Overlay for latest flatpak version

Help
1

Hey all,

I need flatpak 1.15.4 for an application to work properly, so I wanted to install it using an overlay. When rebuilding the system tho I get a different sha256 sum then the one stated on the flatpak github (https://github.com/flatpak/flatpak/releases/tag/1.15.4).

So I get
sha256-6rg6RoqDrThkQAgZ9GwLOhKDnBFFMBVUzhjxWua3oKw=
instead of
bef695d893d1e0239a68441d6b328edeb6d1e58a902c92f9278e94da914ab91f

My question is if I have done something wrong in my overlay:

{
nixpkgs = {
  config.allowUnfree = true;
  overlays = [
    (final: prev: {
      flatpak = prev.flatpak.overrideAttrs (old: {
        src = prev.fetchFromGitHub {
          owner = "flatpak";
          repo = "flatpak";
          rev = "1.15.4";
          hash = ""; # Left empty to get sha256sum
        };
      });
    })
  ];
};
}

As a template I used the example in the wiki (Overlays).

2

The hash on the release page is for the archive generated by flatpak. We are downloading the auto generated ones and unpack them which gives a different hash.

3

So everything is correct and I just have to use the hash nix outputs if I understand correctly?