How to pick an old channel version for npins?

Help
1

I’m using npins to manage my nixpkgs version for my mutable NixOS install.

I just did npins update, leaving me with a version that causes Build failure: noto-fonts-subset (affecting libreoffice) #495219 which is fixed in libreoffice: remove noto-sans font workaround#494721 .

    "nixpkgs": {
      "type": "Channel",
      "name": "nixos-unstable",
      "url": "https://releases.nixos.org/nixos/unstable/nixos-26.05pre955442.dd9b079222d4/nixexprs.tar.xz",
      "hash": "sha256-UCaQQ8zmHUocQIgCl+53Jj6NuwqrVKtmv7obE9r6wnw="
    }
  },
  "version": 7

How do I invoke npins to select an older version of the nixos-unstable channel that does not have this issue?

2

Answer:

Go to the Hydra tested build queue for the channel Hydra nixos:unstable:tested and pick out a package/release name, edit it into the URL and npins verify nixpkgs to get the correct hash to edit in.

Then get a FTBFS because a random dependency of Krita can’t find Boost :slight_smile:, give up and wait for a valid update I guess!

3

Self-plug: I wrote a tool called npc to solve basically this problem :slight_smile: