[Pkg-kde-extras] Bug#1042376: digikam crashes with "Illegal instruction"

[Detlef Matthiessen]

On 19.08.23 22:00, Steven Robbins wrote:
> 1. Test a build without SSE4.

   I built 8.1.0-2 from sources (which took 70 minutes on my machine,
btw), removed the version from "sid" that I had installed the other day
and then did:
root at fluke:~# dpkg -i digikam_8.1.0-2_amd64.deb
digikam-data_8.1.0-2_all.deb digikam-private-libs_8.1.0-2_amd64.deb

   Lo and behold! It works flawlessly and is even able to show videos
(something that the 8.2.0 AppImage from KDE, that I had been using in
the meantime
(https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1042376#25), failed at).

> 2. Dig further with the debugger to understand what the illegal instruction
> is.  I may be completely wrong in assuming it is an SSE4 instruction --
> particularly given the fact that the test code we discussed August 13/14
> builds the same with/without the -msse4.1 flag.  If you are handy with gdb you
> can probably dig into the assembly and figure out what the instruction is.

   Now that I'm in the possession of working packages for digikam, I
could volunteer to assist you in finding out the root cause of the crash
(which I assume probably affects only a small number of users anyway).
However, it has been literally decades that I've done any serious
programming in C/C++. Any hints on how to use gdb in this regard and
what to look for would be highly appreciated.

   Kind regards,

     Detlef