anchor.diff:  { stdenv, fetchurl, fetchpatch, lib, pkgconfig, utillinux, libcap, libtirpc, libevent
   , sqlite, kerberos, kmod, libuuid, keyutils, lvm2, systemd, coreutils, tcp_wrappers
   , python3, buildPackages, nixosTests
  +, enablePython ? true
   }:
   
   let
  
positive.code:         -e "s,/sbin/modprobe,${kmod}/bin/modprobe,g" \
          -e "s,/usr/sbin,$out/bin,g" \
          $out/etc/systemd/system/*
      '';
  
    # One test fails on mips.
  
negative.code:   buildInputs = [
      libtirpc libcap libevent sqlite lvm2
      libuuid keyutils kerberos tcp_wrappers
    ] ++ lib.optional enablePython python3;
  
    enableParallelBuilding = true;
  
  