 1, 2, 3 | Yes | Yes | Yes | Yes | Yes | Yes
4, 5, 6 | No | No | Yes | Yes | Yes | Yes
7, 8, 9 | No | No | No | No | No | No

Table 11.5: EAPIs supporting offset-prefix env variables

EAPI | EPREFIX? | EROOT? | ED? | ESYSROOT?
0, 1, 2 | No | No | No | No
3, 4, 5, 6 | Yes | Yes | Yes | No
7, 8, 9 | Yes | Yes | Yes | Yes

CHOST, CBUILD and CTARGET, if not set by profiles, must contain either an appropriate machine tuple (the definition of appropriate is beyond the scope of this specification) or be unset.

PATH must be initialized by the package manager to a “usable” default. The exact value here is left up to interpretation, but it should include the equivalent “sbin” and “bin” and any package manager specific directories.

GZIP, BZIP, BZIP2, CDPATH, GREP_OPTIONS, GREP_COLOR and GLOBIGNORE must not be set. env-unset In addition, any variable whose name appears in the ENV_UNSET variable must be unset, for EAPIs listed in table 5.7 as supporting ENV_UNSET.

locale-settings The package manager must ensure that the LC_CTYPE and LC_COLLATE locale categories are equivalent to the POSIX locale, as far as characters in the ASCII range (U+0000 to U+007F) are concerned. Only for EAPIs listed in such a manner in table 11.6.

Table 11.6: Locale settings for EAPIs

EAPI | Sane LC_CTYPE and LC_COLLATE?
0, 1, 2, 3, 4, 5 | Undefined
6, 7, 8, 9 | Yes

#### 11.1.1 USE and IUSE handling

This section discusses the handling of four variables:

IUSE

  is the variable calculated from the IUSE values defined in ebuilds and eclasses.

IUSE_REFERENCEABLE

  is a variable calculated from IUSE and a variety of other sources described below. It is purely a conceptual variable; it is inaccessible from the ebuild environment. Values in IUSE_REFERENCEABLE may legally be used in queries from other packages about an ebuild’s state (for example, for use dependencies).

IUSE_EFFECTIVE

  is another conceptual, inaccessible variable. Values in IUSE_EFFECTIVE are those which an ebuild may legally use in queries about itself (for example, for the use function, and for use in dependency specification conditional blocks).

USE

  is a variable calculated by the package manager and exported to the ebuild environment.

In all cases, the values of IUSE_REFERENCEABLE and IUSE_EFFECTIVE are undefined during metadata generation.

For EAPIs listed in table 5.6 as not supporting profile defined IUSE injection, IUSE_REFERENCEABLE is equal to the calculated IUSE value, and IUSE_EFFECTIVE contains the following values:

- All values in the calculated IUSE value.
- All possible values for the ARCH variable.
- All legal use flag names whose name starts with the lower-case equivalent of any value in the profile USE_EXPAND variable followed by an underscore.

profile-iuse-inject For EAPIs listed in table 5.6 as supporting profile defined IUSE injection, IUSE_REFERENCEABLE and IUSE_EFFECTIVE are equal and contain the following values:

- All values in the calculated IUSE value.
- All values in the profile IUSE_IMPLICIT variable.
- All values in the profile variable named USE_EXPAND_VALUES_${v}, where ${v} is any value in the intersection of the profile USE_EXPAND_UNPREFIXED and USE_EXPAND_IMPLICIT variables.
- All values for ${lower_v}_${x}, where ${x} is all values in the profile variable named USE_EXPAND_VALUES_${v}, where ${v} is any value in the intersection of the profile USE_EXPAND and USE_EXPAND_IMPLICIT variables and ${lower_v} is the lower-case equivalent of ${v}.

The USE variable is set by the package manager. For each value in IUSE_EFFECTIVE, USE shall contain that value if the flag is to be enabled for the ebuild in question, and shall not contain that value if it is to be disabled. In EAPIs listed in table 5.6 as not supporting profile defined IUSE injection, USE may contain other flag names that are not relevant for the ebuild.

For EAPIs listed in table 5.6 as supporting profile defined IUSE injection, the variables named in USE_EXPAND and USE_EXPAND_UNPREFIXED shall have their profile-provided values reduced to contain only those values that are present in IUSE_EFFECTIVE.

For EAPIs listed in table 5.6 as supporting profile defined IUSE injection, the package manager must save the calculated value of IUSE_EFFECTIVE when installing a package. Details are beyond the scope of this specification.

#### 11.1.2 REPLACING_VERSIONS and REPLACED_BY_VERSION

replace-version-vars In EAPIs listed in table 11.3 as supporting it, the REPLACING_VERSIONS variable shall be defined in pkg_preinst and pkg_postinst. In addition, it may be defined in pkg_pretend and pkg_setup, although ebuild authors should take care to handle binary package creation and installation correctly when using it in these phases.

REPLACING_VERSIONS is a list, not a single optional value, to handle pathological cases such as installing foo-2:2 to replace foo-2:1 and foo-3:2.

In EAPIs listed in table 11.3 as supporting it, the REPLACED_BY_VERSION variable shall be defined in pkg_prerm and pkg_postrm. It shall contain at most one value.

#### 11.1.3 Offset-prefix variables

Table 11.7: EAPIs supporting offset-prefix

EAPI | Supports offset-prefix?
0, 1, 2 | No
3, 4, 5, 6, 7, 8, 9 | Yes

offset-prefix-vars Table 11.7 lists the EAPIs which support offset-prefix installations. This support was initially added in EAPI 3, in the form of three extra variables. Two of these, EROOT and ED, are convenience variables using the variable EPREFIX. In EAPIs that do not support an offset-prefix, the installation offset is hardwired to /usr. In offset-prefix supporting EAPIs the installation offset is set as ${EPREFIX}/usr and hence can be adjusted using the variable EPREFIX. Note that the behaviour of offset-prefix aware and agnostic is the same when EPREFIX is set to the empty string in offset-prefix aware EAPIs. The latter do have the variables ED and EROOT properly set, though.

#### 11.1.4 Path variables and trailing slash

Unless specified otherwise, the paths provided through package manager variables do not end with a trailing slash. Consequently, the system root directory will be represented by the empty string. A few exceptions to this rule are listed in table 11.8 along with applicable EAPIs.

For EAPIs where those variables are defined to always end with a trailing slash, the package manager guarantees that a trailing slash will always be appended to the path in question. If the path specifies the system root directory, it will consist of a single slash (/).

trailing-slash For EAPIs where those variables are defined to never end with a trailing slash, the package manager guarantees that a trailing slash will never be present. If the path specifies the system root directory, it will be empty.

Table 11.8: Variables that always or never end with a trailing slash

EAPI | Ends with a trailing slash?
| ROOT, EROOT | D, ED
0, 1, 2, 3, 4, 5, 6 | always | always
7, 8, 9 | never | never

### 11.2 The state of variables between functions

Exported and default scope variables are saved between functions. A non-local variable set in a function earlier in the call sequence must have its value preserved for later functions, including functions executed as part of a later uninstall.

  Note: pkg_pretend is not part of the normal call sequence, and does not take part in environment saving.

The visibility of variables defined at the top level of an ebuild or eclass is unspecified. Depending on the implementation, such variables may behave as if evaluated in global scope or as if evaluated within a function body; ebuilds must not rely upon either behaviour. Consequently, at the top level, the local builtin may not be used, and the declare builtin may only be used with the -g option when defining variables.

Variables that were exported must remain exported in later functions; variables with default visibility may retain default visibility or be exported. Variables with special meanings to the package manager are excluded from this rule.

Global variables must only contain invariant values (see section 7.1). If a global variable’s value is invariant, it may have the value that would be generated at any given point in the build sequence.

This is demonstrated by code listing 11.1.

Listing 11.1: Environment state between functions

    GLOBAL_VARIABLE="a"

    src_compile()
    {
        GLOBAL_VARIABLE="b"
        DEFAULT_VARIABLE="c"
        export EXPORTED_VARIABLE="d"
        local LOCAL_VARIABLE="e"
    }

    src_install(){
        [[ ${GLOBAL_VARIABLE} == "a" ]] \
            || [[ ${GLOBAL_VARIABLE} == "b" ]] \
            || die "broken env saving for globals"

        [[ ${DEFAULT_VARIABLE} == "c" ]] \
            || die "broken env saving for default"

        [[ ${EXPORTED_VARIABLE} == "d" ]] \
            || die "broken env saving for exported"

        [[ $(printenv EXPORTED_VARIABLE ) == "d" ]] \
            || die "broken env saving for exported"

        [[ -z ${LOCAL_VARIABLE} ]] \
            || die "broken env saving for locals"
    }

### 11.3 The state of the system between functions

For the sake of this section:

- Variancy is any package manager action that modifies either ROOT or / in any way that isn’t merely a simple addition of something that doesn’t alter other packages. This includes any non-default call to any pkg phase function except pkg_setup, a merge of any package or an unmerge of any package.
- As an exception, changes to DISTDIR do not count as variancy.
- The pkg_setup function may be assumed not to introduce variancy. Thus, ebuilds must not perform variant actions in this phase.

The following exclusivity and invariancy requirements are mandated:

- No variancy shall be introduced at any point between a package’s pkg_setup being started up to the point that that package is merged, except for any variancy introduced by that package.
- There must be no variancy between a package’s pkg_setup and a package’s pkg_postinst, except for any variancy introduced by that package.
- Any non-default pkg phase function must be run exclusively.
- Each phase function must be called at most once during the build process for any given package.

## Chapter 12
Available commands

This chapter documents the commands available to an ebuild. Unless otherwise specified, they may be aliases, shell functions, or executables in the ebuild’s PATH.

When an ebuild is being sourced for metadata querying rather than for a build (that is to say, when none of the src_ or pkg_ functions are to be called), no external command may be executed. The package manager may take steps to enforce this.

### 12.1 System commands

Any ebuild not listed in the system set for the active profile(s) may assume the presence of every command that is always provided by the system set for that profile. However, it must target the lowest common denominator of all systems on which it might be installed—in most cases this means that the only packages that can be assumed to be present are those listed in the base profile or equivalent, which is inherited by all available profiles. If an ebuild requires any applications not provided by the system profile, or that are provided conditionally based on USE flags, appropriate dependencies must be used to ensure their presence.

#### 12.1.1 Guaranteed system commands

The following commands must always be available in the ebuild environment:

- All builtin commands in GNU bash, version as listed in table 6.1.
- sed must be available, and must support all forms of invocations valid for GNU sed version 4 or later.
- gnu-patch patch must be available, and must support all inputs valid for GNU patch, version as listed in table 12.1.
- gnu-find find and xargs must be available, and must support all forms of invocations valid for GNU findutils version 4.4 or later. Only for EAPIs listed in table 12.1 as requiring GNU find.

Table 12.1: System commands for EAPIs

EAPI | GNU find? | GNU patch version
0, 1, 2, 3, 4 | Undefined | Any
5, 6 | Yes | Any
7, 8, 9 | Yes | 2.7

### 12.2 Commands provided by package dependencies

In some cases a package’s build process will require the availability of executables not provided by the core system, a common example being autotools. The availability of commands provided by the particular types of dependencies is explained in section 8.1.

### 12.3 Ebuild-specific commands

The following commands will always be available in the ebuild environment, provided by the package manager. Except where otherwise noted, they may be internal (shell functions or aliases) or external commands available in PATH; where this is not specified, ebuilds may not rely upon either behaviour. Unless otherwise specified, it is an error if an ebuild calls any of these commands in global scope.

Unless otherwise noted, any output of these commands ends with a newline.

#### 12.3.1 Failure behaviour and related commands

die-on-failure Where a command is listed as having EAPI dependent failure behaviour, a failure shall either result in a non-zero exit status or abort the build process, as determined by table 12.2.

The following commands affect this behaviour:

nonfatal

  nonfatal Takes one or more arguments and executes them as a command, preserving the exit status. If this results in a command being called that would normally abort the build process due to a failure, instead a non-zero exit status shall be returned. Only in EAPIs listed in table 12.2 as supporting nonfatal.

  In EAPIs listed in table 12.2 as having nonfatal defined both as a shell function and as an external command, the package manager must provide both implementations to account for calling directly in ebuild scope or through xargs.

  Explicit die or assert commands only respect nonfatal when called with the -n option and in EAPIs supporting this option, see table 12.6.

Table 12.2: EAPI command failure behaviour

EAPI | Command failure behaviour | Supports nonfatal? | nonfatal is both a function and an external command?
0, 1, 2, 3 | Non-zero exit | No | n/a
4, 5, 6 | Aborts | Yes | No
7, 8, 9 | Aborts | Yes | Yes

#### 12.3.2 Banned commands

banned-commands Some commands are banned in some EAPIs. If a banned command is called, the package manager must abort the build process indicating an error.

Table 12.3: Banned commands

EAPI | Command banned?
| dohard | dosed | einstall | dohtml | dolib | libopts
0, 1, 2, 3 | No | No | No | No | No | No
4, 5 | Yes | Yes | No | No | No | No
6 | Yes | Yes | Yes | No | No | No
7, 8, 9 | Yes | Yes | Yes | Yes | Yes | Yes
EAPI | Command banned?
| useq | hasv | hasq | assert | domo |
0, 1, 2, 3, 4, 5, 6, 7 | No | No | No | No | No |
8 | Yes | Yes | Yes | No | No |
9 | Yes | Yes | Yes | Yes | Yes |

#### 12.3.3 Sandbox commands

These commands affect the behaviour of the sandbox. Each command takes a single path as argument. Ebuilds must not run any of these commands once the current phase function has returned.

addread

  Add a path to the permitted read list.

addwrite

  Add a path to the permitted write list.

addpredict

  Add a path to the predict list. Any write to a location in this list will be denied, but will not trigger access violation messages or abort the build process.

adddeny

  Add a path to the deny list.

#### 12.3.4 Package manager query commands

These commands are used to extract information about the system. Ebuilds must not run any of these commands in parallel with any other package manager command. Ebuilds must not run any of these commands once the current phase function has returned.

pm-query-options In EAPIs listed in table 12.4 as supporting option --host-root, this flag as the first argument will cause the query to apply to the host root. Otherwise, it applies to ROOT.

In EAPIs listed in table 12.4 as supporting options -b, -d and -r, these mutually exclusive flags as the first argument will cause the query to apply to locations targetted by BDEPEND, DEPEND and RDEPEND, respectively. When none of these options are given, -r is assumed.

has_version

  Takes exactly one package dependency specification as an argument. Returns true if a package matching the specification is installed, and false otherwise.

best_version

  Takes exactly one package dependency specification as an argument. If a matching package is installed, prints category/package-version of the highest matching version; otherwise, prints an empty string. The exit code is unspecified.

Table 12.4: Package manager query command options supported by EAPIs

EAPI | --host-root? | -b? | -d? | -r?
0, 1, 2, 3, 4 | No | No | No | No
5, 6 | Yes | No | No | No
7, 8, 9 | No | Yes | Yes | Yes

#### 12.3.5 Output commands

These commands display messages to the user. Unless otherwise stated, the entire argument list is used as a message, with backslash-escaped characters interpreted as for the echo -e command of bash, notably \t for a horizontal tab, \n for a new line, and \\ for a literal backslash. These commands must be implemented internally as shell functions and may be called in global scope. Ebuilds must not run any of these commands once the current phase function has returned.

output-no-stdout Unless otherwise noted, output may be sent to stderr or some other appropriate facility. In EAPIs listed in table 12.5 as not allowing stdout output, using stdout as an output facility is forbidden.

einfo

  Displays an informational message.

einfon

  Displays an informational message without a trailing newline.

elog

  Displays an informational message of slightly higher importance. The package manager may choose to log elog messages by default where einfo messages are not, for example.

ewarn

  Displays a warning message. Must not go to stdout.

eqawarn

  eqawarn Display a QA warning message intended for ebuild developers. The package manager may provide appropriate mechanisms to skip those messages for normal users. Must not go to stdout. Only available in EAPIs listed in table 12.5 as supporting eqawarn.

eerror

  Displays an error message. Must not go to stdout.

ebegin

  Displays an informational message. Should be used when beginning a possibly lengthy process, and followed by a call to eend.

eend

  Indicates that the process begun with an ebegin message has completed. Takes one fixed argument, which is a numeric return code, and an optional message in all subsequent arguments. If the first argument is 0, prints a success indicator; otherwise, prints the message followed by a failure indicator. Returns its first argument as exit status.

Table 12.5: Output commands for EAPIs

EAPI | Commands can output to stdout? | Supports eqawarn?
0, 1, 2, 3, 4, 5, 6 | Yes | No
7, 8, 9 | No | Yes

#### 12.3.6 Error commands

These commands are used when an error is detected that will prevent the build process from completing. Ebuilds must not run any of these commands once the current phase function has returned.

die

  nonfatal-die If called under the nonfatal command (as per section 12.3.1) and with -n as its first parameter, displays a failure message provided in its following argument and then returns a non-zero exit status. Only in EAPIs listed in table 12.6 as supporting option -n. Otherwise, displays a failure message provided in its first and only argument, and then aborts the build process.

  subshell-die In EAPIs listed in table 12.6 as not providing subshell support, die is not guaranteed to work correctly if called from a subshell environment.

assert

  Checks the shell’s pipe status array, and if any element is non-zero (indicating failure), calls die, passing any parameters to it. In EAPIs listed in table 12.3, this command is banned as per section 12.3.2.

pipestatus

  pipestatus Checks the shell’s pipe status array, i. e. the exit status of the command(s) in the most recently executed foreground pipeline. Returns shell true (0) if all elements are zero, or the last non-zero element otherwise. If called with -v as the first argument, also outputs the pipe status array as a space-separated list. Only available in EAPIs listed in table 12.7 as supporting pipestatus.

Table 12.6: Properties of die command in EAPIs

EAPI | Supports die -n? | die works in subshell?
0, 1, 2, 3, 4, 5 | No | No
6 | Yes | No
7, 8, 9 | Yes | Yes

Table 12.7: EAPIs supporting pipestatus

EAPI | Supports pipestatus?
0, 1, 2, 3, 4, 5, 6, 7, 8 | No
9 | Yes

#### 12.3.7 Patch commands

These commands are used during the src_prepare phase to apply patches to the package’s sources. Ebuilds must not run any of these commands once the current phase function has returned.

eapply

  eapply Takes zero or more GNU patch options, followed by one or more file or directory paths. Processes options and applies all patches found in specified locations according to algorithm 12.1. If applying the patches fails, it aborts the build using die, unless run using nonfatal, in which case it returns non-zero exit status. Only available in EAPIs listed in table 12.8 as supporting eapply.

  Algorithm 12.1: eapply logic
  1: if any parameter is equal to "--" then
  2: collect all parameters before the first "--" in the options array
  3: collect all parameters after the first "--" in the files array
  4: else if any parameter that begins with a hyphen follows one that does not then
  5: abort the build process with an error
  6: else
  7: collect all parameters beginning with a hyphen in the options array
  8: collect all remaining parameters in the files array
  9: end if
  10: if the files array is empty then
  11: abort the build process with an error
  12: end if
  13: for all x in the files array do
  14: if $x is a directory then
  15: if not any files match $x/*.diff or $x/*.patch then
  16: abort the build process with an error
  17: end if
  18: for all files f matching $x/*.diff or $x/*.patch, sorted in POSIX locale do
  19: call patch -p1 -f -g0 --no-backup-if-mismatch "${options[@]}" < "$f"
  20: if child process returned with non-zero exit status then
  21: return immediately with that status
  22: end if
  23: end for
  24: else
  25: call patch -p1 -f -g0 --no-backup-if-mismatch "${options[@]}" < "$x"
  26: if child process returned with non-zero exit status then
  27: return immediately with that status
  28: end if
  29: end if
  30: end for
  31: return shell true (0)

eapply_user

  eapply-user Takes no arguments. Package managers supporting it apply user-provided patches to the source tree in the current working directory. Exact behaviour is implementation defined and beyond the scope of this specification. Package managers not supporting it must implement the command as a no-op. Returns shell true (0) if patches applied successfully, or if no patches were provided. Otherwise, aborts the build process, unless run using nonfatal, in which case it returns non-zero exit status. Only available in EAPIs listed in table 12.8 as supporting eapply_user. In EAPIs where it is supported, eapply_user must be called once in the src_prepare phase. For any subsequent calls, the command will do nothing and return 0.

Table 12.8: Patch commands for EAPIs

EAPI | eapply? | eapply_user?
0, 1, 2, 3, 4, 5 | No | No
6, 7, 8, 9 | Yes | Yes

#### 12.3.8 Build commands

These commands are used during the src_configure, src_compile, src_test, and src_install phases to run the package’s build commands. Ebuilds must not run any of these commands once the current phase function has returned.

econf

  Calls the program’s ./configure script. This is designed to work with GNU Autoconf-generated scripts. Any additional parameters passed to econf are passed directly to ./configure, after the default options below. econf will look in the current working directory for a configure script unless the ECONF_SOURCE environment variable is set, in which case it is taken to be the directory containing it.

  econf-options econf must pass the following options to the configure script:

  - --prefix must default to ${EPREFIX}/usr unless overridden by econf’s caller.
  - --mandir must be ${EPREFIX}/usr/share/man
  - --infodir must be ${EPREFIX}/usr/share/info
  - --datadir must be ${EPREFIX}/usr/share
  - --datarootdir must be ${EPREFIX}/usr/share, if the EAPI is listed in table 12.9 as using it. This option will only be passed if the string --datarootdir occurs in the output of configure --help.
  - --sysconfdir must be ${EPREFIX}/etc
  - --localstatedir must be ${EPREFIX}/var/lib
  - --docdir must be ${EPREFIX}/usr/share/doc/${PF}, if the EAPI is listed in table 12.9 as using it. This option will only be passed if the string --docdir occurs in the output of configure --help.
  - --htmldir must be ${EPREFIX}/usr/share/doc/${PF}/html, if the EAPI is listed in table 12.9 as using it. This option will only be passed if the string --htmldir occurs in the output of configure --help.
  - --with-sysroot must be ${ESYSROOT:-/}, if the EAPI is listed in table 12.9 as using it. This option will only be passed if the string --with-sysroot occurs in the output of configure --help.
  - --build must be the value of the CBUILD environment variable. This option will only be passed if CBUILD is non-empty.
  - --host must be the value of the CHOST environment variable.
  - --target must be the value of the CTARGET environment variable. This option will only be passed if CTARGET is non-empty.
  - --libdir must be set according to algorithm 12.2.
  - --disable-dependency-tracking, if the EAPI is listed in table 12.9 as using it. This option will only be passed if the string --disable-dependency-tracking occurs in the output of configure --help.
  - --disable-silent-rules, if the EAPI is listed in table 12.9 as using it. This option will only be passed if the string --disable-silent-rules occurs in the output of configure --help.
  - --disable-static, if the EAPI is listed in table 12.9 as using it. This option will only be passed if both strings --enable-static and --enable-shared occur in the output of configure --help.

  For the option names beginning with with-, disable- or enable-, a string in configure --help output matches only if it is not immediately followed by any of the characters [A-Za-z0-9+_.-].

  Table 12.9: Extra econf arguments for EAPIs

  EAPI | --datarootdir | --docdir | --htmldir | --with-sysroot
  0, 1, 2, 3, 4, 5 | No | No | No | No
  6 | No | Yes | Yes | No
  7 | No | Yes | Yes | Yes
  8, 9 | Yes | Yes | Yes | Yes
  EAPI | --disable-dependency-tracking | --disable-silent-rules | --disable-static |
  0, 1, 2, 3 | No | No | No |
  4 | Yes | No | No |
  5, 6, 7 | Yes | Yes | No |
  8, 9 | Yes | Yes | Yes |

  Note that the ${EPREFIX} component represents the same offset-prefix as described in table 11.2. It facilitates offset-prefix installations which is supported by EAPIs listed in table 11.5. When no offset-prefix installation is in effect, EPREFIX becomes the empty string, making the behaviour of econf equal for both offset-prefix supporting and agnostic EAPIs.

  econf must be implemented internally—that is, as a bash function and not an external script. Should any portion of it fail, it must abort the build using die, unless run using nonfatal, in which case it must return non-zero exit status.

  Algorithm 12.2: econf --libdir logic
  1: let prefix=${EPREFIX}/usr
  2: if the caller specified --exec-prefix=$ep then
  3: let prefix=$ep
  4: else if the caller specified --prefix=$p then
  5: let prefix=$p
  6: end if
  7: let libdir=
  8: if the ABI environment variable is set then
  9: let libvar=LIBDIR_$ABI
  10: if the environment variable named by libvar is set then
  11: let libdir=the value of the variable named by libvar
  12: end if
  13: end if
  14: if libdir is non-empty then
  15: pass --libdir=$prefix/$libdir to configure
  16: end if

emake

  Calls the ${MAKE} program, or GNU make if the MAKE variable is unset. Any arguments given are passed directly to the make command, as are the user’s chosen MAKEOPTS. Arguments given to emake override user configuration. See also section 12.1.1. emake must be an external program and cannot be a function or alias—it must be callable from e. g. xargs. Failure behaviour is EAPI dependent as per section 12.3.1.

einstall

  A shortcut for the command given in listing 12.1. Any arguments given to einstall are passed verbatim to emake, as shown. Failure behaviour is EAPI dependent as per section 12.3.1. In EAPIs listed in table 12.3, this command is banned as per section 12.3.2.

  The variable ED is defined as in table 11.2 and depends on the use of an offset-prefix. When such offset-prefix is absent, ED is equivalent to D. ED is always available in EAPIs that support offset-prefix installations as listed in table 11.5, hence EAPIs lacking offset-prefix support should use D instead of ED in the command given in listing 12.1. Variable libdir is an auxiliary local variable whose value is determined by algorithm 12.4.

  Listing 12.1: einstall command

      emake \
          prefix="${ED}"/usr \
          datadir="${ED}"/usr/share \
          mandir="${ED}"/usr/share/man \
          infodir="${ED}"/usr/share/info \
          libdir="${ED}"/usr/${libdir} \
          localstatedir="${ED}"/var/lib \
          sysconfdir="${ED}"/etc \
          -j1 \
          "$@" \
          install

#### 12.3.9 Installation commands

These commands are used to install files into the staging area, in cases where the package’s make install target cannot be used or does not install all needed files. Except where otherwise stated, all filenames created or modified are relative to the staging directory including the offset-prefix ED in offset-prefix aware EAPIs, or just the staging directory D in offset-prefix agnostic EAPIs. Existing destination files are overwritten. These commands must all be external programs and not bash functions or aliases—that is, they must be callable from xargs. Calling any of these commands without a filename parameter is an error. Ebuilds must not run any of these commands once the current phase function has returned.

dobin

  Installs the given files into DESTTREE/bin, where DESTTREE defaults to /usr. Gives the files mode 0755 and transfers file ownership to the superuser or its equivalent on the system or installation at hand. In a non-offset-prefix installation this ownership is 0:0, while in an offset-prefix aware installation this may be e. g. joe:users. Failure behaviour is EAPI dependent as per section 12.3.1.

doconfd

  Installs the given config files into /etc/conf.d/, by default with file mode 0644. For EAPIs listed in table 12.17 as respecting insopts in doconfd, the install options set by the most recent insopts call override the default. Failure behaviour is EAPI dependent as per section 12.3.1.

dodir

  Creates the given directories, by default with file mode 0755, or with the install options set by the most recent diropts call. Failure behaviour is EAPI dependent as per section 12.3.1.

dodoc

  dodoc Installs the given files into a subdirectory under /usr/share/doc/${PF}/ with file mode 0644. The subdirectory is set by the most recent call to docinto. If docinto has not yet been called, instead installs to the directory /usr/share/doc/${PF}/. For EAPIs listed in table 12.10 as supporting -r, if the first argument is -r, any subsequent arguments that are directories are installed recursively to the appropriate location; in any other case, it is an error for a directory to be specified. Any directories that don’t already exist are created using install -d with no additional options. Failure behaviour is EAPI dependent as per section 12.3.1.

doenvd

  Installs the given environment files into /etc/env.d/, by default with file mode 0644. For EAPIs listed in table 12.17 as respecting insopts in doenvd, the install options set by the most recent insopts call override the default. Failure behaviour is EAPI dependent as per section 12.3.1.

doexe

  Installs the given files into the directory specified by the most recent exeinto call. If exeinto has not yet been called, behaviour is undefined. Files are installed by default with file mode 0755, or with the install options set by the most recent exeopts call. Failure behaviour is EAPI dependent as per section 12.3.1.

dohard

  Takes two parameters. Creates a hardlink from the second to the first. Both paths are relative to the staging directory including the offset-prefix ED in offset-prefix aware EAPIs, or just the staging directory D in offset-prefix agnostic EAPIs. In EAPIs listed in table 12.3, this command is banned as per section 12.3.2.

doheader

  doheader Installs the given header files into /usr/include/, by default with file mode 0644. For EAPIs listed in table 12.17 as respecting insopts in doheader, the install options set by the most recent insopts call override the default. If the first argument is -r, then operates recursively, descending into any directories given. Only available in EAPIs listed in table 12.11 as supporting doheader. Failure behaviour is EAPI dependent as per section 12.3.1.

dohtml

  Installs the given HTML files into a subdirectory under /usr/share/doc/${PF}/. The subdirectory is html by default, but this can be overridden with the docinto function. Files to be installed automatically are determined by extension and the default extensions are css, gif, htm, html, jpeg, jpg, js and png. These default extensions can be extended or reduced (see below). The options that can be passed to dohtml are as follows:

  -r
    enables recursion into directories.
  -V
    enables verbosity.
  -A
    adds file type extensions to the default list.
  -a
    sets file type extensions to only those specified.
  -f
    list of files that are able to be installed.
  -x
    list of directories that files will not be installed from (only used in conjunction with -r).
  -p
    sets a document prefix for installed files, not to be confused with the global offset-prefix.

  In EAPIs listed in table 12.3, this command is banned as per section 12.3.2. Failure behaviour is EAPI dependent as per section 12.3.1.

  It is undefined whether a failure shall occur if -r is not specified and a directory is encountered. Ebuilds must not rely upon any particular behaviour.

doinfo

  Installs the given GNU Info files into the /usr/share/info area with file mode 0644. Failure behaviour is EAPI dependent as per section 12.3.1.

doinitd

  Installs the given initscript files into /etc/init.d, by default with file mode 0755. For EAPIs listed in table 12.17 as respecting insopts in doinitd, the install options set by the most recent exeopts call override the default. Failure behaviour is EAPI dependent as per section 12.3.1.

doins

  doins Takes one or more files as arguments and installs them into INSDESTTREE, by default with file mode 0644, or with the install options set by the most recent insopts call. If the first argument is -r, then operates recursively, descending into any directories given. Any directories are created as if dodir was called. For EAPIs listed in table 12.12, doins must install symlinks as symlinks; for other EAPIs, behaviour is undefined if any symlink is encountered. Failure behaviour is EAPI dependent as per section 12.3.1.

dolib.a

  For each argument, installs it into the appropriate library subdirectory under DESTTREE, as determined by algorithm 12.4. Files are installed with file mode 0644. Any symlinks are installed into the same directory as relative links to their original target. Failure behaviour is EAPI dependent as per section 12.3.1.

dolib.so

  As for dolib.a except each file is installed with mode 0755.

dolib

  As for dolib.a except that the default install mode can be overriden with the install options set by the most recent libopts call. In EAPIs listed in table 12.3, this command is banned as per section 12.3.2.

doman

  Installs the given man pages into the appropriate subdirectory of /usr/share/man depending upon its apparent section suffix (e. g. foo.1 goes to /usr/share/man/man1/foo.1) with file mode 0644.

  doman-langs In EAPIs listed in table 12.13 as supporting language detection by filename, a man page with name of the form foo.lang.1 shall go to /usr/share/man/lang/man1/foo.1, where lang refers to a pair of lower-case ASCII letters optionally followed by an underscore and a pair of upper-case ASCII letters. Failure behaviour is EAPI dependent as per section 12.3.1.

  With option -i18n=lang, a man page shall be installed into an appropriate subdirectory of /usr/share/man/lang (e. g. /usr/share/man/lang/man1/foo.pl.1 would be the destination for foo.pl.1). The lang subdirectory level is skipped if lang is the empty string. In EAPIs specified by table 12.13, the -i18n option takes precedence over the language code in the filename.

domo

  domo-path Installs the given .mo files with file mode 0644 into the appropriate subdirectory of the locale tree, generated by taking the basename of the file, removing the .* suffix, and appending /LC_MESSAGES. The name of the installed files is the package name with .mo appended. Failure behaviour is EAPI dependent as per section 12.3.1. The locale tree location is EAPI dependent as per table 12.15. In EAPIs listed in table 12.3, this command is banned as per section 12.3.2.

dosbin

  As dobin, but installs to DESTTREE/sbin.

dosym

  Creates a symbolic link named as for its second parameter, pointing to the first. If the directory containing the new link does not exist, creates it.

  dosym-relative In EAPIs listed in table 12.16 as supporting creation of relative paths, when called with option -r, the first parameter (the link target) is converted from an absolute path to a path relative to the the second parameter (the link name). The algorithm must return a result identical to the one returned by the function in listing 12.2, with realpath and dirname from GNU coreutils version 8.32. Specifying option -r together with a relative path as first (target) parameter is an error.

  Failure behaviour is EAPI dependent as per section 12.3.1.

  Listing 12.2: Create a relative path for dosym -r

      dosym_relative_path() {
          local link=$(realpath -m -s "/${2#/}")
          local linkdir=$(dirname "${link}")
          realpath -m -s --relative-to="${linkdir}" "$1"
      }

fowners

  Acts as for chown, but takes paths relative to the image directory. Failure behaviour is EAPI dependent as per section 12.3.1.

fperms

  Acts as for chmod, but takes paths relative to the image directory. Failure behaviour is EAPI dependent as per section 12.3.1.

keepdir

  For each argument, creates a directory as for dodir, and an empty file whose name starts with .keep in that directory to ensure that the directory does not get removed by the package manager should it be empty at any point. Failure behaviour is EAPI dependent as per section 12.3.1.

newbin

  newfoo-stdin As for dobin, but takes two parameters. The first is the file to install; the second is the new filename under which it will be installed. In EAPIs specified by table 12.14, standard input is read when the first parameter is - (a hyphen). In this case, it is an error if standard input is a terminal.

newconfd

  As for doconfd, but takes two parameters as for newbin.

newdoc

  As above, for dodoc.

newenvd

  As above, for doenvd.

newexe

  As above, for doexe.

newheader

  As above, for doheader.

newinitd

  As above, for doinitd.

newins

  As above, for doins.

newlib.a

  As above, for dolib.a.

newlib.so

  As above, for dolib.so.

newman

  As above, for doman.

newsbin

  As above, for dosbin.

Table 12.10: EAPIs supporting dodoc -r

EAPI | Supports dodoc -r?
0, 1, 2, 3 | No
4, 5, 6, 7, 8, 9 | Yes

Table 12.11: EAPIs supporting doheader and newheader

EAPI | Supports doheader and newheader?
0, 1, 2, 3, 4 | No
5, 6, 7, 8, 9 | Yes

Table 12.12: EAPIs supporting symlinks for doins

EAPI | doins supports symlinks?
0, 1, 2, 3 | No
4, 5, 6, 7, 8, 9 | Yes

Table 12.13: doman language support options for EAPIs

EAPI | Language detection by filename? | Option -i18n takes precedence?
0, 1 | No | Not applicable
2, 3 | Yes | No
4, 5, 6, 7, 8, 9 | Yes | Yes

Table 12.14: EAPIs supporting stdin for new* commands

EAPI | new* can read from stdin?
0, 1, 2, 3, 4 | No
5, 6, 7, 8, 9 | Yes

Table 12.15: domo destination path in EAPIs

EAPI | Destination path
0, 1, 2, 3, 4, 5, 6 | ${DESTTREE}/share/locale
7, 8, 9 | /usr/share/locale

Table 12.16: EAPIs supporting dosym -r

EAPI | dosym supports creation of relative paths?
0, 1, 2, 3, 4, 5, 6, 7 | No
8, 9 | Yes

#### 12.3.10 Commands affecting install destinations

The following commands are used to set the various destination trees and options used by the above installation commands. They must be shell functions or aliases, due to the need to set variables read by the above commands. Ebuilds must not run any of these commands once the current phase function has returned.

into

  Takes exactly one argument, and sets the value of DESTTREE for future invocations of the above utilities to it. Creates the directory under ${ED} in offset-prefix aware EAPIs or under ${D} in offset-prefix agnostic EAPIs, using install -d with no additional options, if it does not already exist. Failure behaviour is EAPI dependent as per section 12.3.1.

insinto

  As into, for INSDESTTREE.

exeinto

  As into, for install path of doexe and newexe.

docinto

  As into, for install subdirectory of dodoc et al.

insopts

  insopts Takes one or more arguments, and sets the options passed by doins et al. to the install command to them. Behaviour upon encountering empty arguments is undefined. Depending on EAPI, affects only those commands that are specified by table 12.17 as respecting insopts.

diropts

  As insopts, for dodir et al.

exeopts

  exeopts As insopts, for doexe et al. Depending on EAPI, affects only those commands that are specified by table 12.18 as respecting exeopts.

libopts

  As insopts, for dolib et al. In EAPIs listed in table 12.3, this command is banned as per section 12.3.2.

Table 12.17: Commands respecting insopts for EAPIs

EAPI | doins? | doconfd? | doenvd? | doheader?
0, 1, 2, 3, 4, 5, 6, 7 | Yes | Yes | Yes | Yes
8, 9 | Yes | No | No | No

Table 12.18: Commands respecting exeopts for EAPIs

EAPI | doexe? | doinitd?
0, 1, 2, 3, 4, 5, 6, 7 | Yes | Yes
8, 9 | Yes | No

#### 12.3.11 Commands controlling manipulation of files in the staging area

These commands are used to control optional manipulations that the package manager may perform on files in the staging directory ED, like compressing files or stripping symbols from object files.

For each of the operations mentioned below, the package manager shall maintain an inclusion list and an exclusion list, in order to control which directories and files the operation may or may not be performed upon. The initial contents of the two lists is specified below for each of the commands, respectively.

Any of these operations shall be carried out after src_install has completed, and before the execution of any subsequent phase function. For each item in the inclusion list, pretend it has the value of the ED variable prepended, then:

- If it is a directory, act as if every file or directory immediately under this directory were in the inclusion list.
- If the item is a file, the operation may be performed on it, unless it has been excluded as described below.
- If the item does not exist, it is ignored.

Whether an item is to be excluded is determined as follows: For each item in the exclusion list, pretend it has the value of the ED variable prepended, then:

- If it is a directory, act as if every file or directory immediately under this directory were in the exclusion list.
- If the item is a file, the operation shall not be performed on it.
- If the item does not exist, it is ignored.

The package manager shall take appropriate steps to ensure that any operations that it performs on files in the staging area behave sensibly even if an item is listed in the inclusion list multiple times or if an item is a symlink.

docompress In EAPIs listed in table 12.19 as supporting controllable compression, the package manager may optionally compress a subset of the files under the ED directory. The package manager shall ensure that its compression mechanisms do not compress a file twice if it is already compressed using the same compressed file format. For compression, the initial values of the two lists are as follows:

- The inclusion list contains /usr/share/doc, /usr/share/info and /usr/share/man.
- The exclusion list contains /usr/share/doc/${PF}/html.

dostrip In EAPIs listed in table 12.19 as supporting controllable stripping of symbols, the package manager may strip a subset of the files under the ED directory. For stripping of symbols, the initial values of the two lists are as follows:

- If the RESTRICT variable described in section 7.3.6 enables a strip token, the inclusion list is empty; otherwise it contains / (the root path).
- The exclusion list is empty.

The following commands may be used in src_install to alter these lists. It is an error to call any of these functions from any other phase.

docompress

  If the first argument is -x, add each of its subsequent arguments to the exclusion list for compression. Otherwise, add each argument to the respective inclusion list. Only available in EAPIs listed in table 12.19 as supporting docompress.

dostrip

  If the first argument is -x, add each of its subsequent arguments to the exclusion list for stripping of symbols. Otherwise, add each argument to the respective inclusion list. Only available in EAPIs listed in table 12.19 as supporting dostrip.

Table 12.19: Commands controlling manipulation of files in the staging area in EAPIs

EAPI | Supports controllable compression and docompress? | Supports controllable stripping and dostrip?
0, 1, 2, 3 | No | No
4, 5, 6 | Yes | No
7, 8, 9 | Yes | Yes

#### 12.3.12 USE list functions

These functions provide behaviour based upon set or unset use flags. Ebuilds must not run any of these commands once the current phase function has returned.

Unless otherwise noted, if any of these functions is called with a flag value that is not included in IUSE_EFFECTIVE, either behaviour is undefined or it is an error as decided by table 12.20.

use

  Returns shell true (0) if the first argument (a USE flag name) is enabled, false otherwise. If the flag name is prefixed with !, returns true if the flag is disabled, and false if it is enabled. It is guaranteed that this command is quiet.

usev

  usev The same as use, but also prints the flag name if the condition is met. In EAPIs listed in table 12.21 as supporting an optional second argument for usev, prints the second argument instead, if it is specified and if the condition is met.

useq

  Deprecated synonym for use. In EAPIs listed in table 12.3, this command is banned as per section 12.3.2.

use_with

  use-with Has one-, two-, and three-argument forms. The first argument is a USE flag name, the second a configure option name (${opt}), defaulting to the same as the first argument if not provided, and the third is a string value (${value}). For EAPIs listed in table 12.21 as not supporting it, an empty third argument is treated as if it weren’t provided. If the USE flag is set, outputs --with-${opt}=${value} if the third argument was provided, and --with-${opt} otherwise. If the flag is not set, then it outputs --without-${opt}. The condition is inverted if the flag name is prefixed with !; this is valid only for the two- and three-argument forms.

use_enable

  Works the same as use_with(), but outputs --enable- or --disable- instead of --with- or --without-.

usex

  usex Accepts at least one and at most five arguments. The first argument is a USE flag name, any subsequent arguments (${arg2} to ${arg5}) are string values. If not provided, ${arg2} and ${arg3} default to yes and no, respectively; ${arg4} and ${arg5} default to the empty string. If the USE flag is set, outputs ${arg2}${arg4}. Otherwise, outputs ${arg3}${arg5}. The condition is inverted if the flag name is prefixed with !. Only available in EAPIs listed in table 12.22 as supporting usex.

in_iuse

  in-iuse Returns shell true (0) if the first argument (a USE flag name) is included in IUSE_EFFECTIVE, false otherwise. Only available in EAPIs listed in table 12.22 as supporting in_iuse.

Table 12.20: EAPI behaviour for use queries not in IUSE_EFFECTIVE

EAPI | Behaviour
0, 1, 2, 3 | Undefined
4, 5, 6, 7, 8, 9 | Error

Table 12.21: usev, use_with and use_enable arguments for EAPIs

EAPI | usev has optional second argument? | use_with and use_enable support empty third argument?
0, 1, 2, 3 | No | No
4, 5, 6, 7 | No | Yes
8, 9 | Yes | Yes

Table 12.22: EAPIs supporting usex and in_iuse

EAPI | usex? | in_iuse?
0, 1, 2, 3, 4 | No | No
5 | Yes | No
6, 7, 8, 9 | Yes | Yes

#### 12.3.13 Text list functions

These functions check a list of arguments for a particular value. They must be implemented internally as shell functions and may be called in global scope.

has

  Returns shell true (0) if the first argument (a word) is found in the list of subsequent arguments, false otherwise. Guaranteed quiet.

hasv

  The same as has, but also prints the first argument if found. In EAPIs listed in table 12.3, this command is banned as per section 12.3.2.

hasq

  Deprecated synonym for has. In EAPIs listed in table 12.3, this command is banned as per section 12.3.2.

#### 12.3.14 Version manipulation and comparison commands

ver-commands These commands provide utilities for working with version strings. They must all be implemented internally as shell functions, i. e. they are callable in global scope. Availability of these commands per EAPI is listed in table 12.23.

For the purpose of version manipulation commands, the specification provides a method for splitting an arbitrary version string (not necessarily conforming to section 3.2) into a series of version components and version separators.

In the context of this section, a version component consists either purely of digits ([0-9]+) or purely of upper- and lower-case ASCII letters ([A-Za-z]+). A version separator is either a string of any other characters ([^A-Za-z0-9]+), or it occurs at the transition between a sequence of digits and a sequence of letters, or vice versa. In the latter case, the version separator is an empty string.

The version string is processed left-to-right, with the successive version components being assigned successive indices starting with 1. The separator following a version component is assigned the index of the preceding version component. If the first version component is preceded by a non-empty string of version separator characters, this separator is assigned the index 0.

The version components are presumed present if not empty. The version separators between version components are always presumed present, even if they are empty. The version separators preceding the first version component and following the last are only presumed present if they are not empty.

Whenever the commands support ranges, the range is specified as an unsigned integer, optionally followed by a hyphen (-), which in turn is optionally followed by another unsigned integer.

A single integer specifies a single component or separator index. An integer followed by a hyphen specifies all components or separators starting with the one at the specified index. Two integers separated by a hyphen specify a range starting at the index specified by the first and ending at the second, inclusively.

ver_cut

  Takes a range as the first argument, and optionally a version string as the second. Prints a substring of the version string starting at the version component specified as start of the range and ending at the version component specified as end of the range. If the version string is not specified, ${PV} is used.

  If the range spans outside the present version components, the missing components and separators are presumed empty. In particular, the range starting at zero includes the zeroth version separator if present, and the range spanning past the last version component includes the suffix following it if present. A range that does not intersect with any present version components yields an empty string.

ver_rs

  Takes one or more pairs of arguments, optionally followed by a version string. Every argument pair specifies a range and a replacement string. Prints a version string after performing the specified separator substitutions. If the version string is not specified, ${PV} is used.

  For every argument pair specified, each of the version separators present at indices specified by the range is replaced with the replacement string, in order. If the range spans outside the range of present version separators, it is silently truncated.

ver_test

  Takes two or three arguments. In the 3-argument form, takes an LHS version string, followed by an operator, followed by an RHS version string. In the 2-argument form, the first version string is omitted and ${PVR} is used as LHS version string. The operator can be -eq (equal to), -ne (not equal to), -gt (greater than), -ge (greater than or equal to), -lt (less than) or -le (less than or equal to). Returns shell true (0) if the specified relation between the LHS and RHS version strings is fulfilled.

  Both version strings must conform to the version specification in section 3.2. Comparison is done using algorithm 3.1.

ver_replacing

  ver-replacing Takes an operator and a version string as arguments, which follow the same specification as in ver_test. Iterates over the elements of REPLACING_VERSIONS, using ver_test to compare each element against the version string. Returns shell true (0) if the specified relation holds for at least one element, shell false (1) otherwise. In particular, shell false is returned when REPLACING_VERSIONS is empty.

  Only available in EAPIs listed in table 12.23 as supporting ver_replacing. The command is only meaningful in phases where REPLACING_VERSIONS is defined.

Table 12.23: EAPIs supporting version manipulation commands

EAPI | ver_cut? | ver_rs? | ver_test? | ver_replacing?
0, 1, 2, 3, 4, 5, 6 | No | No | No | No
7, 8 | Yes | Yes | Yes | No
9 | Yes | Yes | Yes | Yes

#### 12.3.15 Misc commands

The following commands are always available in the ebuild environment, but don’t really fit in any of the above categories. Ebuilds must not run any of these commands once the current phase function has returned.

dosed

  Takes any number of arguments, which can be files or sed expressions. For each argument, if it names, relative to ED (offset-prefix aware EAPIs) or D (offset-prefix agnostic EAPIs) a file which exists, then sed is run with the current expression on that file. Otherwise, the current expression is set to the text of the argument. The initial value of the expression is s:${ED}::g in offset-prefix aware EAPIs and s:${D}::g in offset-prefix agnostic EAPIs. In EAPIs listed in table 12.3, this command is banned as per section 12.3.2.

unpack

  Unpacks one or more source archives, in order, into the current directory. For compressed files, creates the target file in the current directory, with the compression suffix removed from its name. After unpacking, must ensure that all filesystem objects inside the current working directory (but not the current working directory itself) have permissions a+r,u+w,go-w and that all directories under the current working directory additionally have permissions a+x.

  Arguments to unpack are interpreted as follows:

  - A filename without path (i. e. not containing any slash) is looked up in DISTDIR.
  - An argument starting with the string ./ is a path relative to the working directory.
  - unpack-absolute Otherwise, for EAPIs listed in table 12.24 as supporting absolute and relative paths, the argument is interpreted as a literal path (absolute, or relative to the working directory); for EAPIs listed as not supporting such paths, unpack shall abort the build process.

  Any unrecognised file format shall be skipped without raising an error. If unpacking a supported file format fails, unpack shall abort the build process.

  unpack-extensions Must be able to unpack the following file formats, if the relevant binaries are available:

  - tar files (*.tar). Ebuilds must ensure that GNU tar is installed.
  - gzip-compressed files (*.gz, *.z, *.Z). Ebuilds must ensure that GNU gzip is installed.
  - gzip-compressed tar files (*.tar.gz, *.tgz, *.tar.z, *.tar.Z). Ebuilds must ensure that GNU gzip and GNU tar are installed.
  - bzip2-compressed files (*.bz2, *.bz). Ebuilds must ensure that bzip2 is installed.
  - bzip2-compressed tar files (*.tar.bz2, *.tbz2, *.tar.bz, *.tbz). Ebuilds must ensure that bzip2 and GNU tar are installed.
  - zip files (*.zip, *.ZIP, *.jar). Ebuilds must ensure that Info-ZIP Unzip is installed.
  - 7zip files (*.7z, *.7Z). Ebuilds must ensure that P7ZIP is installed. Only for EAPIs listed in table 12.25 as supporting .7z.
  - rar files (*.rar, *.RAR). Ebuilds must ensure that RARLAB’s unrar is installed. Only for EAPIs listed in table 12.25 as supporting .rar.
  - LHA archives (*.LHA, *.LHa, *.lha, *.lzh). Ebuilds must ensure that the lha program is installed. Only for EAPIs listed in table 12.25 as supporting .lha.
  - ar archives (*.a). Ebuilds must ensure that GNU binutils is installed.
  - deb packages (*.deb). Ebuilds must ensure that the deb2targz program is installed on those platforms where the GNU binutils ar program is not available and the installed ar program is incompatible with GNU archives. Otherwise, ebuilds must ensure that GNU binutils is installed.
  - lzma-compressed files (*.lzma). Ebuilds must ensure that XZ Utils is installed.
  - lzma-compressed tar files (*.tar.lzma). Ebuilds must ensure that XZ Utils and GNU tar are installed.
  - xz-compressed files (*.xz). Ebuilds must ensure that XZ Utils is installed. Only for EAPIs listed in table 12.25 as supporting .xz.
  - xz-compressed tar files (*.tar.xz, *.txz). Ebuilds must ensure that XZ Utils and GNU tar are installed. Only for EAPIs listed in table 12.25 as supporting .tar.xz or .txz.

  It is up to the ebuild to ensure that the relevant external utilities are available, whether by being in the system set or via dependencies.

  unpack-ignore-case unpack matches filename extensions in a case-insensitive manner, for EAPIs listed such in table 12.24.

  Table 12.24: unpack behaviour for EAPIs

  EAPI | Supports absolute and relative paths? | Case-insensitive matching?
  0, 1, 2, 3, 4, 5 | No | No
  6, 7, 8, 9 | Yes | Yes

  Table 12.25: unpack extensions for EAPIs

  EAPI | .xz? | .tar.xz? | .txz? | .7z? | .rar? | .lha?
  0, 1, 2 | No | No | No | Yes | Yes | Yes
  3, 4, 5 | Yes | Yes | No | Yes | Yes | Yes
  6, 7 | Yes | Yes | Yes | Yes | Yes | Yes
  8, 9 | Yes | Yes | Yes | No | No | No

inherit

  See section 10.1.

default

  default-func Calls the default_ function for the current phase (see section 9.1.17). Must not be called if the default_ function does not exist for the current phase in the current EAPI. Only available in EAPIs listed in table 12.26 as supporting default.

einstalldocs

  einstalldocs Takes no arguments. Installs the files specified by the DOCS and HTML_DOCS variables or a default set of files, according to algorithm 12.3. If called using nonfatal and any of the called commands returns a non-zero exit status, returns immediately with the same exit status. Only available in EAPIs listed in table 12.26 as supporting einstalldocs.

  Algorithm 12.3: einstalldocs logic
  1: save the value of the install directory for dodoc
  2: set the install directory for dodoc to /usr/share/doc/${PF}
  3: if the DOCS variable is a non-empty array then
  4: call dodoc -r "${DOCS[@]}"
  5: else if the DOCS variable is a non-empty scalar then
  6: call dodoc -r ${DOCS}
  7: else if the DOCS variable is unset then
  8: for all d matching the filename expansion of README* ChangeLog AUTHORS NEWS TODO CHANGES THANKS BUGS FAQ CREDITS CHANGELOG do
  9: if file d exists and has a size greater than zero then
  10: call dodoc with d as argument
  11: end if
  12: end for
  13: end if
  14: set the install directory for dodoc to /usr/share/doc/${PF}/html
  15: if the HTML_DOCS variable is a non-empty array then
  16: call dodoc -r "${HTML_DOCS[@]}"
  17: else if the HTML_DOCS variable is a non-empty scalar then
  18: call dodoc -r ${HTML_DOCS}
  19: end if
  20: restore the value of the install directory for dodoc
  21: return shell true (0)

get_libdir

  get-libdir Prints the libdir name obtained according to algorithm 12.4. Must be implemented internally as a shell function and may be called in global scope. Only available in EAPIs listed in table 12.26 as supporting get_libdir.

  Algorithm 12.4: Library directory logic
  1: let libdir=lib
  2: if the ABI environment variable is set then
  3: let libvar=LIBDIR_$ABI
  4: if the environment variable named by libvar is set then
  5: let libdir=the value of the variable named by libvar
  6: end if
  7: end if
  8: return the value of libdir

edo

  edo Takes a command line, prints it to stderr and executes the command. Specifically, the entire list of (one or more) arguments is output as an informational message to stderr; individual tokens may be reformatted to avoid ambiguity. The first argument is then executed as a command, with the remaining arguments passed to it. If the command fails, edo aborts the build process using die, unless it was called under nonfatal, in which case it returns a non-zero exit status.

  edo must be implemented internally as a shell function. Only available in EAPIs listed in table 12.26 as supporting edo.

Table 12.26: Misc commands for EAPIs

EAPI | default? | einstalldocs? | get_libdir? | edo?
0, 1 | No | No | No | No
2, 3, 4, 5 | Yes | No | No | No
6, 7, 8 | Yes | Yes | Yes | No
9 | Yes | Yes | Yes | Yes

#### 12.3.16 Debug commands

The following commands are available for debugging. Normally all of these commands should be no ops; a package manager may provide a special debug mode where these commands instead do something. These commands must be implemented internally as shell functions and may be called in global scope. Ebuilds must not run any of these commands once the current phase function has returned.

debug-print

  If in a special debug mode, the arguments should be outputted or recorded using some kind of debug logging.

debug-print-function

  Calls debug-print with $1: entering function as the first argument and the remaining arguments as additional arguments.

debug-print-section

  Calls debug-print with now in section $*.

#### 12.3.17 Reserved commands and variables

Except where documented otherwise, all functions and variables that begin with any of the following strings (ignoring case) are reserved for package manager use and may not be used or relied upon by ebuilds:

- __ (two underscores)
- abort
- dyn
- prep

The same applies to functions and variables that contain any of the following strings (ignoring case):

- ebuild (unless immediately preceded by another letter)
- hook
- paludis
- portage

## Chapter 13
Merging and unmerging

  Note: In this chapter, file and regular file have their Unix meanings.

### 13.1 Overview

The merge process merges the contents of the D directory onto the filesystem under ROOT. This is not a straight copy; there are various subtleties which must be addressed.

The unmerge process removes an installed package’s files. It is not covered in detail in this specification.

### 13.2 Directories

Directories are merged recursively onto the filesystem. The method used to perform the merge is not specified, so long as the end result is correct. In particular, merging a directory may alter or remove the source directory under D.

Ebuilds must not attempt to merge a directory on top of any existing file that is not either a directory or a symlink to a directory.

#### 13.2.1 Permissions

The owner, group and mode (including set*id and sticky bits) of the directory must be preserved, except as follows:

- Any directory owned by the user used to perform the build must become owned by the superuser.
- Any directory whose group is the primary group of the user used to perform the build must have its group be that of the superuser.

On SELinux systems, the SELinux context must also be preserved. Other directory attributes, including modification time, may be discarded.

#### 13.2.2 Empty directories

Behaviour upon encountering an empty directory is undefined. Ebuilds must not attempt to install an empty directory.

### 13.3 Regular files

Regular files are merged onto the filesystem (but see the notes on configuration file protection, below). The method used to perform the merge is not specified, so long as the end result is correct. In particular, merging a regular file may alter or remove the source file under D.

Ebuilds must not attempt to merge a regular file on top of any existing file that is not either a regular file or a symlink to a regular file.

#### 13.3.1 Permissions

The owner, group and mode (including set*id and sticky bits) of the file must be preserved, except as follows:

- Any file owned by the user used to perform the build must become owned by the superuser.
- Any file whose group is the primary group of the user used to perform the build must have its group be that of the superuser.
- The package manager may reduce read and write permissions on executable files that have a set*id bit set.

On SELinux systems, the SELinux context must also be preserved. Other file attributes may be discarded.

#### 13.3.2 File modification times

mtime-preserve In EAPIs listed in table 13.1, the package manager must preserve modification times of regular files. This includes files being compressed before merging. Exceptions to this are files newly created by the package manager and binary object files being stripped of symbols.

When preserving, the seconds part of every regular file’s mtime must be preserved exactly. The sub-second part must either be set to zero, or set to the greatest value supported by the operating system and filesystem that is not greater than the sub-second part of the original time.

For any given destination filesystem, the package manager must ensure that for any two preserved files a, b in that filesystem the relation mtime(a) ≤ mtime(b) still holds, if it held under the original image directory.

In other EAPIs, the behaviour with respect to file modification times is undefined.

Table 13.1: Preservation of file modification times (mtimes)

EAPI | mtimes preserved?
0, 1, 2 | Undefined
3, 4, 5, 6, 7, 8, 9 | Yes

#### 13.3.3 Configuration file protection

The package manager must provide a means to prevent user configuration files from being overwritten by any package updates. The profile variables CONFIG_PROTECT and CONFIG_PROTECT_MASK (section 5.3) control the paths for which this must be enforced.

In order to ensure interoperability with configuration update tools, the following scheme must be used by all package managers when merging any regular file:

1.
  If the directory containing the file to be merged is not listed in CONFIG_PROTECT, and is not a subdirectory of any such directory, and if the file is not listed in CONFIG_PROTECT, the file is merged normally.
2.
  If the directory containing the file to be merged is listed in CONFIG_PROTECT_MASK, or is a subdirectory of such a directory, or if the file is listed in CONFIG_PROTECT_MASK, the file is merged normally.
3.
  If no existing file with the intended filename exists, or the existing file has identical content to the one being merged, the file is installed normally.
4.
  Otherwise, prepend the filename with ._cfg0000_. If no file with the new name exists, then the file is merged with this name.
5.
  Otherwise, increment the number portion (to form ._cfg0001_<name>) and repeat step 4. Continue this process until a usable filename is found.
6.
  If 9999 is reached in this way, behaviour is undefined.

### 13.4 Symlinks

Symlinks are merged as symlinks onto the filesystem. The link destination for a merged link shall be the same as the link destination for the link under D, except as noted below. The method used to perform the merge is not specified, so long as the end result is correct; in particular, merging a symlink may alter or remove the symlink under D.

Ebuilds must not attempt to merge a symlink on top of a directory.

#### 13.4.1 Rewriting

symlink-rewrite In EAPIs listed in table 13.2 as rewriting symlinks, any absolute symlink whose link target starts with D must be rewritten with the leading D removed. The package manager should issue a notice when encountering such a symlink. In all other EAPIs, symlinks must be merged with their targets unmodified.

Table 13.2: Rewriting of absolute symlinks in EAPIs

EAPI | Rewrite symlinks?
0, 1, 2, 3, 4, 5, 6, 7, 8 | Yes
9 | No

### 13.5 Hard links

A hard link may be merged either as a single file with links or as multiple independent files.

### 13.6 Other files

Ebuilds must not attempt to install any other type of file (FIFOs, device nodes etc).

## Chapter 14
Metadata cache

### 14.1 Directory contents

The metadata/cache or metadata/md5-cache directories, if either of them exists, contain directories whose names are the same as categories in the repository. Each subdirectory may optionally contain one file per package version in that category, named <package>-<version>, in one of the formats described below.

The metadata cache may be incomplete or non-existent, and may contain additional bogus entries.

### 14.2 Legacy cache file format

The legacy cache file format is used in the metadata/cache directory. Each cache file contains the textual values of various metadata keys, one per line, in the following order. Other lines may be present following these; their meanings are not defined here.

1.
  Build-time dependencies (DEPEND)
2.
  Run-time dependencies (RDEPEND)
3.
  Slot (SLOT)
4.
  Source tarball URIs (SRC_URI)
5.
  RESTRICT
6.
  Package homepage (HOMEPAGE)
7.
  Package license (LICENSE)
8.
  Package description (DESCRIPTION)
9.
  Package keywords (KEYWORDS)
10.
  Inherited eclasses (INHERITED)
11.
  Use flags that this package respects (IUSE)
12.
  Use flags that this package requires (REQUIRED_USE). Blank in some EAPIs; see table 7.2.
13.
  Post dependencies (PDEPEND)
14.
  Build-time dependencies for CBUILD host (BDEPEND). Blank in some EAPIs; see table 8.4.
15.
  The ebuild API version to which this package conforms (EAPI)
16.
  Properties (PROPERTIES). In some EAPIs, may optionally be blank, regardless of ebuild metadata; see table 7.2.
17.
  Defined phases (DEFINED_PHASES). In some EAPIs, may optionally be blank, regardless of ebuild metadata; see table 7.5.
18.
  Install-time dependencies (IDEPEND). Blank in some EAPIs; see table 8.4.
19.
  Blank lines to pad the file to 22 lines long

Future EAPIs may define new variables, remove existing variables, change the line number or format used for a particular variable, add or reduce the total length of the file and so on. Any future EAPI that uses this cache format will continue to place the EAPI value on line 15 if such a concept makes sense for that EAPI, and will place a value that is clearly not a supported EAPI on line 15 if it does not.

### 14.3 md5-dict cache file format

The “md5-dict” cache file format is used in the metadata/md5-cache directory. Each cache file contains <key>=<value> pairs, one per line, in arbitrary order. The keys are the same as those listed in section 14.2 except the INHERITED key. In addition, keys _md5_ and _eclasses_ contain values as defined below.

_md5_

  The MD5 checksum of the ebuild for the package version.

_eclasses_

  A list of name-checksum pairs for all eclasses directly or indirectly inherited by the ebuild, in arbitrary order, where name is the eclass name and checksum is the MD5 checksum of the eclass. Pairs are separated from each other by single tab characters, as are name and checksum in each pair.

All MD5 checksums are computed and formatted as described in RFC 1321 [2].

Other keys may be present; their meanings are not defined here. Lines with an empty value can be omitted.

## Glossary

This glossary contains explanations of some of the terms used in this document whose meaning may not be immediately obvious.

qualified package name

  A package name along with its associated category. For example, app-editors/vim is a qualified package name.

stand-alone repository

  An (ebuild) repository which is intended to function on its own as the only, or primary, repository on a system. Contrast with non-stand-alone repository below.

non-stand-alone repository

  An (ebuild) repository which is not complete enough to function on its own, but needs one or more master repositories to satisfy dependencies and provide repository-level support files. Known in Portage as an overlay.

master repository

  See above.

## Bibliography

[1] Michał Górny, Robin Hugh Johnson, and Ulrich Müller. Full-tree verification using Manifest files. GLEP 74, Gentoo Linux, October 2022. URL: https://www.gentoo.org/glep/glep-0074.html.

[2] Ronald L. Rivest. The MD5 message-digest algorithm. RFC 1321, RFC Editor, April 1992. URL: https://www.rfc-editor.org/rfc/rfc1321.

[3] Michał Górny. Package and category metadata. GLEP 68, Gentoo Linux, October 2022. URL: https://www.gentoo.org/glep/glep-0068.html.

[4] Jason Stubbs. Virtuals deprecation. GLEP 37, Gentoo Linux, September 2006. URL: https://www.gentoo.org/glep/glep-0037.html.

[5] Piotr Jaroszyński. Use EAPI-suffixed ebuilds. GLEP 55, Gentoo Linux, May 2009. URL: https://www.gentoo.org/glep/glep-0055.html.

## Appendix A
metadata.xml

The metadata.xml file is used to contain extra package- or category-level information beyond what is stored in ebuild metadata. Its exact format is strictly beyond the scope of this document, and is described in GLEP 68 [3].

## Appendix B
Unspecified items

The following items are not specified by this document, and must not be relied upon by ebuilds. This is, of course, an incomplete list—it covers only the things that the authors know have been abused in the past.

- The FEATURES variable. This is Portage specific.
- Similarly, any EMERGE_ variable and any PORTAGE_ variable.
- Any Portage configuration file.
- The VDB (/var/db/pkg). Ebuilds must not access this or rely upon it existing or being in any particular format.
- The portageq command. The has_version and best_version commands are available as functions.
- The emerge command.
- Binary packages.
- The PORTDIR_OVERLAY variable, and overlay behaviour in general.

## Appendix C
Historical curiosities

### C.1 Long-obsolete features

The items described in this section are included for information only. Unless otherwise noted, they were deprecated or abandoned long before EAPI was introduced. Ebuilds must not use these features, and package managers should not be changed to support them.

If-else USE blocks

  Historically, Portage supported if-else use conditionals, as shown by listing C.1. The block before the colon would be taken if the condition was met, and the block after the colon would be taken if the condition was not met.

  Listing C.1: If-else use blocks

      DEPEND="
          flag? (
              taken/if-true
          ) : (
              taken/if-false
          )
          "

CVS versions

  Portage has very crude support for CVS packages. The package foo could contain a file named foo-cvs.1.2.3.ebuild. This version would order higher than any non-CVS version (including foo-2.ebuild). This feature has not seen real world use and breaks versioned dependencies, so it must not be used.

use.defaults

  The use.defaults file in the profile directory was used to implement ‘autouse’—switching USE flags on or off depending upon which packages are installed. It was deprecated long ago and finally removed in 2009.

### C.2 Retroactive changes

In some exceptional cases, changes to the specification have been approved by the Gentoo Council without introducing a new EAPI. This section lists such retroactive changes.

Bash version

  EAPIs 0, 1 and 2 originally specified GNU Bash version 3.0. This was retroactively updated to version 3.2 (see table 6.1) in November 2009.

Old-style virtuals

  Historically, virtuals were special packages rather than regular ebuilds. An ebuild could specify in the PROVIDE metadata that it supplied certain virtuals, and the package manager had to bear this in mind when handling dependencies.

  Old-style virtuals were supported by EAPIs 0, 1, 2, 3 and 4. They were phased out via GLEP 37 [4] and finally removed in 2011.

    Note: A ‘new-style virtual’ is a normal package that installs no files and uses its dependency requirements to pull in a ‘provider’. This does not require any special handling from the package manager.

EAPI parsing

  The method to specify the EAPI of an ebuild used to be a shell variable assignment, and the package manager had to source the ebuild in order to determine the EAPI. Therefore any ebuild using a future EAPI would still have to be sourceable by old package managers, which imposed restrictions e. g. on updating the Bash version or on possible changes of global scope functions. Several approaches to overcome this limitation were discussed, notably GLEP 55 [5], which was ultimately rejected.

  The current syntax of the EAPI assignment statement (see section 7.3.1), allowing the package manager to obtain the EAPI from the ebuild by a regular expression match and without sourcing it, was introduced in May 2012.

Package names

  Previously, package names were only required not to end in a hyphen followed by one or more digits. In October 2012 this was tightened to the specification in section 3.1.2, namely that they must not end in a hyphen followed by anything resembling a package version.

Asterisk in dependency specification

  In the = dependency operator specified in section 8.3.1, an asterisk used to induce string prefix comparison instead of the normal version comparison logic. That could lead to surprising results, e. g. =dev-lang/perl-5.2* matching dev-lang/perl-5.22.0. Moreover, implementation in package managers deviated from what was specified.

  String prefix matching was effective in EAPIs 0, 1, 2, 3, 4 and 5. It was retroactively dropped in favour of the current behaviour in October 2015.

Empty dependency groups

  The dependency specification format (see section 8.2) originally permitted all-of, any-of, exactly-one-of, at-most-one-of and use-conditional groups with zero sub-elements. However, such empty groups were neither supported by all package managers nor used in ebuilds. They were dropped from the specification in October 2017.

econf --disable-static option

  The --disable-static option in econf (see section 12.3.8) was intended to disable only static Libtool archive building. The original check for either --disable-static or --enable-static occuring in configure --help output produced false positives.

  The test mentioned above was effective in EAPI 8. It was updated in November 2022 to require both --enable-static and --enable-shared, and in addition checks for a proper end of these option strings.

econf matches configure --help output better

  The simple string matching used for configure --help output caused false positives for options like --with-sysroot. It was effective in EAPIs 4, 5, 6, 7 and 8, and was updated in April 2023 to check for a proper end of string for all option names beginning with with-, disable- or enable-.

Dependency groups in HOMEPAGE

  The HOMEPAGE variable was originally listed as supporting dependency-style specifications, most notably use-conditional groups (see section 8.2). This feature was neither supported by Portage nor used in ebuilds. It was retroactively dropped from existing EAPIs in March 2026.

Path variables re-exported to environment

  EAPI 9 originally specified that SYSROOT, ESYSROOT and BROOT must not be exported. This was later found to break cross-compilation. Therefore, EAPI 9 was updated in June 2026 to export these variables to the environment again.

## Appendix D
Feature availability by EAPI

  Note: This chapter is informative and for convenience only. Refer to the main text for specifics. For lack of space, EAPIs 0 to 5 have been omitted from the table below, as well as items that would have identical entries for all listed EAPIs.

Table D.1: Features in EAPIs
Feature | Ref. | EAPIs
|  | 6 | 7 | 8 | 9
package.mask directory | package-mask-dir | No | Yes | Yes | Yes
Less strict updates syntax | updates-filenames | No | No | Yes | Yes
Default EAPI for profiles | profile-eapi-default | 0 | 0 | 0 | Top-level
Profile files as directories | profile-file-dirs | No | Yes | Yes | Yes
package.provided | package-provided | Optional | No | No | No
use.stable | use-stable | No | No | No | Yes
package.use.stable | use-stable | No | No | No | Yes
Bash version | bash-version | 4.2 | 4.2 | 5.0 | 5.3
Selective URI restrictions | uri-restrict | No | No | Yes | Yes
BDEPEND | bdepend | No | Yes | Yes | Yes
IDEPEND | idepend | No | No | Yes | Yes
Empty ||, ^^ groups match | empty-dep-groups | Yes | No | No | No
Working dir in pkg_* phases | phase-function-dir | Any | Any | Empty | Empty
src_prepare style | src-prepare | 6 | 6 | 8 | 8
Accumulate PROPERTIES | accumulate-vars | No | No | Yes | Yes
Accumulate RESTRICT | accumulate-vars | No | No | Yes | Yes
Export variables | export-vars | Yes | Yes | Yes | No
PORTDIR | portdir | Yes | No | No | No
ECLASSDIR | eclassdir | Yes | No | No | No
SYSROOT, ESYSROOT | sysroot | No | Yes | Yes | Yes
BROOT | broot | No | Yes | Yes | Yes
DESTTREE | desttree | Yes | No | No | No
INSDESTTREE | insdesttree | Yes | No | No | No
ENV_UNSET | env-unset | No | Yes | Yes | Yes
Trailing slash in D etc. | trailing-slash | Yes | No | No | No
GNU patch version | gnu-patch | Any | 2.7 | 2.7 | 2.7
nonfatal function / external | nonfatal | No | Yes | Yes | Yes
dohtml | banned-commands | Yes | Banned | Banned | Banned
dolib | banned-commands | Yes | Banned | Banned | Banned
libopts | banned-commands | Yes | Banned | Banned | Banned
useq | banned-commands | Yes | Yes | Banned | Banned
hasv | banned-commands | Yes | Yes | Banned | Banned
hasq | banned-commands | Yes | Yes | Banned | Banned
assert | banned-commands | Yes | Yes | Yes | Banned
domo | banned-commands | Yes | Yes | Yes | Banned
Query command options | pm-query-options | --host-root | -b, -d, -r | -b, -d, -r | -b, -d, -r
Output commands use stdout | output-no-stdout | Yes | No | No | No
eqawarn | eqawarn | No | Yes | Yes | Yes
die in subshell | subshell-die | No | Yes | Yes | Yes
pipestatus | pipestatus | No | No | No | Yes
econf --datarootdir | econf-options | No | No | Yes | Yes
econf --with-sysroot | econf-options | No | Yes | Yes | Yes
econf --disable-static | econf-options | No | No | Yes | Yes
domo destination path | domo-path | ${DESTTREE} | /usr | /usr | /usr
dosym -r | dosym-relative | No | No | Yes | Yes
insopts affects misc. cmds | insopts | Yes | Yes | No | No
exeopts affects doinitd | exeopts | Yes | Yes | No | No
Controllable stripping | dostrip | No | Yes | Yes | Yes
dostrip | dostrip | No | Yes | Yes | Yes
usev second arg | usev | No | No | Yes | Yes
ver_* commands | ver-commands | No | Yes | Yes | Yes
ver_replacing | ver-replacing | No | No | No | Yes
unpack support for 7z | unpack-extensions | Yes | Yes | No | No
unpack support for lha | unpack-extensions | Yes | Yes | No | No
unpack support for rar | unpack-extensions | Yes | Yes | No | No
edo | edo | No | No | No | Yes
Absolute symlink rewriting | symlink-rewrite | Yes | Yes | Yes | No

## Appendix E
Differences between EAPIs

  Note: This chapter is informative and for convenience only. Refer to the main text for specifics.

### EAPI 0

EAPI 0 is the base EAPI.

### EAPI 1

EAPI 1 is EAPI 0 with the following changes:

- IUSE defaults, iuse-defaults.
- Slot dependencies, slot-deps.
- Different src_compile implementation, src-compile.

### EAPI 2

EAPI 2 is EAPI 1 with the following changes:

- SRC_URI arrows, src-uri-arrows.
- Use dependencies, use-deps.
- ! and !! blockers, bang-strength.
- src_prepare, src-prepare.
- src_configure, src-configure.
- Different src_compile implementation, src-compile.
- default_ phase functions for phases pkg_nofetch, src_unpack, src_prepare, src_configure, src_compile and src_test; default-phase-funcs.
- doman language detection by filename, doman-langs.
- default function, default-func.

### EAPI 3

EAPI 3 is EAPI 2 with the following changes:

- Offset-prefix support by definition of EPREFIX, ED and EROOT, offset-prefix-vars.
- unpack supports .xz and .tar.xz, unpack-extensions.
- File modification times are preserved, mtime-preserve.

### EAPI 4

EAPI 4 is EAPI 3 with the following changes:

- REQUIRED_USE, required-use.
- PROPERTIES support is mandatory, properties.
- RDEPEND=DEPEND no longer done, rdepend-depend.
- DEFINED_PHASES support is mandatory, defined-phases.
- Use dependency defaults, use-dep-defaults.
- S to WORKDIR fallback restricted, s-workdir-fallback.
- pkg_pretend, pkg-pretend.
- Default src_install no longer a no-op, src-install.
- pkg_info can run on non-installed packages, pkg-info.
- AA is gone, aa.
- KV is gone, kv.
- MERGE_TYPE, merge-type.
- REPLACING_VERSIONS and REPLACED_BY_VERSION, replace-version-vars.
- Utilities now die on failure, die-on-failure, unless called under nonfatal, nonfatal
- dohard, dosed banned, banned-commands.
- econf adds --disable-dependency-tracking, econf-options.
- dodoc -r support, dodoc.
- doins supports symlinks, doins.
- doman -i18n option takes precedence, doman-langs.
- Controllable compression and docompress, docompress.
- use_with and use_enable support empty third argument, use-with.

### EAPI 5

EAPI 5 is EAPI 4 with the following changes:

- Stable use masking and forcing, stablemask.
- REQUIRED_USE now supports ?? groups, at-most-one-of.
- Slot operator dependencies, slot-operator-deps.
- SLOT now supports an optional sub-slot part, sub-slot.
- src_test supports parallel tests, parallel-tests.
- EBUILD_PHASE_FUNC, ebuild-phase-func.
- USE is calculated differently, profile-iuse-inject.
- find is guaranteed to be GNU, gnu-find.
- best_version and has_version support the --host-root option, pm-query-options.
- econf adds --disable-silent-rules, econf-options.
- doheader and newheader support, doheader.
- new* can read from standard input, newfoo-stdin.
- usex support, usex.

### EAPI 6

EAPI 6 is EAPI 5 with the following changes:

- Bash version is 4.2, bash-version.
- failglob is enabled in global scope, failglob.
- Default src_prepare no longer a no-op, src-prepare.
- Different src_install implementation, src-install.
- LC_CTYPE and LC_COLLATE compatible with POSIX locale, locale-settings.
- einstall banned, banned-commands.
- die and assert called with -n respect nonfatal, nonfatal-die.
- eapply support, eapply.
- eapply_user support, eapply-user.
- econf adds --docdir and --htmldir, econf-options.
- in_iuse support, in-iuse.
- unpack supports absolute and relative paths, unpack-absolute.
- unpack supports .txz, unpack-extensions.
- unpack matches filename extensions case-insensitively, unpack-ignore-case.
- einstalldocs support, einstalldocs.
- get_libdir support, get-libdir.

### EAPI 7

EAPI 7 is EAPI 6 with the following changes:

- profiles/package.mask can be a directory, package-mask-dir.
- package.mask, package.use, use.* and package.use.* in a profile can be directories, profile-file-dirs.
- package.provided in profiles banned, package-provided.
- Empty || and ^^ dependency groups no longer count as being matched, empty-dep-groups.
- PORTDIR is gone, portdir.
- ECLASSDIR is gone, eclassdir.
- DESTTREE is gone, desttree.
- INSDESTTREE is gone, insdesttree.
- ROOT, EROOT, D, ED no longer end with a trailing slash, trailing-slash.
- SYSROOT and ESYSROOT, sysroot.
- econf adds --with-sysroot, econf-options.
- BDEPEND, bdepend.
- BROOT, broot.
- best_version and has_version support -b, -d and -r options instead of --host-root, pm-query-options.
- ENV_UNSET, env-unset.
- patch is compatible with GNU patch 2.7, gnu-patch.
- nonfatal is both a shell function and an external command, nonfatal.
- dohtml banned, banned-commands.
- dolib and libopts banned, banned-commands.
- Output commands no longer use stdout, output-no-stdout.
- eqawarn, eqawarn.
- die is guaranteed to work in a subshell, subshell-die.
- domo installs to /usr, domo-path.
- Controllable stripping and dostrip, dostrip.
- Version manipulation and comparison commands, ver-commands.

### EAPI 8

EAPI 8 is EAPI 7 with the following changes:

- Less strict naming rules for files in updates directory, updates-filenames.
- Bash version is 5.0, bash-version.
- Selective fetch/mirror restriction, uri-restrict.
- IDEPEND, idepend.
- Empty working directory in pkg_* phase functions, phase-function-dir.
- Different src_prepare implementation, src-prepare.
- PROPERTIES and RESTRICT accumulated across eclasses, accumulate-vars.
- useq banned, banned-commands.
- hasv and hasq banned, banned-commands.
- econf adds --datarootdir, econf-options.
- econf adds --disable-static, econf-options.
- dosym can create relative paths, dosym-relative.
- insopts no longer affects doconfd, doenvd and doheader, insopts.
- exeopts no longer affects doinitd, exeopts.
- usev supports an optional second argument, usev.
- unpack no longer supports .7z, .rar, .lha, unpack-extensions.

### EAPI 9

EAPI 9 is EAPI 8 with the following changes:

- Different default EAPI for profiles, profile-eapi-default.
- use.stable and package.use.stable, use-stable.
- Bash version is 5.3, bash-version.
- Variables no longer exported, export-vars.
- assert banned, banned-commands.
- domo banned, banned-commands.
- pipestatus, pipestatus.
- ver_replacing, ver-replacing.
- edo, edo.
- Absolute symlinks no longer rewritten, symlink-rewrite.

## Appendix F
Desk reference

EAPI Cheat Sheet

1 May change if a package has been updated (see section 4.4.4).

2 This variable is generally considered deprecated. However, ebuilds must still assume that the package manager sets it in the EAPIs supporting it. For example, a few configure scripts use this variable to find the aalib package; ebuilds calling such configure scripts must thus work around this.

3 Not necessarily present when installing from a binary package. Ebuilds must not access the directory in global scope.

4 Not necessarily present when installing from a binary package.

5 Legal in pkg_*inst and pkg_*rm only for EAPIs listed in table 8.4 as supporting IDEPEND.

6 Consistent and preserved across a single connected sequence of install or uninstall phases, but not between install and uninstall. When reinstalling a package, this variable must have different values for the install and the replacement.

7 May not necessarily have the same value that it had in the src_* phases.