[erlang-bugs] Twisty turny gen_server hang

[Matthew Dempsky]

Here's a simpler test case:

    -module(bloop2).
    -compile(export_all).

    start() ->
        gen_server:start(?MODULE, [], []).

    init([]) ->
        exit(self(), burlap).

The cause seems to be that proc_lib:sync_wait/2 expects to receive an
EXIT message if Pid exits, but proc_lib:start* is often called from
contexts where the trap_exit flag is unset (e.g., gen_server).