anchor.diff:  
   assert alsaSupport   -> alsaLib       != null;
   assert githubSupport -> curl          != null;
  -assert mpdSupport    -> libmpdclient != null;
  +assert mpdSupport    -> libmpdclient  != null;
   assert pulseSupport  -> libpulseaudio != null;
   
   assert iwSupport     -> ! nlSupport && wirelesstools != null;
  
positive.code: , pcre
  , pkg-config
  , python3
  , lib
  , stdenv
  , xcbproto
  
negative.code: 
  stdenv.mkDerivation rec {
      pname = "polybar";
      version = "3.5.5";
  
      src = fetchFromGitHub {
        owner = pname;
        repo = pname;
        rev = version;
        sha256 = "sha256-oRtTm5bXdL0C2WJsaK8H2Oc40DPWgAfjP7FgIHrpKGI=";
        fetchSubmodules = true;
      };
  
      nativeBuildInputs = [
        cmake
        pkg-config
        python3Packages.sphinx
        removeReferencesTo
  
        (if i3Support || i3GapsSupport then makeWrapper else null)
      ];
  
      buildInputs = [
        cairo
  