anchor.diff:      "${boolNo mumbleOverlay}overlay"
       "no-qt4-legacy-compat"
     ] ++ optionals (config == "murmur") [
  -    "no-ice"
  +    "${boolNo (ice != null)}ice"
       "${boolNo (grpc != null)}grpc"
       "qssldiffiehellmanparameters"
     ];
  
positive.code: , boost
  , fixesproto
  , grpc
  , inputproto
  , jack2_lib
  , libcap
  
negative.code:   postPatch = optionalString (config == "mumble") ''
      export MUMBLE_PYTHON="${python2}/bin/python"
      patchShebangs ./scripts/rcc-depends.py
    '' + optionalString (config == "murmur" && ice != null) ''
      sed -i 's,/usr,${ice},g' src/murmur/murmur_ice/murmur_ice.pro
    '';
  
    configureFlags = [
  