OBS-Studio No Longer Launches since QT Update

General system Applications
1

I updated QT yesterday and since then I am unable to launch OBS-Studio. I get the following error message:

Warning: QT_DEVICE_PIXEL_RATIO is deprecated. Instead use:
   QT_AUTO_SCREEN_SCALE_FACTOR to enable platform plugin controlled per-screen factors.
   QT_SCREEN_SCALE_FACTORS to set per-screen DPI.
   QT_SCALE_FACTOR to set the application global scale factor.
Cannot mix incompatible Qt library (5.15.0) with this library (5.15.1)
[1]    5834 abort (core dumped)  obs

I reported a bug with the arch package and my bug report was closed with the following message:

I just checked. I have the following QT packages instaled: qt5-base, qt5-declarative, qt5-svg, qt5-wayland, qt5-x11extras. All of them are on 5.15.1-1. obs-studio is 25.0.8-2. Is working without problem.

It seems like obs is expecting the previous version of the QT library and not the current one.

2

Just checked (not much help I admit), but it is working here. Do you have the git version or the repo version?

If you have the git version you will need to rebuild.

3

I use the version from the community repo.

4

Do you have mlocate installed?

Try:

locate qt  | grep -i  "5.15.0"

This returns nothing on my install, but “5.15.1” returns everything as expected.

You haven’t held a package in pacman.conf?
image

Or use find:

find /usr/lib -name "*5.15.0*"
5

It’s an unintended partial upgrade - one of your Qt packages hasn’t been upgraded. Check again for updates, and e.g. make sure your mirror is up-to-date.

5 Likes
6

Which is put more succinctly than me! Just woken up.

3 Likes
7

I get those 2:

/usr/lib/python3.8/site-packages/PyQtWebEngine-5.15.0.dist-info
/usr/lib/python3.8/site-packages/PyQt5-5.15.0.dist-info
8

I did update the mirrors and I still have no additional updates.

9

Have you rebooted since your update? Is it possible you have some old libraries resident somewhere?

10

Yes, I have rebooted. Where should I be looking for old libraries?

11

I haven’t used this, but since this big QT debacle and lots of people having issues with the upgrade, this has been recommended for downgrading; downgrader-git in AUR.

1 Like
12

Version from official repository (non git) running here without any problems either (25.0.8-2). What Desktopenvironment are you using?

13 
loc pyqtweb
/usr/lib/python3.8/site-packages/PyQtWebEngine-5.12.1.dist-info
/usr/lib/python3.8/site-packages/PyQtWebEngine-5.12.1.dist-info/INSTALLER
/usr/lib/python3.8/site-packages/PyQtWebEngine-5.12.1.dist-info/METADATA
/usr/lib/python3.8/site-packages/PyQtWebEngine-5.12.1.dist-info/RECORD
/usr/lib/python3.8/site-packages/PyQtWebEngine-5.12.1.dist-info/WHEEL

1 extra/python-pyqtwebengine 5.15.0-2 (118.9 KiB 619.6 KiB) [pyqt5] (Installed)
    Python bindings for QtWebEngine

loc is an alias. Something is not up to date. You appear to be in a partial upgrade situation.

So:

sudo reflector --verbose --latest 40 --sort rate --save /etc/pacman.d/mirrorlist
sudo pacman -Syyu

Should fix it.

1 Like
14

I did this and the only update I got was a steam update. The library conflict reamains.

15

I am using XFCE.

16 
sudo pacman -S qt5

Will reinstall the lot, worth a try.

17

The number of Qt packages needed by obs-studio is pretty limited:

$ pactree obs-studio | grep qt
├─qt5-svg
│ └─qt5-base
├─qt5-x11extras
│ └─qt5-base

So, if each of these are up-to-date then it’s something else, e.g. qt5ct.

1 Like
18

I am getting that error with multiple other qt applications such as qpdfview and onionshare. I tried rebuilding the qt packages and the python qt packages that were outdated have now been updated.

   QT_AUTO_SCREEN_SCALE_FACTOR to enable platform plugin controlled per-screen factors.
   QT_SCREEN_SCALE_FACTORS to set per-screen DPI.
   QT_SCALE_FACTOR to set the application global scale factor.
Cannot mix incompatible Qt library (5.15.0) with this library (5.15.1)
[1]    6552 abort (core dumped)  qpdfview
19

Someone posted a fix in the Arch Forums last night and it actually worked for me too which is reinstalling qt5-styleplugins . Marking as solution, thank you for helping troubleshoot this.

20

Which is an AUR package presumably built agains qt 5.15.0, hence the message …

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