Python, SQLAlchemy, Pytest, PyCharm Debugger & NoSuchColumnError

There is this error when I use PyCharm debugger during pytest.

NoSuchColumnError: "Could not locate column in row for column ''"

This is a SQLAlchemy error. No useful help on Google. No error if the breakpoints are muted. Therefore, it is possibly related to lazy loading of relationships when displaying variables.

This can be resolved by turning off the “load values asynchronously” option in PyCharm debugger. As far as I can remember, this is a new feature in PyCharm 2017.3. Not sure whether this is related to gevent.