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
patchelfflake 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, Lix 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.namedefaultPackage.systemdevShell.systemdevShells.system.namenixosConfigurations.name.config.system.build.toplevelpackages.system.name
The following flake output attributes must be app definitions:
apps.system.namedefaultApp.system
The following flake output attributes must be template definitions:
defaultTemplatetemplates.name
The following flake output attributes must be Nixpkgs overlays:
overlayoverlays.name
The following flake output attributes must be NixOS modules:
nixosModulenixosModules.name
The following flake output attributes must be bundlers:
bundlers.namedefaultBundler
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 --query --available .
Options
-
--all-systemsCheck the outputs for all systems. -
--no-buildDo not build checks.
Common evaluation options:
-
--argname expr Pass the value expr as the argument name to Nix functions. -
--argstrname string Pass the string string as the argument name to Nix functions. -
--debuggerStart an interactive environment if evaluation fails. -
--eval-storestore-url The URL of the Nix store to use for evaluation, i.e. to store derivations (.drvfiles) and inputs referenced by them. -
--impureAllow access to mutable paths and repositories. -
--include/-Ipath Add path to the Nix search path. The Nix search path is initialized from the colon-separatedNIX_PATHenvironment variable, and is used to look up the location of Nix expressions using paths enclosed in angle brackets (i.e.,<nixpkgs>).For instance, passing
-I /home/eelco/Dev -I /etc/nixoswill cause Lix to look for paths relative to
/home/eelco/Devand/etc/nixos, in that order. This is equivalent to setting theNIX_PATHenvironment variable to/home/eelco/Dev:/etc/nixosIt is also possible to match paths against a prefix. For example, passing
-I nixpkgs=/home/eelco/Dev/nixpkgs-branch -I /etc/nixoswill cause Lix to search for
<nixpkgs/path>in/home/eelco/Dev/nixpkgs-branch/pathand/etc/nixos/nixpkgs/path.If a path in the Nix search path starts with
http://orhttps://, it is interpreted as the URL of a tarball that will be downloaded and unpacked to a temporary location. The tarball must consist of a single top-level directory. For example, passing-I nixpkgs=https://github.com/NixOS/nixpkgs/archive/master.tar.gztells Lix to download and use the current contents of the
masterbranch in thenixpkgsrepository.The URLs of the tarballs from the official
nixos.orgchannels (see the manual page fornix-channel) can be abbreviated aschannel:<channel-name>. For instance, the following two flags are equivalent:-I nixpkgs=channel:nixos-21.05 -I nixpkgs=https://nixos.org/channels/nixos-21.05/nixexprs.tar.xzYou can also fetch source trees using flake URLs and add them to the search path. For instance,
-I nixpkgs=flake:nixpkgsspecifies that the prefix
nixpkgsshall refer to the source tree downloaded from thenixpkgsentry in the flake registry. Similarly,-I nixpkgs=flake:github:NixOS/nixpkgs/nixos-22.05makes
<nixpkgs>refer to a particular branch of theNixOS/nixpkgsrepository on GitHub. -
--override-flakeoriginal-ref resolved-ref Override the flake registries, redirecting original-ref to resolved-ref.
Common flake-related options:
-
--commit-lock-fileCommit changes to the flake's lock file. -
--inputs-fromflake-url Use the inputs of the specified flake as registry entries. -
--no-registriesDon't allow lookups in the flake registries. This option is deprecated; use--no-use-registries. -
--no-update-lock-fileDo not allow any updates to the flake's lock file. -
--no-write-lock-fileDo not write the flake's newly generated lock file. -
--output-lock-fileflake-lock-path Write the given lock file instead offlake.lockwithin the top-level flake. -
--override-inputinput-path flake-url Override a specific flake input (e.g.dwarffs/nixpkgs). This implies--no-write-lock-file. -
--reference-lock-fileflake-lock-path Read the given lock file instead offlake.lockwithin the top-level flake.
Logging-related options:
-
--debugSet the logging verbosity level to 'debug'. -
--log-formatformat Set the format of log output; one ofraw,internal-json,bar,bar-with-logs,multilineormultiline-with-logs. -
--print-build-logs/-LPrint full build logs on standard error. -
--quietDecrease the logging verbosity level. -
--verbose/-vIncrease the logging verbosity level.
Miscellaneous global options:
-
--helpShow usage information. -
--offlineDisable substituters and consider all previously downloaded files up-to-date. -
--optionname value Set the Lix configuration setting name to value (overridingnix.conf). -
--refreshConsider all previously downloaded files out-of-date. -
--repairDuring evaluation, rewrite missing or corrupted files in the Nix store. During building, rebuild missing or corrupted store paths. -
--versionShow version information.
Note
See
man nix.conffor overriding configuration settings with command line flags.