anchor.diff:  { stdenv, lib, fetchFromGitHub, python, makeWrapper
  -, eigen, fftw, libtiff, zlib, ants, bc
  +, eigen, fftw, libtiff, libpng, zlib, ants, bc
   , qt5, libGL, libGLU, libX11, libXext
   , withGui ? true }:
   
   stdenv.mkDerivation rec {
     pname = "mrtrix";
  -  version = "3.0_RC3_latest";
  +  version = "3.0.0";
   
     src = fetchFromGitHub {
       owner  = "MRtrix3";
       repo   = "mrtrix3";
       rev    = version;
  -    sha256 = "184nv524p8j94qicjy9l288bqcgl2yxqqs55a7042i0gfsnwp51c";
  +    sha256 = "1vvmmbw3m0bdfwp4szr62ygzsvkj0ss91cx5zlkspsr1rff05f9b";
       fetchSubmodules = true;
     };
   
  
positive.code:     python
      fftw
      libtiff
      zlib ] ++ lib.optionals withGui [
      libGL
      libGLU
      libX11
  
negative.code: 
    postInstall = ''
      for prog in $out/bin/*; do
        if [[ -x "$prog" ]]; then
          wrapProgram $prog --prefix PATH : ${lib.makeBinPath [ ants ]}
        fi
      done
    '';
  
  