anchor.diff: -{ lib, stdenv, llvm_meta, src, cmake, libxml2, libllvm, version, python3
  +{ lib, stdenv, llvm_meta, src, substituteAll, cmake, libxml2, libllvm, version, python3
   , buildLlvmTools
   , fixDarwinDylibNames
   , enableManpages ? false
  
positive.code:       ./purity.patch
        # https://reviews.llvm.org/D51899
        ./gnu-install-dirs.patch
      ];
  
      postPatch = ''
  
negative.code: 
      outputs = [ "out" "lib" "dev" "python" ];
  
      postInstall = ''
        ln -sv $out/bin/clang $out/bin/cpp
  
        # Move libclang to 'lib' output
  