nix registry pin - Lix Reference Manual

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

# Name

`nix registry pin` - pin a flake to its current version or to the current version of a flake URL

# 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

- `--registry` registry The registry to operate on.

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://channels.nixos.org/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'.

- `--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.