undefined symbol: _Py_RefTotal

[Jay R. Wren]

snapcraft v. 2.27.1

python2 module.

snapcraft.yaml like this:

parts:
  charm-tools:
    source: https://github.com/juju/charm-tools.git
    source-tag: v2.2.0
    plugin: python
    python-version: python3
    build-packages:
      - build-essential
      - python3-dev
    python-packages:
        - urllib3
        - simplejson
    stage-packages:
      - git
      - bzr
      - mercurial

The Cheetah python package builds a C module Cheetah._namemapper.so.

This C module claims undefined symbols when loading in snap context:

ImportError: /snap/charm/x5/lib/python2.7/site-packages/Cheetah/_namemapper.so: undefined symbol: _Py_RefTotal

Does the python plugin support C modules with python-version set to python2?