anchor.diff:  
       inherit lcovExtraTraceFiles;
   
  +    postPhases = postPhases ++
  +      (stdenv.lib.optional doCoverageAnalysis "coverageReportPhase") ++ ["finalPhase"];
  +
       meta = (if args ? meta then args.meta else {}) // {
         description = if doCoverageAnalysis then "Coverage analysis" else "Native Nix build on ${stdenv.system}";
       };
  
positive.code:     dontInstall = doCoverageAnalysis;
  
      showBuildStats = true;
  
      postPhases =
        (stdenv.lib.optional doCoverageAnalysis "coverageReportPhase") ++ ["finalPhase"];
  
      finalPhase =
        ''
  
negative.code: , src, stdenv
  , name ? if doCoverageAnalysis then "nix-coverage" else "nix-build"
  , failureHook ? null
  , postPhases ? []
  , ... } @ args:
  
  stdenv.mkDerivation (
  