The line "from . import exceptions" of urllib3 failed:
https://github.com/shazow/urllib3/blob/master/urllib3/__init__.py#L22

It is strange because urllib3/exceptions.py is part of the urllib3 module.

http://buildbot.python.org/all/builders/AMD64%20Fedora%20without%20threads%203.x/builds/5674/steps/test/logs/stdio

======================================================================
FAIL: test_with_pip (test.test_venv.EnsurePipTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/buildbot/buildarea/3.x.krah-fedora/build/Lib/test/test_venv.py", line 299, in test_with_pip
    self.run_with_capture(venv.create, self.env_dir, with_pip=True)
subprocess.CalledProcessError: Command '['/tmp/tmpd8r2w88y/bin/python', '-Im', 'ensurepip', '--upgrade', '--default-pip']' returned non-zero exit status 1

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/buildbot/buildarea/3.x.krah-fedora/build/Lib/test/test_venv.py", line 305, in test_with_pip
    self.fail(msg)
AssertionError: Command '['/tmp/tmpd8r2w88y/bin/python', '-Im', 'ensurepip', '--upgrade', '--default-pip']' returned non-zero exit status 1

**Subprocess Output**
Traceback (most recent call last):
  File "/home/buildbot/buildarea/3.x.krah-fedora/build/Lib/runpy.py", line 160, in _run_module_as_main
    "__main__", fname, loader, pkg_name)
  File "/home/buildbot/buildarea/3.x.krah-fedora/build/Lib/runpy.py", line 73, in _run_code
    exec(code, run_globals)
  File "/home/buildbot/buildarea/3.x.krah-fedora/build/Lib/ensurepip/__main__.py", line 66, in <module>
    main()
  File "/home/buildbot/buildarea/3.x.krah-fedora/build/Lib/ensurepip/__main__.py", line 61, in main
    default_pip=args.default_pip,
  File "/home/buildbot/buildarea/3.x.krah-fedora/build/Lib/ensurepip/__init__.py", line 92, in bootstrap
    _run_pip(args + [p[0] for p in _PROJECTS], additional_paths)
  File "/home/buildbot/buildarea/3.x.krah-fedora/build/Lib/ensurepip/__init__.py", line 28, in _run_pip
    import pip
  File "/tmp/tmpwzs5sx88/pip-1.5.rc1-py2.py3-none-any.whl/pip/__init__.py", line 11, in <module>
  File "/tmp/tmpwzs5sx88/pip-1.5.rc1-py2.py3-none-any.whl/pip/vcs/mercurial.py", line 9, in <module>
  File "/tmp/tmpwzs5sx88/pip-1.5.rc1-py2.py3-none-any.whl/pip/download.py", line 22, in <module>
  File "/tmp/tmpwzs5sx88/pip-1.5.rc1-py2.py3-none-any.whl/pip/_vendor/requests/__init__.py", line 58, in <module>
  File "/tmp/tmpwzs5sx88/pip-1.5.rc1-py2.py3-none-any.whl/pip/_vendor/requests/utils.py", line 24, in <module>
  File "/tmp/tmpwzs5sx88/pip-1.5.rc1-py2.py3-none-any.whl/pip/_vendor/requests/compat.py", line 7, in <module>
  File "/tmp/tmpwzs5sx88/pip-1.5.rc1-py2.py3-none-any.whl/pip/_vendor/requests/packages/__init__.py", line 3, in <module>
  File "/tmp/tmpwzs5sx88/pip-1.5.rc1-py2.py3-none-any.whl/pip/_vendor/requests/packages/urllib3/__init__.py", line 22, in <module>
ImportError: cannot import name 'exceptions'

Potentially another platform compatibility issue for pip's dependencies.

In fact, it's an issue in the urllib3 library which require threads.

$ cd /home/haypo/pip/PIP/pip/_vendor/requests/packages
$ /home/haypo/prog/python/default/venv/bin/python -c 'import urllib3'
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/home/haypo/pip/PIP/pip/_vendor/requests/packages/urllib3/__init__.py", line 24, in <module>
    from .poolmanager import PoolManager, ProxyManager, proxy_from_url
  File "/home/haypo/pip/PIP/pip/_vendor/requests/packages/urllib3/poolmanager.py", line 14, in <module>
    from ._collections import RecentlyUsedContainer
  File "/home/haypo/pip/PIP/pip/_vendor/requests/packages/urllib3/_collections.py", line 8, in <module>
    from threading import RLock
  File "/home/haypo/prog/python/default/Lib/threading.py", line 4, in <module>
    import _thread
ImportError: No module named '_thread'

Here is a patch for urllib3.

I reported the issue upstream:
https://github.com/shazow/urllib3/issues/289

Cool, my patch was already applied upstream:

https://github.com/shazow/urllib3/commit/929f15866e62d02a0249284cf54d1b8b6441505a

@Nick: can you try to package a new wheel package for pip?

The urllib3 in requests VCS was updated, I just need to bother Kenneth to make a new release of requests or update pip to an unreleased requests.

Issue 19924 suggests we may need a new distlib as well

Requests was released and pip updated it, I can release a new pip but it appears that perhaps distlib needs fixed before the without threads case is taken care of?

I will look at doing a distlib update shortly - but there's another issue (#19913) that might also require an update - it' not clear yet.

I've updated distlib to use dummy_threading where threading isn't available - see

https://bitbucket.org/pypa/distlib/commits/029fee573900765729402203e39b2171d7ae0784

Can someone please test with this version vendored into pip to check that the failures no longer occur in a no-thread environment, before I do a distlib release?

Vinay, thanks for your fast response! :) #19913 should be resolved, too. A couple of months ago several people complained about a new file that looked like a ZIP bomb. This virus warnings looks even more severe although it's probably a false positive. Could you try a new set of binaries without UPX? https://www.virustotal.com/ lets you scan the files with more than 40 programs at once and for free.

This commit in distlib uses uncompressed launcher executables which pass the virustotal.com checks:

https://bitbucket.org/pypa/distlib/commits/e23c9e4fd3125fa88063de4dec80367b1ac82aff

Vinay, I've verified that the current default branch of distlib works without threading when vendored in pip and these tests pass.

I've released distlib 0.1.5 on PyPI. This release uses dummy_threading when threading isn't available.

Not quite fixed yet - Donald, I think all the vendored dependencies have been updated now, would it be possible to spin and incorporate a pip 1.5rc2 somewhat soonish so we know what's still left to be addressed on the ensurepip side?

Donald updated CPython to pip 1.5rc2, so test_venv is now passing without threading support:

http://buildbot.python.org/all/builders/AMD64%20Fedora%20without%20threads%203.x/builds/5874/steps/test/logs/stdio