Emanuel, sorry, I missed the request for sys.version earlier.

The tempfile.py I attached earlier is from the python 3.5 pulled from a ppa. I wouldn't be surprised if it has some patches applied by debian/ubuntu. To be clear though the problem also presents itself with a python 3.5 I compiled. The Vagrantfile in the github repository shows exactly how I compiled it.

Here it is from the version from the ppa:

Python 3.5.0 (default, Sep 17 2015, 00:00:00) 
[GCC 4.8.4] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> sys.version
'3.5.0 (default, Sep 17 2015, 00:00:00) \n[GCC 4.8.4]'
>>> sys.implementation
namespace(_multiarch='x86_64-linux-gnu', cache_tag='cpython-35', hexversion=50659568, name='cpython', version=sys.version_info(major=3, minor=5, micro=0, releaselevel='final', serial=0))


Here are the same for the version I compiled:
vagrant@vagrant-ubuntu-trusty-64:~$ python3.5
Python 3.5.0 (default, Nov 24 2015, 19:50:42) 
[GCC 4.8.4] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> sys.version
'3.5.0 (default, Nov 24 2015, 19:50:42) \n[GCC 4.8.4]'
>>> sys.implementation
namespace(cache_tag='cpython-35', hexversion=50659568, name='cpython', version=sys.version_info(major=3, minor=5, micro=0, releaselevel='final', serial=0))