anchor.diff:        inherit
           gnumake gzip gnused bzip2 gawk ed xz patch bash python3
           ncurses libffi zlib gmp pcre gnugrep
  -        coreutils findutils diffutils patchutils ninja;
  +        coreutils findutils diffutils patchutils ninja libxml2;
   
         # Hack to make sure we don't link ncurses in bootstrap tools. The proper
         # solution is to avoid passing -L/nix-store/...-bootstrap-tools/lib,
  
positive.code:       llvmPackages_7 = super.llvmPackages_7 // (let
          tools = super.llvmPackages_7.tools.extend (llvmSelf: _: {
            clang-unwrapped = llvmPackages_7.clang-unwrapped.override { llvm = llvmSelf.llvm; };
            llvm = llvmPackages_7.llvm.override { libxml2 = self.darwin.libxml2-nopython; };
          });
          libraries = super.llvmPackages_7.libraries.extend (llvmSelf: _: {
            inherit (llvmPackages_7) libcxx libcxxabi compiler-rt;
  
negative.code:         inherit (darwin) dyld Libsystem libiconv locale;
  
          cctools = super.darwin.cctools.override { enableTapiSupport = false; };
          CF = super.darwin.CF.override {
            inherit libxml2;
            python3 = prevStage.python3;
          };
        };
  