nix3-flake-check(1)

check whether the flake evaluates and run its tests Cnix flake check [option] flake-url Evaluate the flake in the curren

Section 1 nix-bin bookworm source

Description

nix3-flake-check

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

Name

nix flake check - check whether the flake evaluates and run its tests

Synopsis

nix flake check [option…] flake-url

Examples

Evaluate the flake in the current directory, and build its checks:

# nix flake check

Verify that the patchelf flake evaluates, but don’t build its checks:

# nix flake check --no-build github:NixOS/patchelf

Description

This command verifies that the flake specified by flake reference flake-url can be evaluated successfully (as detailed below), and that the derivations specified by the flake’s checks output can be built successfully.

If the keep-going option is set to true, Nix will keep evaluating as much as it can and report the errors as it encounters them. Otherwise it will stop at the first error.

Evaluation checks

The following flake output attributes must be derivations:

checks.system.name

defaultPackage.system

devShell.system

devShells.system.name

nixosConfigurations.name.config.system.build.toplevel

packages.system.name

The following flake output attributes must be app definitions (./nix3-run.md):

apps.system.name

defaultApp.system

The following flake output attributes must be template definitions (./nix3-flake-init.md):

defaultTemplate

templates.name

The following flake output attributes must be Nixpkgs overlays:

overlay

overlays.name

The following flake output attributes must be NixOS modules:

nixosModule

nixosModules.name

The following flake output attributes must be bundlers (./nix3-bundle.md):

bundlers.name

defaultBundler

In addition, the hydraJobs output is evaluated in the same way as Hydra’s hydra-eval-jobs (i.e. as a arbitrarily deeply nested attribute set of derivations). Similarly, the legacyPackages.system output is evaluated like nix-env -qa.

Options

--no-build

Do not build checks.

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).