Hi, When we upgraded our Freebsd FreeBSD 8.2 to 9.0, we broke one of our python programs which use Pyro and depend on posix semaphores. Now when building python2.7.3 through ports, choosing the SEM option in make config and building, semaphores do not work although they worked on 8.2 with the same settings. In a jail: Code: # python Python 2.7.3 (default, May 7 2012, 18:16:58) [GCC 4.2.1 20070719 [FreeBSD]] on freebsd9 Type "help", "copyright", "credits" or "license" for more information. >>> from multiprocessing.queues import SimpleQueue Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/usr/local/lib/python2.7/multiprocessing/queues.py", line 48, in <module> from multiprocessing.synchronize import Lock, BoundedSemaphore, Semaphore, Condition File "/usr/local/lib/python2.7/multiprocessing/synchronize.py", line 59, in <module> " function, see issue 3770.") ImportError: This platform lacks a functioning sem_open implementation, therefore, the required synchronization primitives needed will not function, see issue 3770. I have in sysctl: Code: security.jail.sysvipc_allowed=1 It works out of jails. I have tried to tweak another jail security parameter: Code: security.jail.param.allow.sysvipc=1 but it does not help. I am also worried by the fact that some of my related sysctl settings do not seem to be taken into account: /etc/sysctl.conf: Code: p1003_1b.sem_nsems_max=1000 # sysctl p1003_1b.sem_nsems_max Code: p1003_1b.sem_nsems_max: 0 and: # sysctl p1003_1b.sem_nsems_max=1000 Code: p1003_1b.sem_nsems_max: 0 -> 0 (the-w option gives the same result).