I'm no longer talking about Cygwin (which builds fine without JIT).  I'm now talking about MacOS Catalina, which needs a core dump to debug, but on which nobody seems to know how to enable core dumps.

On Tue, Jan 21, 2020 at 1:41 PM szgyg <szgyg@ludens.elte.hu> wrote:
On Tue, Jan 21, 2020 at 10:01:58AM +0100, Ludovic Courtès wrote:
> but before that you’d run
> “ulimit -c unlimited” in that shell to make sure there’s a core dumped
> when it crashes.

This won't work on cygwin. If you want a core dump, you should use the
dumper tool, as described here
Or you can set error_start to gdb to get an interactive gdb session on error.