Subject: Re: bug#34138: 27.0.50; Delayed display of PDF file images

From: Eli Zaretskii <[email-masked]>
Date: Sun, 20 Jan 2019 18:50:00 +0200

> From: Stephen Berman <[email-masked]>
> Cc: [email-masked],  [email-masked],  [email-masked],  [email-masked]
> Date: Sun, 20 Jan 2019 17:31:13 +0100
> 
> > Hmm... can you attach the debugger to Emacs during that delay, and
> > show both C backtrace and Lisp backtrace?
> 
> I'm not sure what "attach the debugger to Emacs during that delay"
> means

It means, during the time of the delay, type from the shell prompt:

  $ gdb -p PID

where PID is the numeric process-id of the Emacs process; you should
find that in advance, e.g. by running "ps".  Once GDB starts and shows
its prompt, "(gdb)", type:

  (gdb) thread apply all bt

This should show the C-level backtrace.  Then:

  (gdb) source /path/to/emacs/src/.gdbinit
  (gdb) xbacktrace

The last command should show the Lisp-level backtrace.

Thanks.