With non-nix systems, that's a fair point I guess session id might not be
supported (though if you're on a nix system my guess would be you're using
a proced format with session id omitted, in general the tests should guard
against this by setting the format for duration of the test).  I've
attached a new patch which makes the tests still check against PID, but
also makes the tests check if PPID matches as a fallback before failing.

Thanks, Laurence