Good afternoon, I ran into an issue while trying to deploy Airflow using a MS-SQL 2012 backend. Two alembic migrations were causing the issue: e3a246e0dc1_current_schema.py and 1507a7289a2f_create_is_encrypted.py.
It seems that by using separate engine instances, that the inspector object and the op object were causing each others' queries to block. Once I switched the engine that the inspector was using from settings.engine to op.get_bind() the migrations completed successfully. I couldn't find any issues surrounding this problem in Jira to reference along with a PR, and it doesn't seem that just anyone can create an issue, but I'll submit my fix as a PR if anyone thinks it would be of value. I'm just not sure how to proceed. Thanks, Chad Henderson
