"Bj�rn Lundin" wrote in message news:mailman.65.1105991123.527.comp.lang.ada@ada-france.org... Hello all! A couple of weeks I sent the mail below, but got no answers. Well, I then tried to use gnat 3.4.2 from minGW, instead of 3.15.p, but I got he same results still. Besides, it it only me that misses libaddr2line, used to print stacktraces? It was included in 3.15p, but now I cant find it :( Looks to me like this function returns a thread specific value so it should be ok. Clearly it is not ok for some reason. I'd guess something about the exception propagation within the threaded run-time support is clearing that error value. I see no reason why it should I recommend you submit a bugzilla bug at the gcc site. At the very least this should be documented.