https://issues.dlang.org/show_bug.cgi?id=10364
--- Comment #8 from Jacob Carlborg <d...@me.com> --- (In reply to Vladimir Panteleev from comment #7) > I reproduced it with macOS 10.12 and DMD 2.074. > > Changing daemon(0,0) to daemon(0,1) (so that stderr isn't redirected to > /dev/null) reveals a clue: > > core.thread.ThreadError@src/core/thread.d(3002): Unable to load thread state > > It looks like the daemon() call is interfering with Druntime's threading > code. I did some more debugging. The error returned by "thread_get_state" is 268435459 (0x10000003) which seems to correspond to MACH_SEND_INVALID_DEST. This bug had the same error code [1] [1] https://issues.dlang.org/show_bug.cgi?id=6135 --