/usr/lib/python2.7/dist-packages/flask_migrate/templates/flask/alembic.ini.mako is in python-flask-migrate 1.2.0-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/python2.7/dist-packages/flask_migrate/templates/flask/../../../../../../share/pyshared/flask_migrate/templates/flask/alembic.ini.mako