On Wed, Dec 13, 2017 at 03:33:01PM +0000, Fernando Casas Schössow wrote:
> Maybe I’m missing something here but, if I recall correctly, the qemu process for the guest is terminated when this problem happens. So how a debugger will be attached to a process that is gone?

Sorry, this got lost in my inbox.

assert(false) sends SIGABRT to the process.  The default behavior is to
dump a core file that can be analyzed later with GDB.

Your system must have core dumps enabled (i.e. ulimit -c unlimited).
Also, various pieces of software like systemd's coredumpctl can
influence where and how core dumps are stored.

But in short, an assertion failure produces a core dump.

Stefan