Ubuntu Blender Installation, Python sys.path broken I have installed blender on three Ubuntu machines using the following commands:

sudo add-apt-repository ppa:thomas-schiex/blender
sudo apt-get update &amp;&amp; sudo apt-get install blender


according to this (http://ubuntuhandbook.org/index.php/2016/10/install-blender-2-78-in-ubuntu-16-04-14-04/)

Note that these are networked machines that I only have command line access to. Two of them work perfectly and one raises the following error when trying to import numpy in a blender script:

  File "/usr/lib/python3/dist-packages/numpy/core/__init__.py", line 6, in &lt;module&gt;
from . import multiarray
ImportError: cannot import name 'multiarray'


To diagnose this I have printed the sys.path of blender python on the machines that work, and get this:

&gt;&gt;&gt; for p in sys.path:
...     print(p)
/usr/lib/blender/2.79/scripts/addons_contrib
/usr/lib/blender/2.79/scripts/addons
/usr/lib/blender/2.79/scripts/startup
/usr/lib/blender/2.79/scripts/modules
/usr/lib/blender/2.79/python/lib/python35.zip
/usr/lib/blender/2.79/python/lib/python3.5
/usr/lib/blender/2.79/python/lib/python3.5/plat-linux
/usr/lib/blender/2.79/python/lib/python3.5/lib-dynload
/usr/lib/blender/2.79/python/lib/python3.5/site-packages
/usr/lib/blender/2.79/scripts/freestyle/modules
/usr/lib/blender/2.79/scripts/addons/modules


On the machine that is failing to import numpy, the blender python sys.path is:

&gt;&gt;&gt; for p in sys.path:
...     print(p)
/usr/share/blender/2.79/scripts/addons_contrib
/usr/share/blender/2.79/scripts/addons
/usr/share/blender/2.79/scripts/startup
/usr/share/blender/2.79/scripts/modules
/usr/lib/python36.zip
/usr/lib/python3.6
/usr/lib/python3.6/lib-dynload
/usr/lib/python3/dist-packages
/usr/share/blender/2.79/scripts/freestyle/modules
/usr/share/blender/2.79/scripts/addons/modules


So, for some reason, when I install blender, on this machine, it is using an external python3.6, when it should be using the python3.5 that is packaged with blender. Note that I can't even find a python directory in the installed blender. I have uninstalled, and reinstalled, My python path is unset. How can I diagnose and fix the blender installation on this machine?
We can't support unofficial builds, as there are too many of them with too many unknowns. If you really want to use this PPA, ask the person who created it for help. If you just want to use Blender on Ubuntu, download the Linux version from the Blender download page.