With Dave Barnes' help, we have determined that Xcode 8.3 is the problem. If you have already upgraded to Xcode 8.3, you can rollback to Xcode 8.2.1 to restore functionality.
Sarge > On 29 Mar, 2017, at 15:25, Michael William Dodge <mdo...@pivotal.io> wrote: > > With the recent upgrade to macOS 10.12.4 and Xcode 8.3, we're seeing a > SIGSEGV/EXC_BAD_ACCESS with pthread_mutex_lock() which is part of the > initialization of the ACE libraries. I haven't done enough debugging to know > whether it's caused by an incompatibility between ACE and the 10.12.4 > runtimes (e.g., a struct has changed in size) or if it's an actual bug in the > runtimes. Mike Martell found a bug that has already been filed about Emacs > crashing with pthread-related problems after this update, so our current > theory is that there's a problem in the pthreads library from Apple. > > Sarge
