I encountered similar issues to those discussed in this issue whilst compiling 3.4.1 on 'Red Hat Enterprise Linux Server release 6.5 (Santiago)'

In particular, the following tests were failing -

[root@lonlx90800 ~]# /local/0/python-3.4.1/bin/python3 /local/0/python-3.4.1/lib/python3.4/test/test_asyncio/test_subprocess.py
F.......F.......
======================================================================
FAIL: test_broken_pipe (__main__.SubprocessFastWatcherTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/local/0/python-3.4.1/lib/python3.4/test/test_asyncio/test_subprocess.py", line 129, in test_broken_pipe
    self.loop.run_until_complete(proc.communicate(large_data))
AssertionError: BrokenPipeError not raised

======================================================================
FAIL: test_broken_pipe (__main__.SubprocessSafeWatcherTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/local/0/python-3.4.1/lib/python3.4/test/test_asyncio/test_subprocess.py", line 129, in test_broken_pipe
    self.loop.run_until_complete(proc.communicate(large_data))
AssertionError: BrokenPipeError not raised

In this case, the issues are being caused by the following kernel parameters that we have for our default build -

#########################
## TIBCO network tuning #
#########################
net.core.rmem_default = 33554432
net.core.wmem_default = 33554432
net.core.rmem_max = 33554432
net.core.wmem_max = 33554432

Toggling the support.PIPE_MAX_SIZE to +32MB or temporarily removing these parameters mitigates the issue.  Is there a better way of calculating support.PIPE_MAX_SIZE so it is reflective of the actual OS value?