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nix registry pin

Pin a flake to its current version or to the current version of a flake URL.

Warning

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

Synopsis

nix registry pin [option...] url locked

Examples

  • Pin nixpkgs to its most recent Git revision:
## nix registry pin nixpkgs

Afterwards the user registry will have an entry like this:

nix registry list | grep '^user '
user   flake:nixpkgs github:NixOS/nixpkgs/925b70cd964ceaedee26fde9b19cc4c4f081196a

and nix flake info will say:

## nix flake info nixpkgs
Resolved URL:  github:NixOS/nixpkgs/925b70cd964ceaedee26fde9b19cc4c4f081196a
Locked URL:    github:NixOS/nixpkgs/925b70cd964ceaedee26fde9b19cc4c4f081196a
…
  • Pin nixpkgs in a custom registry to its most recent Git revision:
## nix registry pin --registry ./custom-flake-registry.json nixpkgs

Description

This command adds an entry to the user registry that maps flake reference url to the corresponding locked flake reference, that is, a flake reference that specifies an exact revision or content hash. This ensures that until this registry entry is removed, all uses of url will resolve to exactly the same flake.

Entries can be removed using nix registry remove.

Options

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.

  • --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 the Nix search path. The Nix search path is initialized from the colon-separated NIX_PATH environment 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/nixos

will cause Lix to look for paths relative to /home/eelco/Dev and /etc/nixos, in that order. This is equivalent to setting the NIX_PATH environment variable to

/home/eelco/Dev:/etc/nixos

It is also possible to match paths against a prefix. For example, passing

-I nixpkgs=/home/eelco/Dev/nixpkgs-branch
-I /etc/nixos

will cause Lix to search for <nixpkgs/path> in /home/eelco/Dev/nixpkgs-branch/path and /etc/nixos/nixpkgs/path.

If a path in the Nix search path starts with http:// or https://, 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.gz

tells Lix to download and use the current contents of the master branch in the nixpkgs repository.

The URLs of the tarballs from the official nixos.org channels (see the manual page for nix-channel) can be abbreviated as channel:<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.xz

You can also fetch source trees using flake URLs and add them to the search path. For instance,

-I nixpkgs=flake:nixpkgs

specifies that the prefix nixpkgs shall refer to the source tree downloaded from the nixpkgs entry in the flake registry. Similarly,

-I nixpkgs=flake:github:NixOS/nixpkgs/nixos-22.05

makes <nixpkgs> refer to a particular branch of the NixOS/nixpkgs repository on GitHub.

  • --override-flake original-ref resolved-ref Override the flake registries, redirecting original-ref to resolved-ref.

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 Lix 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.