Debian 12 and Lyx 2.3.7-1

[Folsk Pratima]

On Tue, 31 Oct 2023 09:31:13 +0000
Peter<peter.northerly at gmail.com> wrote:

> Hi, I have just upgraded to Debian 12 and find Lyx will not load.  In
> addition, trying to load it seems to crash xorg, so the only way out
> is to reboot.  I was going to post the slew of error messages from
> the terminal, but as soon as I opened Claws the display became
> unusable.  Moving the cursor led to a broad black line across the
> display, and clicking no longer worked.
> 
> I have tried starting Lyx from the terminal as a different user, and
> I get this:
> 
> [different user]:~$ lyx
> qt.qpa.xcb: could not connect to display 
> qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even
> though it was found. This application failed to start because no Qt
> platform plugin could be initialized. Reinstalling the application may
> fix this problem.
> 
> Available platform plugins are: eglfs, linuxfb, minimal, minimalegl,
> offscreen, vnc, wayland-egl, wayland, wayland-xcomposite-egl,
> wayland-xcomposite-glx, xcb.
> 
> I have checked, and xcb is installed.
> 
> Any suggestions?  Should I try to revert to an earlier version, which
> worked just fine under Debian 11, and if so how would one do that?  I
> have tried reinstalling as suggested above, but it makes no
> difference.
> 
> What happens on launch is that a large window with no borders comes
> up.  The Lyx starting logo is in the middle.  But there is no
> toolbar, neither right nor left clicks work either.
> 
> This is Debian 12 with fluxbox. 
> 
> Any help gratefully received.  I can try running debug if anyone
> knows what flags to use and what to look for.
> 
> Peter

I did not upgrade from Debian 11, but made a clean install and Lyx
works just fine, so it is problem with your upgrade. AFAIK it is common
for X to break on Debian upgrade.

Sorry, I am not going to be much help but if you are really
desperate you could try doing something nuclear like
```
dpkg-query -f '${Package} ${db:Status-Status}\n' -W '*xorg*' -W '*gtk*'
-W '*qt*' | awk '/ installed$/'
```
and deleting all (or most) of the packages. It will be a bit of a hassle
to install them all again especially if your installation is big, but it
*might* fix you problem.

Also, a tiny bit of lurking:
https://stackoverflow.com/questions/67272188/debian-10-qt-qpa-plugin-could-not-load-the-qt-platform-plugin-xcb-in-eve
I assume it's not likely "$DISPLAY" is missing, but maybe really some
xcb libraries got deleted during upgrade? Are other qt applications
working?

You can also `apt purge lyx` and then install in again...

You can also `strace lyx > ~/tmp/trace 2>&1` and then skim trough it
after reboot, but believe me that's not going to be pretty.