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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.

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