Motivation for this change

On 2021-06-10, stackage bumped the random library from 1.1 to 1.2.0. Unfortunately this breaks xmonad-wallpaper, as that library has a bound limit of random >=1.1 && <1.2.

Things done

Fortunately, xmonad-wallpaper builds just fine with random-1.2.0. I have tested building the package both by editing the cabal file directly and with my changes here via:

nix-build --no-out-link A haskellPackages.xmonad-wallpaper --arg config '{ allowBroken = true; }'

I'm currently attempting to rebuild my system with my version of nixpkgs, but this takes a very long time 😉. Previously my builds failed in under a minute due to the error:

Setup: Encountered missing or private dependencies:
random ==1.1.*

So this looks promising to me.

I contacted xmonad-wallpaper's maintainer about increasing the bound on hackage, as that's probably the right thing to do and would make this whole exercise unnecessary. Still, I made this PR in case we want to provide a quicker workaround (it would at least be useful for me, as I can't update nixpkgs until this is fixed). But I will, of course, defer to whatever the reviewers think is the best course of action. If this fix is merged, I can make a second PR once the package on hackage is updated.

Thanks!

• 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/)
• 21.11 Release Notes
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
• Fits CONTRIBUTING.md.