anchor.diff:  in {
     check-nwc-health = generic {
       pname       = "check_nwc_health";
  -    version     = "20170804";
  -    rev         = "e959b412b5cf027c82a446668e026214fdcf8df3";
  -    sha256      = "11l74xw62g15rqrbf9ff2bfd5iw159gwhhgbkxwdqi8sp9j6navk";
  +    version     = "7.0.1.3";
  +    sha256      = "0rgd6zgd7kplx3z72n8zbzwkh8vnd83361sk9ibh6ng78sds1sl5";
       description = "Check plugin for network equipment.";
     };
   
     check-ups-health = generic {
       pname       = "check_ups_health";
  -    version     = "20170804";
  -    rev         = "32a8a359ea46ec0d6f3b7aea19ddedaad63b04b9";
  -    sha256      = "05na48dxfxrg0i9185j1ck2795p0rw1zwcs8ra0f14cm0qw0lp4l";
  +    version     = "2.8.2.2";
  +    sha256      = "1gc2wjsymay2vk5ywc1jj9cvrbhs0fs851x8l4nc75df2g75v521";
       description = "Check plugin for UPSs.";
     };
   }
  
positive.code: { stdenv, fetchFromGitHub, buildPerlPackage, autoreconfHook, makeWrapper
  , perl, NetSNMP, coreutils, gnused, gnugrep }:
  
  let
    owner = "lausser";
  
    glplugin = fetchFromGitHub {
      repo   = "GLPlugin";
      rev    = "b92a261ca4bf84e5b20d3025cc9a31ade03c474b";
      sha256 = "0kflnmpjmklq8fy2vf2h8qyvaiznymdi09z2h5qscrfi51xc9gmh";
      inherit owner;
    };
  
    generic = { pname, version, rev, sha256, description, ... } @ attrs:
    let
      attrs' = builtins.removeAttrs attrs [ "pname" "version" "rev" "sha256"];
    in perl.stdenv.mkDerivation rec {
      name = stdenv.lib.replaceStrings [ "-" ] [ "_" ] "${pname}-${version}";
  
      src = fetchFromGitHub {
        repo   = pname;
        inherit owner rev sha256;
      };
  
      buildInputs = [ perl NetSNMP ];
  
negative.code:     nativeBuildInputs = [ autoreconfHook makeWrapper ];
  
      prePatch = with stdenv.lib; ''
        rm -rf GLPlugin
        ln -s ${glplugin} GLPlugin
        substituteInPlace plugins-scripts/Makefile.am \
          --replace /bin/cat  ${getBin coreutils}/bin/cat \
          --replace /bin/echo ${getBin coreutils}/bin/echo \
  