Nix Registry Add: Examples and Description

src/nix/registry-add.md

443453178c9ac30780cb00e5b148b2a2943954b3bf5f6f6100000003000003b6

R""(

# Examples

* Set the `nixpkgs` flake identifier to a specific branch of Nixpkgs:

  ```console
  # nix registry add nixpkgs github:NixOS/nixpkgs/nixos-20.03
  ```

* Pin `nixpkgs` to a specific revision:

  ```console
  # nix registry add nixpkgs github:NixOS/nixpkgs/925b70cd964ceaedee26fde9b19cc4c4f081196a
  ```

* Add an entry that redirects a specific branch of `nixpkgs` to
  another fork:

  ```console
  # nix registry add nixpkgs/nixos-20.03 ~/Dev/nixpkgs
  ```

* Add `nixpkgs` pointing to `github:nixos/nixpkgs` to your custom flake
  registry:

  ```console
  nix registry add --registry ./custom-flake-registry.json nixpkgs github:nixos/nixpkgs
  ```

# Description

This command adds an entry to the user registry that maps flake
reference *from-url* to flake reference *to-url*. If an entry for
*from-url* already exists, it is overwritten.

Entries can be removed using [`nix registry
remove`](./nix3-registry-remove.md).

)""

Chunks

909274d8 (1st chunk of `src/nix/registry-add.md`)

Title: Nix Registry Add: Examples and Description

Summary

This section provides examples of how to use the `nix registry add` command to manage flake references. It demonstrates adding Nixpkgs from a branch, pinning to a specific revision, redirecting a branch to a fork, and adding Nixpkgs to a custom flake registry. The command maps a 'from-url' flake reference to a 'to-url' flake reference in the user registry, overwriting any existing entry for 'from-url'. The `nix registry remove` command can be used to remove entries.