anchor.diff:      '';
       homepage = http://coq.inria.fr;
       license = licenses.lgpl21;
  +    platforms = platforms.unix;
     };
   
   }
  
positive.code: , shell ? false
    # We don't use lib.inNixShell because that would also apply
    # when in a nix-shell of some package depending on this one.
  }:
  
  with pkgs;
  
negative.code: 
    installCheckTarget = [ "check" ];
  
    passthru = {
      inherit coq-version ocamlPackages;
      dontFilter = true; # Useful to use mkCoqPackages from <nixpkgs>
    };
  
    setupHook = writeText "setupHook.sh" "
      addCoqPath () {
        if test -d \"$1/lib/coq/${coq-version}/user-contrib\"; then
          export COQPATH=\"$COQPATH\${COQPATH:+:}$1/lib/coq/${coq-version}/user-contrib/\"
        fi
      }
  
      addEnvHooks \"$targetOffset\" addCoqPath
    ";
  
    meta = {
      description = "Coq proof assistant";
  