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.

       •  --arg-from-file name path

          Pass the contents of file path as the argument name to Nix functions.

       •  --arg-from-stdin name

          Pass the contents of stdin as the argument name to Nix functions.

       •  --argstr name string

          Pass the string string as the argument name to Nix functions.

       •  --debugger

          Start an interactive environment if evaluation fails.

       •  --eval-store store-url

          The  URL of the Nix store  to  use  for  evaluation, i.e. to store derivations (.drv files) and inputs
          referenced by them.

       •  --impure

          Allow access to mutable paths and repositories.

       •  --include / -I path

          Add path to search path entries used to resolve lookup paths

          This option may be given multiple times.

          Paths added through -I take  precedence  over  the  nix-path configuration setting  and  the  NIX_PATH
          environment variable.

       •  --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.

                 DEPRECATED

                 Use --no-use-registries instead.

       •  --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.

       •  --output-lock-file flake-lock-path

          Write the given lock file instead of flake.lock within the top-level flake.

       •  --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.

                 DEPRECATED

                 Use nix flake update instead.

       •  --reference-lock-file flake-lock-path

          Read the given lock file instead of flake.lock within the top-level flake.

       •  --update-input input-path

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

                 DEPRECATED

                 Use nix flake update instead.

   Logging-related options
       •  --debug

          Set the logging verbosity level to ‘debug’.

       •  --log-format format

          Set the format of log output; one of raw, internal-json, bar or bar-with-logs.

       •  --print-build-logs / -L

          Print full build logs on standard error.

       •  --quiet

          Decrease the logging verbosity level.

       •  --verbose / -v

          Increase the logging verbosity level.

   Miscellaneous global options
       •  --help

          Show usage information.

       •  --offline

          Disable substituters and consider all previously downloaded files up-to-date.

       •  --option name value

          Set the Nix configuration setting name to value (overriding nix.conf).

       •  --refresh

          Consider all previously downloaded files out-of-date.

       •  --repair

          During  evaluation,  rewrite  missing  or  corrupted  files in the Nix store. During building, rebuild
          missing or corrupted store paths.

       •  --version

          Show version information.

          Note

          See man nix.conf for overriding configuration settings with command line flags.

                                                                                          nix3-flake-prefetch(1)