Sqlalchemy backend with AppendQuery fails

[jacobsantos]

TypeError: Mixer (<class 'app.models.Phone'>): 'object' object is not iterable.

Investigations suggest this has to do with sqlalchemy_continuum and the 'versions' attribute.

This should be a new ticket, but applying SKIP to the versions attribute does nothing or that is to say, that the failure is something else entirely. It still appears to attempt to set the SKIP attribute, which is counterintuitive at best and a possible bug.

[jacobsantos]

I have solved this locally by simply try... excepting TypeError line 70 of mixer/backend/sqlalchemy.py