anchor.diff:  
     rspamd = callPackage ../servers/mail/rspamd { };
   
  -  pfixtools = callPackage ../servers/mail/postfix/pfixtools.nix { };
  +  pfixtools = callPackage ../servers/mail/postfix/pfixtools.nix {
  +    gperf = gperf_3_0;
  +  };
     pflogsumm = callPackage ../servers/mail/postfix/pflogsumm.nix { };
   
     postgrey = callPackage ../servers/mail/postgrey { };
  
positive.code: 
    jenkins-job-builder = pythonPackages.jenkins-job-builder;
  
    kconfig-frontends = callPackage ../development/tools/misc/kconfig-frontends { };
  
    kcov = callPackage ../development/tools/analysis/kcov { };
  
  
negative.code: 
    bibletime = callPackage ../applications/misc/bibletime { };
  
    bitkeeper = callPackage ../applications/version-management/bitkeeper {
      gperf = gperf_3_0;
    };
  
    bitlbee = callPackage ../applications/networking/instant-messengers/bitlbee { };
    bitlbee-plugins = callPackage ../applications/networking/instant-messengers/bitlbee/plugins.nix { };
  