CKAN version

2.11

Describe the bug

I got a clean install of 2.11.
The database migration 4eaa5fcf3092 removes resource_revision, which is necessary by ckanext-harvester.
The harvester function seems to work fine until the clear function is called.
There the havester extension tries to delete entries in the resource_revision table.

Additionally a downgrade is not possible:
sqlalchemy.exc.CompileError: Can't emit DROP CONSTRAINT for constraint ForeignKeyConstraint(<sqlalchemy.sql.base.DedupeColumnCollection object at 0x79ab9b1cb750>, None, table=Table('resource', MetaData(), schema=None)); it has no name

Steps to reproduce

Steps to reproduce the behavior:

1. Add a harvester source
2. Try to clear the harvester source

Expected behavior

Working clearance of the harvester data.
Functional downgrade.

Additional details

https://github.com/search?q=repo%3Ackan%2Fckanext-harvest%20resource_revision&type=code