Tor complains that it can't find a ClientTransportPlugin line, when managed proxy dies.
In #5070 (moved), arma says that when he sets his torrc to:
ClientTransportPlugin obfs2 exec /path/to/nonexistent/file --managed
he gets this in his logs:
Feb 10 03:23:28.000 [warn] Could not launch managed proxy executable!
Feb 10 03:23:28.000 [warn] You have a Bridge line using the obfs2 pluggable transport, but there doesn't seem to be a corresponding ClientTransportPlugin line.
which is not true.