Tracebacks in plugins 'viewrendered3' & 'freewin' on Fedora 41

Viktor Ransmayr

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Apr 23, 2025, 12:15:28 PMApr 23

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Hello Edward & Thomas,

I recently switched a set of VMs from Fedora Linux 40 to 41.

This also resulted in a complete new installation of Leo 6.8.3 from PyPI.

After the new installation some of them reported tracebacks - See "Log-001".

On all of them I had the plugins 'viewrendered3' & 'freewin' enabled.

I was able to resolve the issue by switching to the 'viewrendered' plugin & to disable the 'freewin' plugin. - See "Log-002".

I assume it has to do with either the newer Python - and / or - the newer Qt version ...

Shall I create a bug-report for this issue ?

With kind regards,

Viktor

### Log-001

Leo Log Window
Leo 6.8.3, master branch
Python 3.13.2, PyQt version 6.9.0
linux
setting leoID from os.getenv('USER'): 'user'
home: /home/user
leo-editor: /home/user/PyVE/PyPI/Leo/lib64/python3.13/site-packages
load: /home/user/PyVE/PyPI/Leo/lib64/python3.13/site-packages/leo/core
config: /home/user/PyVE/PyPI/Leo/lib64/python3.13/site-packages/leo/config
reading settings in /home/user/PyVE/PyPI/Leo/lib64/python3.13/site-packages/leo/config/leoSettings.leo
reading settings in /home/user/.leo/myLeoSettings.leo
reading settings in /home/user/PyVE/PyPI/Leo/lib64/python3.13/site-packages/leo/themes/tbp_dark_solarized.leo
Traceback (most recent call last):
File "/home/user/PyVE/PyPI/Leo/lib64/python3.13/site-packages/leo/core/leoPlugins.py", line 545, in loadOnePluginHelper
__import__(moduleName)
~~~~~~~~~~^^^^^^^^^^^^
File "/home/user/PyVE/PyPI/Leo/lib64/python3.13/site-packages/leo/plugins/viewrendered3.py", line 1043, in <module>
qwv = QtWebEngineWidgets.QWebEngineView
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'QWebEngineView'
Traceback (most recent call last):
File "/home/user/PyVE/PyPI/Leo/lib64/python3.13/site-packages/leo/core/leoPlugins.py", line 545, in loadOnePluginHelper
__import__(moduleName)
~~~~~~~~~~^^^^^^^^^^^^
File "/home/user/PyVE/PyPI/Leo/lib64/python3.13/site-packages/leo/plugins/freewin.py", line 294, in <module>
QWebEngineView = QtWebEngineWidgets.QWebEngineView
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'QWebEngineView'
reading settings in /home/user/Documents/SL2025.leo
Traceback (most recent call last):
File "/home/user/PyVE/PyPI/Leo/lib64/python3.13/site-packages/leo/core/leoPlugins.py", line 545, in loadOnePluginHelper
__import__(moduleName)
~~~~~~~~~~^^^^^^^^^^^^
File "/home/user/PyVE/PyPI/Leo/lib64/python3.13/site-packages/leo/plugins/viewrendered3.py", line 1043, in <module>
qwv = QtWebEngineWidgets.QWebEngineView
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'QWebEngineView'
Traceback (most recent call last):
File "/home/user/PyVE/PyPI/Leo/lib64/python3.13/site-packages/leo/core/leoPlugins.py", line 545, in loadOnePluginHelper
__import__(moduleName)
~~~~~~~~~~^^^^^^^^^^^^
File "/home/user/PyVE/PyPI/Leo/lib64/python3.13/site-packages/leo/plugins/freewin.py", line 294, in <module>
QWebEngineView = QtWebEngineWidgets.QWebEngineView
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'QWebEngineView'
read outline in 0.02 seconds

### Log-002

Leo Log Window
Leo 6.8.3, master branch
Python 3.13.2, PyQt version 6.9.0
linux
setting leoID from os.getenv('USER'): 'user'
home: /home/user
leo-editor: /home/user/PyVE/PyPI/Leo/lib64/python3.13/site-packages
load: /home/user/PyVE/PyPI/Leo/lib64/python3.13/site-packages/leo/core
config: /home/user/PyVE/PyPI/Leo/lib64/python3.13/site-packages/leo/config
reading settings in /home/user/PyVE/PyPI/Leo/lib64/python3.13/site-packages/leo/config/leoSettings.leo
reading settings in /home/user/.leo/myLeoSettings.leo
reading settings in /home/user/PyVE/PyPI/Leo/lib64/python3.13/site-packages/leo/themes/tbp_dark_solarized.leo
reading settings in /home/user/Documents/SL2025.leo
read outline in 0.02 seconds

Thomas Passin

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Apr 23, 2025, 1:16:06 PMApr 23

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This sounds like the same problem we just closed an issue for (https://github.com/leo-editor/leo-editor/issues/4327). It's a problem with the 6.9.0 QtWebEngine not playing well with the graphics card. Try exporting this setting:

QTWEBENGINE_CHROMIUM_FLAGS=--disable-gpu

If that doesn't fix the problem, then you will have to use an earlier version of the WebEngine until Trolltech releases a newer version without the bug.

Thomas Passin

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Apr 23, 2025, 1:55:29 PMApr 23

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It's also possible that you have a version mismatch between PyQt6 and PyQt6-WebEngine-Qt6. Here are the versions I have in an EndeavorOS VM and both vr3 and Freewin run correctly on it:

(leo) [tom@thomas-virtualbox ~]$ python3 -m pip list |grep -i qt
PyQt6 6.9.0
PyQt6-QScintilla 2.14.1
PyQt6-Qt6 6.9.0
PyQt6_sip 13.9.1
PyQt6-WebEngine 6.9.0
PyQt6-WebEngine-Qt6 6.9.0
sphinxcontrib-qthelp 2.0.0

But when PyQt was at 6.8.something and the WebEngine was at 6.9.0, I got a similar failure.

Viktor Ransmayr

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Apr 23, 2025, 2:52:19 PMApr 23

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Hello Thomas,

tbp1...@gmail.com schrieb am Mittwoch, 23. April 2025 um 19:16:06 UTC+2:

This sounds like the same problem we just closed an issue for (https://github.com/leo-editor/leo-editor/issues/4327). It's a problem with the 6.9.0 QtWebEngine not playing well with the graphics card. Try exporting this setting:

QTWEBENGINE_CHROMIUM_FLAGS=--disable-gpu

This suggestion does not work in my Fedora 41 VM. - See log below ...

With kind regards,

Viktor

###

(Leo) [user@fedora-leo-study-vm Leo]$
(Leo) [user@fedora-leo-study-vm Leo]$ export QTWEBENGINE_CHROMIUM_FLAGS=--disable-gpu
(Leo) [user@fedora-leo-study-vm Leo]$
(Leo) [user@fedora-leo-study-vm Leo]$ env | grep 'QTWEB'
QTWEBENGINE_CHROMIUM_FLAGS=--disable-gpu
(Leo) [user@fedora-leo-study-vm Leo]$
(Leo) [user@fedora-leo-study-vm Leo]$ leo &
[1] 1838
(Leo) [user@fedora-leo-study-vm Leo]$ setting leoID from os.getenv('USER'): 'user'

Leo 6.8.3, master branch
Python 3.13.2, PyQt version 6.9.0
linux

Viktor Ransmayr

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Apr 23, 2025, 2:55:15 PMApr 23

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Hello Thomas,

tbp1...@gmail.com schrieb am Mittwoch, 23. April 2025 um 19:55:29 UTC+2:

It's also possible that you have a version mismatch between PyQt6 and PyQt6-WebEngine-Qt6. Here are the versions I have in an EndeavorOS VM and both vr3 and Freewin run correctly on it:

(leo) [tom@thomas-virtualbox ~]$ python3 -m pip list |grep -i qt
PyQt6 6.9.0
PyQt6-QScintilla 2.14.1
PyQt6-Qt6 6.9.0
PyQt6_sip 13.9.1
PyQt6-WebEngine 6.9.0
PyQt6-WebEngine-Qt6 6.9.0
sphinxcontrib-qthelp 2.0.0

But when PyQt was at 6.8.something and the WebEngine was at 6.9.0, I got a similar failure.

No version mismatch. - My setup looks very similar:

(Leo) [user@fedora-leo-study-vm Leo]$ python -m pip list | grep -i qt

PyQt6 6.9.0
PyQt6-QScintilla 2.14.1
PyQt6-Qt6 6.9.0

PyQt6_sip 13.10.0

PyQt6-WebEngine 6.9.0
PyQt6-WebEngine-Qt6 6.9.0
sphinxcontrib-qthelp 2.0.0

(Leo) [user@fedora-leo-study-vm Leo]$

With kind regards,

Viktor

Thomas Passin

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Apr 23, 2025, 3:00:35 PMApr 23

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I forgot that with a Virtualbox VM, you get software rendering as far as I know. This could make a difference.

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