DOKK / manpages / debian 12 / nix-bin / nix3-copy.1.en
nix3-copy(1) General Commands Manual nix3-copy(1)

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

nix copy - copy paths between Nix stores

nix copy [option…] installables

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

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.

  • --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.