#77 Krita crashes with qt5ct plugin with Qt5.15

[Vladimir Lomov]

Hello,
I'm using Archlinux x86_64, recently my distro updated Qt5 library (in 'testing' repository) and krita 4.2.9 crashes on start if I set QT_QPA_PLATFORMTHEME=qt5ct. Without this setting krita starts fine.

I attached backtrace from gdb and output from valgrind.

I searched a bit and found only some things about QPalette,
here: https://code.qt.io/cgit/qt/qtbase.git/tree/dist/changes-5.15.0/?h=v5.15.0 (search for palette)
here: https://doc-snapshots.qt.io/qt5-5.15/style-reference.html
and here: https://doc-snapshots.qt.io/qt5-5.15/qpalette.html

I'm not familiar with Qt and don't know if this is helpful information.

---

WBR, Vladimir Lomov

[Vladimir Lomov]

Hello,
to complete picture: this is my qt5ct configuration:

Style: Fusion
Standard dialogs: GTK3
Palette: custom
  Color scheme: darker
Fonts: Consolas
Icon theme: Faenza
Style Sheets: none (none selected)

[trialuser02]

Please, try latest SVN version.

[Antonio Rojas]

Same crash with svn rev569

[Vladimir Lomov]

I didn't try the svn version but I'm using qt5ct 0.41-4 package which has latest changes (actually only revision r564) and krita still segfaults.

[Vladimir Lomov]

Hello,
may be it related, may be not I'm not Qt5 programmer but to compile qt5-styleplugin package (now moved from Archlinux repository to AUR, https://aur.archlinux.org/packages/qt5-styleplugins/) one needs to apply a patch, this is the link to a patch
https://build.opensuse.org/package/view_file/KDE:Qt:5.15/libqt5-qtstyleplugins/fix-build-qt5.15.patch?expand=1

---

WBR, Vladimir Lomov

[trialuser02]

I'm unable to reproduce this issue with latest stable Arch. I'm using qt5ct 0.41-4 and plasma installed:
QT_QPA_PLATFORMTHEME=qt5ct krita

So, show me output with QT_DEBUG_PLUGINS=1 variable and attach qt5ct config (from ~/.config directory).

[Antonio Rojas]

I have patched the Arch krita package to workaround this issue. If you want to reproduce it, please use krita 4.2.9-4, which you can get from https://archive.archlinux.org/packages/k/krita/

[Vladimir Lomov]

Hello. I have updated krita (4.2.9-5) and it works (theme is applied). The 4.2.9-4 version (downloaded from archive.archlinux.org, thank you Antonio for the link!) crashes. Just to help you figure out what is going on I attached qt5ct.conf and krita run with QT_DEBUG_PLUGINS=1.

[trialuser02]

Reproduced, thank you. 4.2.9-4 crashes with same backtrace.

[alium]

i think, it's same bug: https://bugs.archlinux.org/task/66883

i tried qt5ct-svn rev 569, but still same error (SIGSEGV)

[trialuser02]

Please, test latest SVN version or this patch: [r570]

[alium]

for me r570 works and i see no problems anymore

[Vladimir Lomov]

Hello,
with qt5ct 0.41-5 and krita 4.2.9-6 the krita works flawlessly.

[alium]

qt5ct 0.41-5 contains patch r570, so it works

[Winston Weinert]

In case anybody was wondering, Vlad and alium were referring to the Archlinux package bump qt5ct-0.41-5 which contains the mentioned patch.

[trialuser02]

Fixed in 1.0 release. Thank you for testing.