calibre 5.44 Linux 64-bit, "E-book viewer" stuck on "Loading book..."

[NotAMobofCrows]

Trying to open the included "Quick Start Guide" ePub, so should be no problems on that end. Noticed a number of "QtWebEngineProcess" tasks running when E-book viewer was stuck. However, no packages with "qtwebengine" in their name were installed. I then installed:

geoclue-2.0 (2.5.6-0ubuntu1~18.04.sav0)
iio-sensor-proxy (2.4-2)
libavcodec57 (7:3.4.11-0ubuntu0.1)
libavformat57 (7:3.4.11-0ubuntu0.1)
libavutil55 (7:3.4.11-0ubuntu0.1)
libevent-2.1-6 (2.1.8-stable-4build1)
libminizip1 (1.1-8build1)
libqt5positioning5 (5.9.5+dfsg-0ubuntu2)
libqt5qml5 (5.9.5-0ubuntu1.1)
libqt5quick5 (5.9.5-0ubuntu1.1)
libqt5quickwidgets5 (5.9.5-0ubuntu1.1)
libqt5webchannel5 (5.9.5-0ubuntu1)
libqt5webengine-data (5.9.5+dfsg-0ubuntu2)
libqt5webengine5 (5.9.5+dfsg-0ubuntu2)
libqt5webenginecore5 (5.9.5+dfsg-0ubuntu2)
libqt5webenginewidgets5 (5.9.5+dfsg-0ubuntu2)
libre2-4 (20180201+dfsg-2)
libswresample2 (7:3.4.11-0ubuntu0.1)
libvpx5 (1.7.0-3ubuntu0.18.04.1)
libx264-152 (2:0.152.2854+gite9a5903-2)
libx265-146 (2.6-3)
python3-pyqt5.qtwebchannel (5.10.1+dfsg-1ubuntu2)
python3-pyqt5.qtwebengine (5.10.1+dfsg-1ubuntu2)

By installing

python3-pyqt5.qtwebengine

and the rest were installed as dependencies. Still no change. Do I need these packages? Are there other packages I should be installing? Or is it something else? Thanks.

Kernel: 5.4.0-122-generic #138~18.04.1-Ubuntu SMP Fri Jun 24 14:14:03 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux

[kovidgoyal]

calibre bundles all its dependencies. It's something else on your system. POssibly GPU drivers, you can try disabling hardware acceleration as described in https://doc.qt.io/qt-5/qtwebengine-debugging.html

[NotAMobofCrows]

Thanks, but either I'm reading the instructions wrong, or it doesn't work. I did remove the packages listed above:

calibre --remote-debugging-port=55 --disable-gpu
Usage: calibre [options] [path_to_ebook or calibre url ...]

Launch the main calibre Graphical User Interface and optionally add the e-book at
path_to_ebook to the database. You can also specify calibre URLs to perform various
different actions, than just adding books. For example:

calibre://view-book/test_library/1842/epub

Will open the book with id 1842 in the EPUB format from the library
"test_library" in the calibre E-book viewer. Library names are the folder names of the
libraries with spaces replaced by underscores. A full description of the
various URL based actions is in the User Manual.


Whenever you pass arguments to calibre that have spaces in them, enclose the arguments in quotation marks. For example: "/some path/with spaces"

calibre: error: no such option: --remote-debugging-port

Thanks.

[kovidgoyal]

you need those settings in the environment variable,

[aardbewoner]

Chicken me i use fbreader on raspberrypi 4 headless, but great work Kovid the arm version chapeau.

[NotAMobofCrows]

Originally Posted by kovidgoyal

you need those settings in the environment variable,

How may I do this?

[kovidgoyal]

QTWEBENGINE_CHROMIUM_FLAGS="whatever" calibre

[NotAMobofCrows]

No change running:

QTWEBENGINE_CHROMIUM_FLAGS="--disable-gpu" calibre

[kovidgoyal]

then you are out of luck. Qt Webengine isnt compatible with your system.

[NotAMobofCrows]

What was the last version of Calibre to not use the Qt Webengine? Version 3.21 works fine, but hoping there's a more recent one I can use. Thanks.

[NotAMobofCrows]

Version 3.48. Is odd though, because 5.44 was working fine until some updates of some sort.

[JSWolf]

Originally Posted by NotAMobofCrows

Version 3.48. Is odd though, because 5.44 was working fine until some updates of some sort.

Linux is very good for updates to the OS breaking things.

[sc0ttwad3]

Possibly related (but this is Windows 10/11 Calibre Portable x64, Qt6 version 6.3.1)...

Once I upgraded to the 6.x version of Calibre, the epub Viewer gets stuck at varying places. Both 6.0 and 6.1 do this. It's not specific to any epubs (I've tried known working, and new/first opens). The viewer FREEZES at any time while viewing or trying to open: at the "Loading book, please wait," or while reading the book changing the page, or even just going to highlight a sentence and suddenly nothing is responsive but the Exit button to close the application. For the same epub, it FREEZES in different points (on open, page change, highlight, etc.) each time you open it, so there is no specific "spot" the viewer is hitting.

I've uninstalled reinstalled, same problem. I'm thinking this is related, but if not, I'll create a new thread.

[sc0ttwad3]

NOTE: Version 5.x of the viewer opens the same epubs without ever FREEZING.

[kovidgoyal]

It will be GPU driver issues. Try updating your GPU drivers or disabling hardware rendering as described at https://doc.qt.io/qt-6/qtwebengine-debugging.html