nix copy

Warning: This program is experimental and its interface is subject to change.

# Name

`nix copy` - copy paths between Nix stores

# Synopsis

`nix copy` [option...] installables...

# Examples

- Copy Firefox from the local store to a binary cache in `/tmp/cache`:

      # nix copy --to file:///tmp/cache $(type -p firefox)

  Note the `file://` - without this, the destination is a chroot store, not a binary cache.

- Copy the entire current NixOS system closure to another machine via SSH:

      # nix copy -s --to ssh://server /run/current-system

  The `-s` flag causes the remote machine to try to substitute missing store paths, which may be faster if the link between the local and remote machines is slower than the link between the remote machine and its substituters (e.g. `https://cache.nixos.org`).

- Copy a closure from another machine via SSH:

      # nix copy --from ssh://server /nix/store/a6cnl93nk1wxnq84brbbwr6hxw9gp2w9-blender-2.79-rc2

- Copy Hello to a binary cache in an Amazon S3 bucket:

      # nix copy --to s3://my-bucket?region=eu-west-1 nixpkgs#hello

  or to an S3-compatible storage system:

      # nix copy --to s3://my-bucket?region=eu-west-1&endpoint=example.com nixpkgs#hello

  Note that this only works if Nix is built with AWS support.

- Copy a closure from `/nix/store` to the chroot store `/tmp/nix/nix/store`:

      # nix copy --to /tmp/nix nixpkgs#hello --no-check-sigs

# Description

`nix copy` copies store path closures between two Nix stores. The source store is specified using `--from` and the destination using `--to`. If one of these is omitted, it defaults to the local store.

# Options

- `--from` store-uri
  URL of the source Nix store.

- `--no-check-sigs`
  Do not require that paths are signed by trusted keys.

- `--substitute-on-destination` / `-s`
  Whether to try substitutes on the destination store (only supported by SSH stores).

- `--to` store-uri
  URL of the destination Nix store.

Common evaluation options:

- `--arg` name expr
  Pass the value expr as the argument name to Nix functions.

- `--argstr` name string
  Pass the string string as the argument name to Nix functions.

- `--eval-store` store-url
  The Nix store to use for evaluations.

- `--impure`
  Allow access to mutable paths and repositories.

- `--include` / `-I` path
  Add path to the list of locations used to look up `<...>` file names.

- `--override-flake` original-ref resolved-ref
  Override the flake registries, redirecting original-ref to resolved-ref.

Common flake-related options:

- `--commit-lock-file`
  Commit changes to the flake's lock file.

- `--inputs-from` flake-url
  Use the inputs of the specified flake as registry entries.

- `--no-registries`
  Don't allow lookups in the flake registries. This option is deprecated; use `--no-use-registries`.

- `--no-update-lock-file`
  Do not allow any updates to the flake's lock file.

- `--no-write-lock-file`
  Do not write the flake's newly generated lock file.

- `--override-input` input-path flake-url
  Override a specific flake input (e.g. `dwarffs/nixpkgs`). This implies `--no-write-lock-file`.

- `--recreate-lock-file`
  Recreate the flake's lock file from scratch.

- `--update-input` input-path
  Update a specific flake input (ignoring its previous entry in the lock file).

Options that change the interpretation of installables:

- `--all`
  Apply the operation to every store path.

- `--derivation`
  Operate on the store derivation rather than its outputs.

- `--expr` expr
  Interpret installables as attribute paths relative to the Nix expression expr.

- `--file` / `-f` file
  Interpret installables as attribute paths relative to the Nix expression stored in file. If file is the character -, then a Nix expression will be read from standard input.

- `--no-recursive`
  Apply operation to specified paths only.