Thanks.  Unfortunately, the standard recipe for making core dumps on Mac (put "limit core unlimited" into /etc/launchd.conf and reboot, make sure /cores is writable, set ulimit -c unlimited) seem to actually enable them on MacOS Catalina (10.15.2).  I have tested with SIGQUIT and SIGSEGV on running processes and no dumps appear in /cores.

On Tue, Jan 21, 2020 at 4:02 AM Ludovic Courtès <> wrote:

John Cowan <> skribis:

> Yes, gladly, but I don't know how to get one in this context.

You would unpack, configure, and build like you did before (with JIT
enabled, so as to reproduce the crash), but before that you’d run
“ulimit -c unlimited” in that shell to make sure there’s a core dumped
when it crashes.

Once it has crashed, locate the ‘core’ file (or ‘core.*’), and run, say:

  gdb libguile/.libs/guile bootstrap/core

Then from the GDB prompt:

  thread apply all bt