PyQt5-5.15.3 problem: "ImportError: Failed to import any qt binding"

[ullix]

Am 02.03.21 um 09:57 schrieb Phil Thompson:
> On 02/03/2021 08:46, ullix wrote:
>> Same result on Py3.6, Py3.7, Py3.8, Py3.9, running in a venv:
>>
>> all works fine when using PyQt5-5.15.2, but after upgrading to
>> PyQt5-5.15.3 it fails.
>>
>> The traceback message is:
>>
>> ...
>>   File "/home/ullix/geigerlog/geigerlog/gsup_utils.py", line 69, in 
>> <module>
>>     import matplotlib.backends.backend_qt5agg
>>   File
>> "/home/ullix/geigerlog/vgl39/lib/python3.9/site-packages/matplotlib/backends/backend_qt5agg.py", 
>>
>> line 11, in <module>
>>     from .backend_qt5 import (
>>   File
>> "/home/ullix/geigerlog/vgl39/lib/python3.9/site-packages/matplotlib/backends/backend_qt5.py", 
>>
>> line 16, in <module>
>>     import matplotlib.backends.qt_editor.figureoptions as figureoptions
>>   File
>> "/home/ullix/geigerlog/vgl39/lib/python3.9/site-packages/matplotlib/backends/qt_editor/figureoptions.py", 
>>
>> line 11, in <module>
>>     from matplotlib.backends.qt_compat import QtGui
>>   File
>> "/home/ullix/geigerlog/vgl39/lib/python3.9/site-packages/matplotlib/backends/qt_compat.py", 
>>
>> line 177, in <module>
>>     raise ImportError("Failed to import any qt binding")
>> ImportError: Failed to import any qt binding
>>
>>
>> Does 5.15.3 have a known bug?
>>
>> What does the error even mean, do I need to program differently?
>>
>> Going back to 5.15.2 makes everything fine again.
>>
>> ullix
>
> Have you read this...
>
> https://www.riverbankcomputing.com/pipermail/pyqt/2021-February/043644.html 
>
>
> Phil


Thanks.

Well, using Py3.9 the plain uninstall/ install cycle with either only 
PyQt5, only PyQt5-sip, or both by:

      python3 -m pip uninstall pyqt5-sip pyqt5

did NOT work, and resulted in the same error


However, the force-reinstall, worked, though it claimed to already have 
that installation:

$ python3 -m pip install --force-reinstall PyQt5-Qt
Collecting PyQt5-Qt
   Using cached PyQt5_Qt-5.15.2-py3-none-manylinux2014_x86_64.whl (59.9 MB)
Installing collected packages: PyQt5-Qt
   Attempting uninstall: PyQt5-Qt
     Found existing installation: PyQt5-Qt 5.15.2
     Uninstalling PyQt5-Qt-5.15.2:
       Successfully uninstalled PyQt5-Qt-5.15.2
Successfully installed PyQt5-Qt-5.15.2

Pip now finds these packages:

    PyQt5            5.15.3
    PyQt5-Qt         5.15.2
    PyQt5-sip        12.8.1

Is a fix on the way? It is getting cumbersome to explain to the users of 
my software what all extra steps to take. :-(

ullix