I got help from Lucas to get access to a machine where the problem is exposed, and have tried to debug a bit further. This was a hard problem to figure out because nodejs hijack the signal pinpointing the exact crash location, and I have not yet understood exactly what go wrong. But I am a bit further.
The crash happen in DetachAsync() called from the "create, attach, detach player" step. As far as I can tell, the crash is in the line r->errcode = groove_player_detach(r->player); This was determined by sprinkling printf-like statements around the code. I've been unable to figure out where the groove_player_detach() call is, and have run out of time for today. Perhaps this information can help someone else get further? Note, the warning from helgrind is a red herring, and is showing up independent of the segfault. -- Happy hacking Petter Reinholdtsen