Tried strace, this is what I’m seeing so far:
91 10:02:03 semop(9, [{0, -1, SEM_UNDO|IPC_NOWAIT}], 1 <unfinished ...>
56 10:02:03 <... select resumed>) = 0 (Timeout)
83 10:02:03 semop(9, [{0, -1, SEM_UNDO|IPC_NOWAIT}], 1 <unfinished ...>
55 10:02:03 semop(9, [{0, -1, SEM_UNDO|IPC_NOWAIT}], 1 <unfinished ...>
91 10:02:03 <... semop resumed>) = -1 EAGAIN (Resource temporarily unavailable)
83 10:02:03 <... semop resumed>) = -1 EAGAIN (Resource temporarily unavailable)
56 10:02:03 semop(9, [{0, -1, SEM_UNDO|IPC_NOWAIT}], 1 <unfinished ...>
47 10:02:03 semop(9, [{0, -1, SEM_UNDO|IPC_NOWAIT}], 1 <unfinished ...>
29 10:02:03 <... select resumed>) = 0 (Timeout)
91 10:02:03 select(0, NULL, NULL, NULL, {tv_sec=0, tv_usec=100000} <unfinished ...>
83 10:02:03 select(0, NULL, NULL, NULL, {tv_sec=0, tv_usec=100000} <unfinished ...>
56 10:02:03 <... semop resumed>) = -1 EAGAIN (Resource temporarily unavailable)
55 10:02:03 <... semop resumed>) = -1 EAGAIN (Resource temporarily unavailable)
47 10:02:03 <... semop resumed>) = -1 EAGAIN (Resource temporarily unavailable)
56 10:02:03 select(0, NULL, NULL, NULL, {tv_sec=0, tv_usec=100000} <unfinished ...>
55 10:02:03 select(0, NULL, NULL, NULL, {tv_sec=0, tv_usec=100000} <unfinished ...>
29 10:02:03 semop(9, [{0, -1, SEM_UNDO|IPC_NOWAIT}], 1 <unfinished ...>
47 10:02:03 select(0, NULL, NULL, NULL, {tv_sec=0, tv_usec=100000} <unfinished ...>
29 10:02:03 <... semop resumed>) = -1 EAGAIN (Resource temporarily unavailable)
29 10:02:03 select(0, NULL, NULL, NULL, {tv_sec=0, tv_usec=100000} <unfinished ...>
22 10:02:03 <... select resumed>) = 0 (Timeout)
22 10:02:03 select(0, NULL, NULL, NULL, {tv_sec=0, tv_usec=100000} <unfinished ...>
117 10:02:03 <... select resumed>) = 0 (Timeout)
117 10:02:03 semop(9, [{0, -1, SEM_UNDO|IPC_NOWAIT}], 1) = -1 EAGAIN (Resource temporarily unavailable)
117 10:02:03 select(0, NULL, NULL, NULL, {tv_sec=0, tv_usec=100000} <unfinished ...>
Which, who knows what that means?!?