TypeError: current() got an unexpected keyword argument 'head_only'

[mdantonio]

Alembic just released a new version (1.5.0) with the following breaking change:

Removed deprecated --head_only option to the alembic current command

Due to that Flask-Migrate no longer works with the following error:

TypeError: current() got an unexpected keyword argument 'head_only'

As a temporary workaround I simply installed alembic < 1.5.0

[miguelgrinberg]

2.6.0 released with this fix.

[mdantonio]

Just tested, thank you

[scuerda]

@miguelgrinberg Hey Miguel, just a heads up, but we just got burned by this in a bit of an unpleasant way. In setup.py you have 'alembic>=0.7'...we didn't have alembic pinned locally and as a result, when we re-computed out dependencies, installing flask-migrate 2.5.2 inadvertently upgraded us to 1.5.0. So folks ought to pin alembic specifically if they are using flask-migrate.

[miguelgrinberg]

@scuerda yes, the problem is that when the 2.5.2 release came out Alembic 1.5 did not exist yet, so I did not know that it was going to be incompatible and for that reason that release does not have a restriction on that alembic version.

In general I assume that you will be installing Flask-Migrate in one of these two scenarios:

• On a new project: you will be doing pip install flask-migrate, which will bring all the correct dependencies. You will then save your dependencies to a requirements.txt file.
• On an existing project: you will be doing pip install -r requirements.txt, which will bring all the correct dependencies that were saved by the first case.

You seem to be trying to use a third case that I have not really intended to support, which is to install an old release in a new project.

[scuerda]

@miguelgrinberg Totally fair point. I wasn't intending to suggest that there was work to do on your part for this. I wanted to describe my situation to leave some bread crumbs for anyone else who might get bit by letting their dependencies drift a bit.