haskellPackages.Agda: unbreak the build by dropping a (by now) unnecessary patch

[iblech]

Motivation for this change

Without this commit, building Agda fails as follows:

$ nix-shell -p agda
these derivations will be built:
  /nix/store/j13y12xa4g6dkn60k6y0ypp3rs62r7zn-Agda-2.6.1.3.drv
  /nix/store/xcvdw97bglp440pr0ad0xqqlk8lvxagc-agdaWithPackages-2.6.1.3.drv
building '/nix/store/j13y12xa4g6dkn60k6y0ypp3rs62r7zn-Agda-2.6.1.3.drv'...
[...]
applying patch /nix/store/38bnrnh7sbfawsyll5hlzijzvf9x09q2-76278c23d447b49f59fac581ca4ac605792aabbc.patch
patching file Agda.cabal
Hunk #1 FAILED at 249.
1 out of 1 hunk FAILED -- saving rejects to file Agda.cabal.rej
builder for '/nix/store/j13y12xa4g6dkn60k6y0ypp3rs62r7zn-Agda-2.6.1.3.drv' failed with exit code 1
cannot build derivation '/nix/store/xcvdw97bglp440pr0ad0xqqlk8lvxagc-agdaWithPackages-2.6.1.3.drv': 1 dependencies couldn't be built
error: build of '/nix/store/xcvdw97bglp440pr0ad0xqqlk8lvxagc-agdaWithPackages-2.6.1.3.drv' failed

The patch the build is complaining about was necessary for Agda 2.6.1.2, fixing a version bound in the Cabal file. Meanwhile this patch has found its way into upstream Agda 2.6.1.3 and is hence no longer required.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.

[sternenseemann]

This is already fixed on haskell-updates: 3868c09 Thus the fix will land in master on friday when the haskellPackages set is updated (see #112936). Unfortunately due to the way the haskellPackages set is maintained, there is up to a week of delay between a fix and it landing in master (which then takes time to propagates to nixos-unstable).

You might also find this video explaining the fixing process for haskellPackages interesting.

[iblech]

Ah, I see. Thank you very much for the detailed explanation and the many pointers. I'll have a look at the video, right now the Haskell update process is still a bit of a mystery to me. :-) I'll close this. (Nice to meet over NixOS pull request discussions, @sternenseemann! :-))

[sternenseemann]

If you need agda urgently, nix-shell -p agda -I nixpkgs=https://github.com/NixOS/nixpkgs/archive/haskell-updates.tar.gz should work.

[iblech]

Thank you, yes, I figured so. I love the prospect of requriring Agda urgently (I love that game so much), but in fact I'm not in a hurry. I just wanted to keep the [Agdapad](https://agdapad.quasicoherent.io/) up-to-date. :-)