anchor.diff:  
     src = fetchurl {
       urls = map (n: "${n}.xz") tarballUrls;
  -    hashOutput = true;
  -    sha256 = "1d62f8fa192f90e61c35a6fc15ff3cb9a7a792f782407acc42ef67817c5939f5";
  +    hashOutput = false;
  +    sha256 = "f346eeb90cce0910c05b877fe49eadc760fa084c0455fd313e39d4b2c2d4bb21";
     };
   
     nativeBuildInputs = [
  
positive.code: 
    buildInputs = [
      kmod
      zlib
    ];
  
    preBuild = ''
      makeFlagsArray+=(
        "SHARED=yes"
        "PREFIX=$out"
      )
    '';
  
    installTargets = [
      "install"
  
negative.code: , which
  
  , kmod
  , systemd_lib
  , zlib
  }:
  
  let
    name = "pciutils-3.5.6"; # with database from 2017-11
  
    tarballUrls = [
      "mirror://kernel/software/utils/pciutils/${name}.tar"
  