flake-input-patcher

Tired of waiting for PRs to land? Stop waiting!

Utility to patch nix flake inputs.

This can go away when nix supports patching flake inputs: NixOS/nix#3920.

Usage

Usage in a flake.nix:

{
  inputs = {
    flake-input-patcher.url = "github:jfly/flake-input-patcher";
    # ... More inputs here ...
  };

  outputs =
    unpatchedInputs:
    let
      # Unfortunately, this utility requires hardcoding a single system. See
      # "Known issues" below.
      patcher = unpatchedInputs.flake-input-patcher.lib.x86_64-linux;

      inputs = patcher.patch unpatchedInputs {
        # Patching a direct dependency:
        nixpkgs.patches = [
          (patcher.fetchpatch {
            name = "k3s: use patched util-linuxMinimal";
            url = "https://github.com/NixOS/nixpkgs/pull/407810.diff";
            hash = "sha256-N8tzwSZB9d4Htvimy00+Jcw8TKRCeV8PJWp80x+VtSk=";
          })
        ];

        # Patching a transitive dependency:
        clan-core.inputs.data-mesher.patches = [
           # ... More patches here ...
        ];
      };
    in
    # Define your flake as normal using `inputs`!
}

Known issues

• We currently don't understand anything about input following, so you can end up in inconsistent states. For example, if you patch your top level nixpkgs, that doesn't affect transitive dependencies that follow that nixpkgs. Ideally we'd import flake.nix and honor the follows.
• nix does not (yet) have a patch builtin, so we use system-specific utilities in nixpkgs (fetchpatch and applyPatches), which means you have to hardcode a system to make it work.
• This depends on Input From Derivation (IFD).

Alternatives

• Be more patient and wait for PRs to land. You are trying to upstream your patches, aren't you?
• Tediously hand-write overlays/overrides for changes you need/want. This won't help with NixOS module changes.
• Maintain your own forks of your inputs.
  • nix-patcher is designed to automate this process. It looks like it only works for inputs hosted on GitHub.
• gepbird/nixpkgs-patcher implements a similar IFD helper. Also see this feature comparison table

In the wild

Feel free to add a link to your repo here!

• jfly/snow