Re: The emacs_backtrace "feature"

[Christoph Scholtes]

On 9/22/2012 6:05 AM, Richard Stallman wrote:
>      Core dumps are better than backtraces if they're available, but
>      modern GNUish distributions often disable them, alas, and they're
>      a pain to send via email, and it's nice to have a bit more info
>      than 'Fatal error 27' when Emacs crashes.
>
> If you get a core dump, you can run GDB and make a backtrace
> and mail that.

If you get a core dump, you _have_ to run GDB and make a backtrace. Some 
users might not know how nor care to know how to generate a backtrace 
from a core dump. I believe this is independent of the platform they are 
running on.

I think an automated way of generating backtraces is a good idea. The 
more we can automate the process of gathering information in case of a 
crash, the more likely users are to submit that information.

What do you think about the following:

Check if gdb is available (on startup, or when the crash happens).
If it is, run something like 'gdb -batch-silent -ex 'thread apply all bt 
full'' and save backtrace to a file that can be attached to bug report.
If it isn't, fall back to the backtrace() function and generate at least 
something.

Or we ask the user what she wants to do:

1. Create backtrace (with or without gdb) and attach to bug report
2. Attach debugger
3. Nothing

This could be an option, too, like debug-on-error: 
create-backtrace-on-error or something like that.

Christoph