Update on shared memory coarrays

[Thomas Koenig]

Hi Dominique,

> Indeed! I can try to do some debugging under supervision.
> Could you please tell me where to start?

Thanks for your offer.

The first thing to do would be to see where it hangs.  Generating
a syscall trace (by whatever tool is used on MacOS, dtrace? ktrace?)
would be a first step.

A next step would be to compile a program with debug info and
run it under a debugger, then see where it hangs.

I'm not sure - do you use gdb on your system?  If you do,
the following lines in your .gdbinit

define better_mp_debug
   set detach-on-fork off
   set schedule-multiple on
   set follow-fork-mode parent
   set non-stop on
   set target-async on
   set print symbol-loading off
end

will give you a macro "better_mp_debug" which will ease debugging
of forked processes enormously.

My lack of experience with MacOS extends to which tools to use
for debugging, unfortunately.

Best regards

	Thomas