Arch Linux with Qt5 getting "the PyQt5.QtCore and PyQt4.QtCore modules both wrap the QObject class"

[Mohd Lee]

I'm running FlatCAM using python2.7 on up to date Arch Linux x64 and have all the necessary library and package installed. I keep getting the PyQt5.QtCore and PyQt4.QtCore modules both wrap the QObject class until I added 2 lines in PlotCanvas.py

from PyQt4 import QtGui, QtCore
import matplotlib #new line
matplotlib.use("Qt4Agg") #new line

Not sure if this applies to other distro.

[Juan Pablo Caram]

If you are getting an error, please post it here. Is FlatCAM not starting?

[Mohd Lee]

Sorry, did I post it at the wrong place? Yes, it won't start, throwing the exception, but I managed to fix it by add the 2 lines of code. Though not sure if that's applicable for other distro.

[Juan Pablo Caram]

This is the right place. Please post the exact error.

I think this is starting to become a problem because of the other packages adopting Qt5. Your fix is probably the correct thing to do. Will need to test it on other distributions/versions.

[Mohd Lee]

python2.7 FlatCAM.py

Traceback (most recent call last):
  File "FlatCAM.py", line 3, in <module>
    from FlatCAMApp import App
  File "/home/faulty/build/flatcam/FlatCAMApp.py", line 20, in <module>
    from PlotCanvas import *
  File "/home/faulty/build/flatcam/PlotCanvas.py", line 11, in <module>
    from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as FigureCanvas
  File "/usr/lib/python2.7/site-packages/matplotlib/backends/backend_qt4agg.py", line 17, in <module>
    from .backend_qt5agg import NavigationToolbar2QTAgg
  File "/usr/lib/python2.7/site-packages/matplotlib/backends/backend_qt5agg.py", line 18, in <module>
    from .backend_qt5 import QtCore
  File "/usr/lib/python2.7/site-packages/matplotlib/backends/backend_qt5.py", line 27, in <module>
    import matplotlib.backends.qt_editor.figureoptions as figureoptions
  File "/usr/lib/python2.7/site-packages/matplotlib/backends/qt_editor/figureoptions.py", line 17, in <module>
    import matplotlib.backends.qt_editor.formlayout as formlayout
  File "/usr/lib/python2.7/site-packages/matplotlib/backends/qt_editor/formlayout.py", line 58, in <module>
    from matplotlib.backends.qt_compat import QtGui, QtWidgets, QtCore
  File "/usr/lib/python2.7/site-packages/matplotlib/backends/qt_compat.py", line 111, in <module>
    from PyQt5 import QtCore, QtGui, QtWidgets
RuntimeError: the PyQt5.QtCore and PyQt4.QtCore modules both wrap the QObject class

[Juan Pablo Caram]

I've added the fix in the latest commit. Could you please test it?