[Python-Dev] Failures in test_site.py - how to debug?

[Steve Dower]

On 19Aug2016 0910, Chris Angelico wrote:
> On Sat, Aug 20, 2016 at 1:26 AM, Steve Dower <steve.dower at python.org> wrote:
>> Check any .pth files you can find. I suspect mpl_toolkits has some magic in
>> it to make the namespace package work on 2.7.
>
> $ cat /usr/local/lib/python3.6/site-packages/matplotlib-1.5.1-py3.6-nspkg.pth
> import sys, types, os;p =
> os.path.join(sys._getframe(1).f_locals['sitedir'],
> *('mpl_toolkits',));ie =
> os.path.exists(os.path.join(p,'__init__.py'));m = not ie and
> sys.modules.setdefault('mpl_toolkits',
> types.ModuleType('mpl_toolkits'));mp = (m or []) and
> m.__dict__.setdefault('__path__',[]);(p not in mp) and mp.append(p)
>
> Is it possible that that's the cause? And if so, should "python -I"
> remove /usr/local/lib/python3.6/site-packages from sys.path?

That explains the extra modules - types.py imports collections and 
collections.abc, which would seem to account for the rest.

I'm not sure whether that's causing the problem or not, but temporarily 
renaming that pth file so it isn't picked up may help you track down the 
test issue.

"python -S" is the only way to avoid .pth files, but that's a pretty 
heavy hammer.

Cheers,
Steve