enter key bug?

[jack]

in linux, at the prompt "Press any key to continue" if I press the enter key, I get

[xcb] Unknown request in queue while dequeuing
[xcb] Most likely this is a multi-threaded client and XInitThreads has not been called
[xcb] Aborting, sorry about that.
mpfr_test1: ../../src/xcb_io.c:165: dequeue_pending_request: Assertion `!xcb_xlib_unknown_req_in_deq' failed.
Aborted (core dumped)

looks like bug to me