anchor.diff:  
     cmakeFlags = [
       "-DSLIC3R_FHS=1"
  -    "-DSLIC3R_WX_STABLE=1"  # necessary when compiling against wxGTK 3.0
     ];
   
     postInstall = ''
  
positive.code:     glew
      libpng
      tbb
      wxGTK30
      xorg.libX11
    ] ++ checkInputs;
  
  
negative.code: { stdenv, lib, fetchFromGitHub, makeWrapper, cmake, pkgconfig
  , boost, cereal, curl, eigen, expat, glew, libpng, tbb, wxGTK31
  , gtest, nlopt, xorg, makeDesktopItem
  }:
  let
  