Bug 1579432

Description of problem:

Python < 2.7.12 has a bug in its semaphore code that leads to errors when used with pid namespaces.

See: https://bugs.python.org/issue24303

This was fixed in 2.7.12 and 3.x, but RHEL 7 python still has this bug.


Version-Release number of selected component (if applicable):

2.7.5-68.el7.x86_64

How reproducible: 100%

Steps to Reproduce:
1. Run the following script

...
#!/bin/sh

for i in `seq 1 50`; do
  bwrap --unshare-uts --unshare-ipc --unshare-pid --proc /proc --dev-bind / / python -c "for i in range(500): import multiprocessing; print multiprocessing.Queue()" &
done | grep --line-buffered OSError
...

Actual results:

a smattering of:

```
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/usr/lib64/python2.7/multiprocessing/__init__.py", line 218, in Queue
    return Queue(maxsize)
  File "/usr/lib64/python2.7/multiprocessing/queues.py", line 68, in __init__
    self._wlock = Lock()
  File "/usr/lib64/python2.7/multiprocessing/synchronize.py", line 147, in __init__
    SemLock.__init__(self, SEMAPHORE, 1, 1)
  File "/usr/lib64/python2.7/multiprocessing/synchronize.py", line 75, in __init__
    sl = self._semlock = _multiprocessing.SemLock(kind, value, maxvalue)
OSError: [Errno 17] File exists
```

Expected results:

no errors

Additional info:

This is breaking Ansible Tower with a number of RHEL customers.