[erlang-questions] gdb questions (was Segfault in do_allocate_logger_message)

[Vince Foley]

I think you are right here.. I've been experimenting with running gdb with
the exact beam file from the dump and getting better results. This is my
first time using gdb for anything :)

Do you know of any documentation around building "unstripped" erlang
releases? This is my next step...

I'm going to post a new analysis soon.


On Tue, Apr 24, 2018 at 12:33 AM, Roger Lipscombe <roger@REDACTED>
wrote:

> On 21 April 2018 at 21:51, Vince Foley <vincefoley@REDACTED> wrote:
> > Side question.. I am trying to use the etp commands to print out the
> Erlang
> > terms
> > (https://github.com/erlang/otp/blob/master/erts/etc/unix/etp-commands.in
> )
> >
> > I keep getting this error:
> > ```
> > (gdb) etp *bp
> > Cannot access memory at address 0xb974e0
> > ```
> >
> > And this kind of thing:
> > ```
> > (gdb) etp-processes
> > No processes, since system isn't initialized!
> > ```
> >
> > Am I doing something wrong, or is this just not possible with my
> coredump?
>
> I've found that success with gdb requires:
>
> - An exactly matching beam. I have to keep an appropriate VM around
> for debugging core dumps from production.
> - An *unstripped* beam loaded into gdb. Deb packages generally have
> stripped binaries, which breaks a bunch of debugging scenarios. We
> build our Erlang releases with kerl; we have to keep the unstripped
> copies around.
>
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