Dan Crosta

I think your test assertions are incorrect -- you're assigning a value to the `custom_pk` field, which is being "rewritten" to `_id` for storage in the database. This is a...

@gareth-lloyd sure, but issuing an update with `upsert=True` will still do the right thing, right? If there's a data loss or corruption issue here, let's identify the exact set of...

tox-docker 4.1.0 added support to build & use a Dockerfile in the repo. Does the [`USER`](https://docs.docker.com/engine/reference/builder/#user) command in a Dockerfile work for your needs here?

whoops, I forgot all about this, sorry! now that tox4 is (long since) out, I've published a regular release of tox-docker at https://pypi.org/project/tox-docker/4.0.0/, which should work with tox 3 and...

Can you say more about the use case here? I'm trying to understand how widespread this is, and whether there are any workarounds

This is superseded by #156, see note in #114

I believe this should be fixed in https://github.com/dcrosta/flask-pymongo/pull/164 ... can you test with that branch and let me know if this fixes the issue?