Error during setup: ImportError: No module named collections_abc

[HollywoodMarks]

Received the following error during setup on Ubuntu 18, when trying to install the MHN server:

• /usr/local/bin/virtualenv -p /usr/bin/python env
  Traceback (most recent call last):
  File "/usr/local/bin/virtualenv", line 5, in
  from virtualenv.main import run_with_catch
  File "/usr/local/lib/python2.7/dist-packages/virtualenv/init.py", line 3, in
  from .run import cli_run, session_via_cli
  File "/usr/local/lib/python2.7/dist-packages/virtualenv/run/init.py", line 7, in
  from ..app_data import make_app_data
  File "/usr/local/lib/python2.7/dist-packages/virtualenv/app_data/init.py", line 12, in
  from .read_only import ReadOnlyAppData
  File "/usr/local/lib/python2.7/dist-packages/virtualenv/app_data/read_only.py", line 3, in
  from virtualenv.util.lock import NoOpFileLock
  File "/usr/local/lib/python2.7/dist-packages/virtualenv/util/lock.py", line 13, in
  from virtualenv.util.path import Path
  File "/usr/local/lib/python2.7/dist-packages/virtualenv/util/path/init.py", line 3, in
  from ._pathlib import Path
  File "/usr/local/lib/python2.7/dist-packages/virtualenv/util/path/_pathlib/init.py", line 14, in
  from pathlib2 import Path
  File "/usr/local/lib/python2.7/dist-packages/pathlib2/init.py", line 26, in
  from six.moves.collections_abc import Sequence
  ImportError: No module named collections_abc

[HollywoodMarks]

/opt/mhn/server$ virtualenv --version
virtualenv 20.13.1 from /usr/local/lib/python2.7/dist-packages/virtualenv/init.pyc

[GryphonInfoSec]

This is due to an older version of virtualenv requirement. pip version breaks the install. do a pip uninstall and use apt instead.
sudo apt install python-virtualenv