anchor.diff:  
     buildInputs = [ pkgconfig intltool file openssl curl libevent inotify-tools zlib ]
       ++ optionals enableGTK3 [ gtk3 makeWrapper ]
  -    ++ optional stdenv.isLinux systemd;
  +    ++ optionals enableSystemd [ systemd ]
   
     postPatch = ''
       substituteInPlace ./configure \
  
positive.code: { stdenv, fetchurl, pkgconfig, intltool, file, makeWrapper
  , openssl, curl, libevent, inotify-tools, systemd, zlib
  , enableGTK3 ? false, gtk3
  }:
  
  let
  
negative.code:       --replace "/usr/bin/file"     "${file}/bin/file"
    '';
  
    configureFlags = [
        "--enable-cli"
      ]
      ++ optional enableSystemd "--with-systemd-daemon"
      ++ optional enableGTK3 "--with-gtk";
  
    preFixup = optionalString enableGTK3 /* gsettings schemas for file dialogues */ ''
  