Help diagnosing gcc7 on MacOS 10.13 and SIGABRT

[David]

The interesting thing is that the same code, compiled with the same
compiler (gcc-mp-7 7.2) works just fine on 10.10. This doesn't happen on
every throw, just one in particular.

While not a bug (necessarily) I'm looking for some guidance on where to
look to track down the differences in the throw operation between the two
OS releases. Any assistance would be useful.

The following code is the specific location where the SIGABRT comes from.
We have pushed an exception into our stream and when we detect it we
reformat the payload and throw it for a higher layer to capture and
report. The contents of the payload matches the class Exception. Exception
contains only POD members.

  if ( m_packet->io.cmd_code == CmdAbort )
    throw *(Exception*)m_packet->io.payload;

The code throws exceptions in multiple other locations, and those all work
as expected.

Again, any hints would be very useful.

	David