anchor.diff:  }:
   
   stdenv.mkDerivation rec {
  -  version = "241.20190221";
  +  version = "242";
     name = "systemd-${version}";
   
     # When updating, use https://github.com/systemd/systemd-stable tree, not the development one!
  
positive.code:     owner = "NixOS";
      repo = "systemd";
      rev = "nixos-v${version}";
      sha256 = "0grcf0x793k1jx4bx7p63h3f3cd8w262824mzf8iwdsy6y9wzylr";
    };
  
    outputs = [ "out" "lib" "man" "dev" ];
  
negative.code:   # in a backwards-incompatible way.  If the interface version of two
    # systemd builds is the same, then we can switch between them at
    # runtime; otherwise we can't and we need to reboot.
    passthru.interfaceVersion = 3;
  
    meta = with stdenv.lib; {
      homepage = http://www.freedesktop.org/wiki/Software/systemd;
  