Comment 2 for bug 1986696

For context, this is caused by the charms.templating.jinja2 python package, which pins charmhelpers to an older version[1] that's missing the tempita fix[2]. We fixed the same issue in some of our other charms by removing the charms.templating.jinja2 package requirement from them. We probably just need to do the same for Flannel.

[1]: https://github.com/juju-solutions/charms.templating.jinja2/blob/b958f36c20eb46ce1b589e7e7c7f7deef658289e/requirements.txt#L2
[2]: https://github.com/juju/charm-helpers/pull/674