anchor.diff:  
       checkInputs = [
         coreutils
  -      (python3.withPackages(ps: [ps.pexpect]))
  +      (python3.withPackages (ps: [ ps.pexpect ]))
         procps
       ];
   
  
positive.code: 
    fish = stdenv.mkDerivation rec {
      pname = "fish";
      version = "3.2.0";
  
      src = fetchurl {
        # There are differences between the release tarball and the tarball GitHub
  
negative.code:       # --version`), as well as the local documentation for all builtins (and
        # maybe other things).
        url = "https://github.com/fish-shell/fish-shell/releases/download/${version}/${pname}-${version}.tar.xz";
        sha256 = "2OSfQJDTd43xfdgl5KKoAZIBVoJCPNndArZnXWXDr1s=";
      };
  
      # Fix FHS paths in tests
  