anchor.diff:  let
   
     inherit (releng_pkgs.lib) mkTaskclusterHook mkTaskclusterMergeEnv mkPython fromRequirementsFile filterSource mkRustPlatform;
  -  inherit (releng_pkgs.pkgs) writeScript makeWrapper fetchurl cacert git llvm_7 libxml2;
  +  inherit (releng_pkgs.pkgs) writeScript makeWrapper fetchurl cacert git libxml2;
     inherit (releng_pkgs.pkgs.stdenv) mkDerivation;
     inherit (releng_pkgs.pkgs.lib) fileContents optional licenses;
     inherit (releng_pkgs.tools) pypi2nix mercurial ;
  
positive.code:       owner = "marco-c";
        repo = "grcov";
        rev = "v${version}";
        sha256 = "1b43pdi00bkpa7pii2hnasml208581ygmspqr7gpq186k7cil8x0";
      };
  
  	# ...
  
negative.code: 
    # Marco grcov
    grcov = rustPlatform.buildRustPackage rec {
      version = "0.4.0";
      name = "grcov-${version}";
  
      buildInputs = [
          libxml2
      ];
  
  