Assertion connection_state_is_connecting(conn) failed

From the blog comments:

ftw newer see it before:
Nov 25 01:25:48.000 [err] tor_assertion_failed_(): Bug: src/or/connection.c:3680: connection_handle_event_cb: Assertion connection_state_is_connecting(conn) failed; aborting.
Nov 25 01:25:48.000 [err] Bug: Assertion connection_state_is_connecting(conn) failed in connection_handle_event_cb at src/or/connection.c:3680. (Stack trace not available)

(https://blog.torproject.org/blog/tor-0275-released-and-stable#comment-137420)

Not sure if that is related to #4697 (moved) but that's the only reference trac gave me after a quick search.