anchor.diff:      # This might not hold for e.g. BSD.
       "--with-sysdep-devurandom=yes"
       (if stdenv.isDarwin
  -      then "--disable-shared"
  -      else "--enable-shared")
  +    then "--disable-shared"
  +    else "--enable-shared")
     ]
       # On darwin, the target triplet from -dumpmachine includes version number,
       # but skarnet.org software uses the triplet to test binary compatibility.
  
positive.code:     # binary built on a different version of darwin.
      # http://www.skarnet.org/cgi-bin/archive.cgi?1:mss:623:heiodchokfjdkonfhdph
      ++ (lib.optional stdenv.isDarwin
           "--build=${stdenv.hostPlatform.system}");
  
    inherit postConfigure;
  
    makeFlags = lib.optional stdenv.cc.isClang [ "AR=${stdenv.cc.targetPrefix}ar" "RANLIB=${stdenv.cc.targetPrefix}ranlib" ];               
  
    # TODO(Profpatsch): ensure that there is always a $doc output!
    postInstall = ''
  
negative.code:   # : lines
  , postInstall
    # : list Maintainer
  , maintainers ? [ ]
    # : passtrhu arguments (e.g. tests)
  , passthru ? { }
  
  }:
  
  