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hgr · 12-28-2022, 03:01 PM

Yep, another one of these - after using 4.23 for a long time to manage my paltry library under (up-to-date) Opensuse Leap 15.4 I decided to switch to 6.10 - and guess what, when trying my epubs (more or less all of them) the viewer froze. Reverting back to 4.23 restored usability, but this was not quite satisfying.
So I got curious and tested the whole thing on my Mint 21.1 (also up-to-date) notebook and there everything worked like a charm with 6.10.
The first thing I found when investigating were a lot of references to Python and this looked a bit suspicious, because there was this switch to Python3 with Calibre 5 - and guess what again, the same symptom with the frozen viewer resurfaced after installation of Calibre 5 on the Leap box (and went away after reverting to 4.23). But Python3 is present properly on both machines, and I also checked the xdb libraries.
The last advice checked was Govid's hint to set the Qt environment variable off for acceleration (set QTWEBENGINE_CHROMIUM_FLAGS="--disable-gpu"; export QTWEBENGINE_CHROMIUM_FLAGS). This seems to solve the problem for the Leap 15.4 installation - maybe because this is a Nouveau setup?
Yes, the original problem is solved, I will continue my tests and research, anybody got an explanation about this Bermuda triangle of GPU, Python and Qt?

12-28-2022, 03:01 PM	#1
hgr Junior Member Posts: 2 Karma: 10 Join Date: Nov 2013 Device: Sony PRS T2	Viewer frozen when opening EPUB Yep, another one of these - after using 4.23 for a long time to manage my paltry library under (up-to-date) Opensuse Leap 15.4 I decided to switch to 6.10 - and guess what, when trying my epubs (more or less all of them) the viewer froze. Reverting back to 4.23 restored usability, but this was not quite satisfying. So I got curious and tested the whole thing on my Mint 21.1 (also up-to-date) notebook and there everything worked like a charm with 6.10. The first thing I found when investigating were a lot of references to Python and this looked a bit suspicious, because there was this switch to Python3 with Calibre 5 - and guess what again, the same symptom with the frozen viewer resurfaced after installation of Calibre 5 on the Leap box (and went away after reverting to 4.23). But Python3 is present properly on both machines, and I also checked the xdb libraries. The last advice checked was Govid's hint to set the Qt environment variable off for acceleration (set QTWEBENGINE_CHROMIUM_FLAGS="--disable-gpu"; export QTWEBENGINE_CHROMIUM_FLAGS). This seems to solve the problem for the Leap 15.4 installation - maybe because this is a Nouveau setup? Yes, the original problem is solved, I will continue my tests and research, anybody got an explanation about this Bermuda triangle of GPU, Python and Qt?