Testing with Nix 2.2.

[Zimmi48]

Hi!

The documentation seems to indicate that it should be possible to run this action with an older Nix version by using the install_url input. I've tried testing with Nix 2.2 by setting install_url: https://releases.nixos.org/nix/nix-2.2/install but I've obtained the following error:

/dev/fd/63: SHA-256 hash mismatch in 'https://nixos.org/releases/nix/nix-2.2/nix-2.2-x86_64-darwin.tar.bz2';
expected sha256-1zRgN1HUvaA+FJjOLSVlLv5+f9bdHBbBVKTBYTpSj68=,
got d734603751d4bda03e1498ce2d25652efe7e7fd6dd1c16c154a4c1613a528faf

Is testing with Nix 2.2 supported and if yes how? Otherwise, do you have any suggestion on how to test build a derivation with Nix 2.2? (I am trying to understand why a PR fails in nixpkgs's CI while the same derivation builds fine in GitHub Actions and I suspect that it might be due to the version of Nix since I don't see any other explanation for the inconsistency.)

[domenkozar]

That looks like a problem with the installer itself expecting a different hash of the tarball for installation.

I'd suggest to open an issue since it's important to fix this

[Zimmi48]

OK. You mean opening an issue in the Nix repository itself, right?

[domenkozar]

That or https://github.com/NixOS/nixos-homepage

[Zimmi48]

Done. Note that I didn't have more luck when trying to install Nix 2.3 (or Nix 2.3.4) as it failed with a different error (later in the process):

Error: Command failed: /Users/runner/work/_actions/cachix/install-nix-action/v12/lib/install-nix.sh
    at checkExecSyncError (child_process.js:621:11)
    at Object.execFileSync (child_process.js:639:15)
    at Object.<anonymous> (/Users/runner/work/_actions/cachix/install-nix-action/v12/lib/main.js:4:17)
    at Module._compile (internal/modules/cjs/loader.js:959:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:995:10)
    at Module.load (internal/modules/cjs/loader.js:815:32)

    at Function.Module._load (internal/modules/cjs/loader.js:727:14)
    at Function.Module.runMain (internal/modules/cjs/loader.js:1047:10)
    at internal/main/run_main_module.js:17:11 {
  status: 1,
  signal: null,
  output: [ null, null, null ],
  pid: 1156,
  stdout: null,
  stderr: null
}

And when trying to reproduce the problem using Travis, I got a different error (https://travis-ci.community/t/cannot-run-travis-with-nix-2-2-or-2-3/12203).

With both GitHub Actions and Travis, it starts working fine with Nix 2.3.5, but I have no idea if the reasons it fails are related.

[domenkozar]

You'd have to use an older version of the action, as the latest one uses features from Nix 2.3.11 (iirc) to speed up the installation.

[Zimmi48]

OK thanks for the clarification. I think it'd be worth adding this piece of info (minimal supported Nix version) in the documentation then.