[Bug 1445764] Re: "The executable /usr/bin/python3.4 does not exist" error when Installing Mailman 3 on Centos 7

There is something wrong with your Python 3.4.

What happens if you just do

$ /usr/local/bin/python3.4

...

...

import os import _collections_abc

and

$ /usr/local/src/mailman-bundler/venv-3.4/lib/python3.4

...

...

import os import _collections_abc

I suspect you will get ImportError on all of those which means your Python 3.4 install is broken. You need to have a working Python 3.4 that can successfully

import os