anchor.diff:      owner = "gillesdegottex";
     };
   
  -  buildInputs = [ alsaLib fftw freeglut libjack2 qt5Full ];
  +  buildInputs = [ fftw freeglut qt5Full ]
  +    ++ stdenv.lib.optional alsaSupport [ alsaLib ]
  +    ++ stdenv.lib.optional jackSupport [ libjack2 ];
   
     postPatch = ''
       substituteInPlace fmit.pro --replace '$$FMITVERSIONGITPRO' '${version}'
  
positive.code:   '';
  
    configurePhase = ''
      qmake CONFIG+="acs_alsa acs_jack" fmit.pro
    '';
  
    enableParallelBuilding = true;
  
negative.code: # FIXME: upgrading qt5Full (Qt 5.3) to qt5.{base,multimedia} (Qt 5.4) breaks
  # the default Qt audio capture source!
  { stdenv, fetchFromGitHub, fftw, freeglut, qt5Full
  , alsaSupport ? false, alsaLib ? null
  , jackSupport ? false, libjack2 ? null }:
  
  assert alsaSupport -> alsaLib != null;
  assert jackSupport -> libjack2 != null;
  
  let version = "1.0.5"; in
  stdenv.mkDerivation {
  