Wikimedia Bugzilla is closed!

When a cohort is tagged and I try to delete it, the following flash message appears:

"Error! Wikimetrics is experiencing problems. Visit the Support page for help if this persists. You can also check the console for details."

Here is the server error:

IntegrityError: (IntegrityError) (1451, 'Cannot delete or update a parent row: a foreign key constraint fails (`wikimetrics`.`cohort_tag`, CONSTRAINT `cohort_tag_ibfk_1` FOREIGN KEY (`cohort_id`) REFERENCES `cohort` (`id`))') 'DELETE FROM cohort WHERE cohort.id = %s' (21,)


And here is the full stack trace:

10.0.2.2 - - [23/Oct/2014 17:04:46] "POST /cohorts/delete/21 HTTP/1.1" 500 -
Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1836, in __call__
    return self.wsgi_app(environ, start_response)
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1820, in wsgi_app
    response = self.make_response(self.handle_exception(e))
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1403, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1817, in wsgi_app
    response = self.full_dispatch_request()
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1477, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1381, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1475, in full_dispatch_request
    rv = self.dispatch_request()
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1461, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "/vagrant/wikimetrics/wikimetrics/controllers/cohorts.py", line 348, in delete_cohort
    delete_owner_cohort(session, cohort_id)
  File "/vagrant/wikimetrics/wikimetrics/controllers/cohorts.py", line 324, in delete_owner_cohort
    .filter(CohortStore.id == cohort_id) \
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/query.py", line 2670, in delete
    delete_op.exec_()
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/persistence.py", line 897, in exec_
    self._do_exec()
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/persistence.py", line 1023, in _do_exec
    params=self.query._params)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/session.py", line 991, in execute
    bind, close_with_result=True).execute(clause, params or {})
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 729, in execute
    return meth(self, multiparams, params)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/sql/elements.py", line 321, in _execute_on_connection
    return connection._execute_clauseelement(self, multiparams, params)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 826, in _execute_clauseelement
    compiled_sql, distilled_params
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 958, in _execute_context
    context)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1160, in _handle_dbapi_exception
    exc_info
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/util/compat.py", line 199, in raise_from_cause
    reraise(type(exception), exception, tb=exc_tb)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 951, in _execute_context
    context)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/default.py", line 436, in do_execute
    cursor.execute(statement, parameters)
  File "/usr/local/lib/python2.7/dist-packages/MySQLdb/cursors.py", line 205, in execute
    self.errorhandler(self, exc, value)
  File "/usr/local/lib/python2.7/dist-packages/MySQLdb/connections.py", line 36, in defaulterrorhandler
    raise errorclass, errorvalue
IntegrityError: (IntegrityError) (1451, 'Cannot delete or update a parent row: a foreign key constraint fails (`wikimetrics`.`cohort_tag`, CONSTRAINT `cohort_tag_ibfk_1` FOREIGN KEY (`cohort_id`) REFERENCES `cohort` (`id`))') 'DELETE FROM cohort WHERE cohort.id = %s' (21,)