I have checked in some libc changes with this log entry: 1999-09-17 Roland McGrath <email@example.com> * hurd/port2fd.c (_hurd_port2fd): Never change CTTYID port. * sysdeps/mach/hurd/setsid.c (__setsid): Fix return type -> pid_t. Return _hurd_pgrp instead of 0. Please let me know if that fixes the setsid problem for you or not. I have not had a chance to test it yet.