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


nix flake show - show the outputs provided by a flake


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


  • Show the output attributes provided by the patchelf flake:

    │   ├───aarch64-linux
    │   │   └───build: derivation 'patchelf-0.12.20201207.f34751b'
    │   ├───i686-linux
    │   │   └───build: derivation 'patchelf-0.12.20201207.f34751b'
    │   └───x86_64-linux
    │       └───build: derivation 'patchelf-0.12.20201207.f34751b'
    │   ├───aarch64-linux
    │   │   └───default: package 'patchelf-0.12.20201207.f34751b'
    │   ├───i686-linux
    │   │   └───default: package 'patchelf-0.12.20201207.f34751b'
    │   └───x86_64-linux
    │       └───default: package 'patchelf-0.12.20201207.f34751b'
    │   ├───build
    │   │   ├───aarch64-linux: derivation 'patchelf-0.12.20201207.f34751b'
    │   │   ├───i686-linux: derivation 'patchelf-0.12.20201207.f34751b'
    │   │   └───x86_64-linux: derivation 'patchelf-0.12.20201207.f34751b'
    │   ├───coverage: derivation 'patchelf-coverage-0.12.20201207.f34751b'
    │   ├───release: derivation 'patchelf-0.12.20201207.f34751b'
    │   └───tarball: derivation 'patchelf-tarball-0.12.20201207.f34751b'
    └───overlay: Nixpkgs overlay


This command shows the output attributes provided by the flake specified by flake reference flake-url. These are the top-level attributes in the outputs of the flake, as well as lower-level attributes for some standard outputs (e.g. packages or checks).

With --json, the output is in a JSON representation suitable for automatic processing by other tools.


  • --debugger
    start an interactive environment if evaluation fails

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

  • --legacy
    Show the contents of the legacyPackages output.

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).