anchor.diff: -{ stdenv, fetchFromGitHub, python, llvm, clang }:
  +{ stdenv, fetchFromGitHub, python2, llvm, clang }:
   
   stdenv.mkDerivation {
     name = "libclc-2015-08-07";
  
positive.code:     sha256 = "10n9qk1dild9yjkjjkzpmp9zid3ysdgvqrad554azcf755frch7g";
    };
  
    buildInputs = [ python llvm clang ];
  
    postPatch = ''
      sed -i 's,llvm_clang =.*,llvm_clang = "${clang}/bin/clang",' configure.py
  
negative.code:   '';
  
    configurePhase = ''
      ${python.interpreter} ./configure.py --prefix=$out
    '';
  
    meta = with stdenv.lib; {
  