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

Name

nix flake prefetch - download the source tree denoted by a flake reference into the Nix store

Synopsis

nix flake prefetch [option...] flake-url

Examples

  • Download a tarball and unpack it:

    # nix flake prefetch https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.5.tar.xz
    Downloaded 'https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.5.tar.xz?narHash=sha256-3XYHZANT6AFBV0BqegkAZHbba6oeDkIUCDwbATLMhAY='
    to '/nix/store/sl5vvk8mb4ma1sjyy03kwpvkz50hd22d-source' (hash
    'sha256-3XYHZANT6AFBV0BqegkAZHbba6oeDkIUCDwbATLMhAY=').
    
  • Download the dwarffs flake (looked up in the flake registry):

    # nix flake prefetch dwarffs --json
    {"hash":"sha256-VHg3MYVgQ12LeRSU2PSoDeKlSPD8PYYEFxxwkVVDRd0="
    ,"storePath":"/nix/store/hang3792qwdmm2n0d9nsrs5n6bsws6kv-source"}
    

Description

This command downloads the source tree denoted by flake reference flake-url. Note that this does not need to be a flake (i.e. it does not have to contain a flake.nix file).

Options

  • --json
    Produce output in JSON format, suitable for consumption by another program.

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).