OpenIndiana failure looks like a resource management issue in ctypes:
======================================================================
FAIL: test_with_pip (test.test_venv.EnsurePipTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/export/home/buildbot/32bits/3.x.cea-indiana-x86/build/Lib/test/test_venv.py", line 304, in test_with_pip
    self.assertEqual(err, "")
AssertionError: "/export/home/buildbot/32bits/3.x.cea-ind[346 chars]):\n" != ''
- /export/home/buildbot/32bits/3.x.cea-indiana-x86/build/Lib/ctypes/util.py:179: ResourceWarning: unclosed file <_io.TextIOWrapper name=5 encoding='646'>
-   for line in os.popen(cmd).readlines():
- /export/home/buildbot/32bits/3.x.cea-indiana-x86/build/Lib/ctypes/util.py:179: ResourceWarning: unclosed file <_io.TextIOWrapper name=5 encoding='646'>
-   for line in os.popen(cmd).readlines():


Ubuntu LTS failure still puzzles me:

======================================================================
FAIL: test_with_pip (test.test_venv.EnsurePipTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/opt/python/3.x.langa-ubuntu/build/Lib/test/test_venv.py", line 289, in test_with_pip
    self.run_with_capture(venv.create, self.env_dir, with_pip=True)
subprocess.CalledProcessError: Command '['/tmp/tmpwsahapjn/bin/python', '-Im', 'ensurepip', '--upgrade', '--default-pip']' returned non-zero exit status 3

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/opt/python/3.x.langa-ubuntu/build/Lib/test/test_venv.py", line 295, in test_with_pip
    self.fail(msg)
AssertionError: Command '['/tmp/tmpwsahapjn/bin/python', '-Im', 'ensurepip', '--upgrade', '--default-pip']' returned non-zero exit status 3

**Subprocess Output**
Could not find an activated virtualenv (required).