Arch Linux

Cadeyrn

Member

Registered: 2013-04-06

Posts: 170

SMPlayer and VLC segfaulting after update

I just updated my system, and now SMPlayer immediately segfaults on launch. The package smplayer did not have an update, but some of its dependencies and optional dependencies did. I just tried downgrading all of those to the versions I had before, but it still segfaults. I'm at a loss.

EDIT: OK, VLC is also segfaulting. This is now a critical issue that needs to be fixed immediately. I'll see if restarting the computer solves it.

EDIT2: Restarting didn't fix it and it looks like *every* QT5 application is segfaulting and can't run.

EDIT3: Somehow, downgrading *only* the qt5 packages that upgraded today did not fix it. However, downgrading ALL of qt5 has fixed it. When I get the time, if no one else has by then, I will zero in on which package and which version exactly triggers this issue.

EDIT4: OK, actually, it only fixed SMPlayer and QJackCtl, and VLC now works in command line mode but still can't have a GUI. So whatever is wrong with QT5 right now, I had to downgrade packages that weren't even upgraded today just to *sort of* fix *some* of it.

Last edited by Cadeyrn (2020-07-10 21:07:18)

Lone_Wolf

Administrator

From: Netherlands, Europe

Registered: 2005-10-04

Posts: 15,391

Re: SMPlayer and VLC segfaulting after update

Do you get the error message shown in https://wiki.archlinux.org/index.php/Qt … Qt5_update ?

---

Disliking systemd intensely, but not satisfied with alternatives so focusing on taming systemd.

clean chroot building not flexible enough ?
Try clean chroot manager by graysky

Cadeyrn

Member

Registered: 2013-04-06

Posts: 170

Re: SMPlayer and VLC segfaulting after update

I have never seen that error. I decided to confirm whether it has anything to do with my using qt5ct to set gtk2 style, but it doesn't seem to. Here is VLC's output, the only output I've been able to get out of any QT program that is more than just a straight-up segfault:

$ env QT_QPA_PLATFORMTHEME= QT_STYLE_OVERRIDE= vlc
VLC media player 3.0.11 Vetinari (revision 3.0.11-0-gdc0c5ced72)
[000055f9ef8b25b0] main libvlc: Running vlc with the default interface. Use 'cvlc' to use vlc without interface.
[000055f9ef9b9310] skins2 interface error: cannot instantiate dialogs provider
[000055f9ef94fd20] main playlist: playlist is empty
[000055f9ef9b9310] [cli] lua interface: Listening on host "*console".
VLC media player 3.0.11 Vetinari
Command Line Interface initialized. Type `help' for help.
> 

This is how VLC behaves if I have 100% of QT5's packages downgraded to 5.14.2. All other QT programs in my system either work fine, or require >=5.15 to run and output errors saying as such. No segfalts whatsoever.

I haven't narrowed down which qt5-* packages need to be downgraded yet, but only downgrading the ones* that had upgraded in the upgrade that triggered this issue wasn't enough, which implies this is more likely down to a combination of packages and their versions rather than just one. Whichever of QT5's packages are causing the issue, if I have them on the newest version (currently 5.15.0-4 for qt5-base), then every single QT5 application in my system immediately segfaults with no other error messages at all.

I have not been able to get VLC's GUI back. In theory, *something* that got upgraded yesterday probably would restore that GUI on a downgrade, but since that something is not a qt5-* package, or any other dependency or even optional dependency of VLC, I have no leads to go on other than just rolling back my entire system.

*qt5ct, qt5-xmlpatterns, qt5-websockets, qt5-wayland, qt5-tools, qt5-script

Last edited by Cadeyrn (2020-07-11 15:28:24)

armandopk

Member

Registered: 2012-11-13

Posts: 19

Website

Re: SMPlayer and VLC segfaulting after update

I had the same problem, but, the solution were delete the config folder ".config/qt5ct/" after reboot,  all good. Good luck

barthel

Member

From: Saint Charles, MO

Registered: 2011-07-27

Posts: 25

Re: SMPlayer and VLC segfaulting after update

I also updated today and have been working around the issues which started when LXQt wouldn't launch.

I found this thread (moonlight-qt segfaults) which led me to the solution: qt5-styleplugins is no longer in the repository, but I was using the GTK theme provided by that package. (QT_QPA_PLATFORMTHEME=qt5ct)

The AUR package of qt5-styleplugins has the patches for Qt 5.15. (Don't use the git version from 2017.)

After building the AUR version, the Qt programs I tested were launching instead of segfaulting, so I'm about to log out and go back to LXQt. (I wanted to add this note while I still had the relevant links for copying.)

If everything is good, I will look at changing my defaults so I no longer need to depend on the AUR version.

Good luck!

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Any technology distinguishable from magic is insufficiently advanced.
    - Cleon, _Foundation's Fear_

Cadeyrn

Member

Registered: 2013-04-06

Posts: 170

Re: SMPlayer and VLC segfaulting after update

I'm confused. It looks like I already had the AUR version of qt5-styleplugins installed this whole time, not the git version, but its newest version number is still 5.0.0.20170311, as in 2017. Is there a newer version somewhere? The AUR version already has a patch for 5.15.

Last edited by Cadeyrn (2020-07-11 19:35:28)

Lone_Wolf

Administrator

From: Netherlands, Europe

Registered: 2005-10-04

Posts: 15,391

Re: SMPlayer and VLC segfaulting after update

Check the whole version number including pkgrel .
The latest version is 5.0.0.20170311-22 .

Looking at the upstream repo , https://github.com/qt/qtstyleplugins/commits/master , there is no later version from upstream then the 2017 - 03 - 11 commit .

Last edited by Lone_Wolf (2020-07-12 11:13:53)

---

Disliking systemd intensely, but not satisfied with alternatives so focusing on taming systemd.

clean chroot building not flexible enough ?
Try clean chroot manager by graysky

Cadeyrn

Member

Registered: 2013-04-06

Posts: 170

Re: SMPlayer and VLC segfaulting after update

OK, turns out just disabling qt5ct with environment variables wasn't enough. I'm back up to date and I have things working, because I did in fact have to delete ~/.config/qt5ct and start over. And I've even found the exact source of the segfault.

The kicker is it's GTK2 theming. So I can't have GTK2 theming anymore without a segfault, as of QT 5.15. This despite my having the newest version of qt5-styleplugins installed (5.0.0.20170311-22), with its GTK2 style plugin and 5.15 patch.

Is anyone else unable to use GTK2 theming in qt5ct without a segfault right now? Is this a widespread bug?

barthel

Member

From: Saint Charles, MO

Registered: 2011-07-27

Posts: 25

Re: SMPlayer and VLC segfaulting after update

I did a rebuild of the AUR package and was able to continue with the GTK theming option.

However, since I didn't want to run into this again, I did some digging and installed the Kvantum-QT5 package.

Yes, there's a bit of broken symmetry because Adwaita, but overall I'm satisfied with the Kvantum look.

Good luck!

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Any technology distinguishable from magic is insufficiently advanced.
    - Cleon, _Foundation's Fear_

Cadeyrn

Member

Registered: 2013-04-06

Posts: 170

Re: SMPlayer and VLC segfaulting after update

Unfortunately, rebuilding qt5-styleplugins does not fix it for me. I still segfault if it's set to gtk2. I'm also not a big fan of the Kvantum theme, and it looks like that package can only apply that specific theme to my entire system if I want a uniform look.

Is there anything else you've done that could have helped get it working, that maybe I haven't done yet?