anchor.diff:  
     preConfigure = ''
       mesonFlagsArray+=(-Dntp-servers="0.nixos.pool.ntp.org 1.nixos.pool.ntp.org 2.nixos.pool.ntp.org 3.nixos.pool.ntp.org")
  -    mesonFlagsArray+=(-Ddbuspolicydir=$out/etc/dbus-1/system.d)
  -    mesonFlagsArray+=(-Ddbussessionservicedir=$out/share/dbus-1/services)
  -    mesonFlagsArray+=(-Ddbussystemservicedir=$out/share/dbus-1/system-services)
  -    mesonFlagsArray+=(-Dpamconfdir=$out/etc/pam.d)
  -    mesonFlagsArray+=(-Drootprefix=$out)
  -    mesonFlagsArray+=(-Drootlibdir=$lib/lib)
  -    mesonFlagsArray+=(-Dpkgconfiglibdir=$dev/lib/pkgconfig)
  -    mesonFlagsArray+=(-Dpkgconfigdatadir=$dev/share/pkgconfig)
  -
       export LC_ALL="en_US.UTF-8";
       # FIXME: patch this in systemd properly (and send upstream).
       # already fixed in f00929ad622c978f8ad83590a15a765b4beecac9: (u)mount
  
positive.code: , withKexectools ? lib.any (lib.meta.platformMatch stdenv.hostPlatform) kexectools.meta.platforms, kexectools
  }:
  
  let
    pythonLxmlEnv = buildPackages.python3Packages.python.withPackages ( ps: with ps; [ python3Packages.lxml ]);
  
  in stdenv.mkDerivation rec {
    version = "239.20190219";
    name = "systemd-${version}";
  
    # When updating, use https://github.com/systemd/systemd-stable tree, not the development one!
  
negative.code:       coreutils # meson calls date, stat etc.
        glibcLocales
        patchelf getent m4
  
        (buildPackages.python3Packages.python.withPackages ( ps: with ps; [ python3Packages.lxml ]))
      ];
    buildInputs =
      [ linuxHeaders libcap kmod xz pam acl
  