git-cola@4.1.0: fails to launch

[odysseus9672 (Sean Lake)]

I have MacPorts version 2.8.1 installed, and git-cola 4.1.0. When I try to launch git-cola I get the following message:

git-cola

You do not seem to have PyQt (or PySide) and qtpy installed.
Please install the PyQt (or PySide) and qtpy into your Python environment.

For example, on a Debian/Ubuntu system you can install these using apt:

    sudo apt install python3-pyqt5 python3-pyqt5.qtwebkit python3-qtpy

When I examine /opt/local/bin/git-cola I see that it uses python3.11. Here is what I see when I look for qt related packages on my system:

port installed | grep -i qt
  gstreamer1-gst-plugins-good @1.16.2_5+gtk3+pulseaudio+qt+x11 (active)
  mkvtoolnix @77.0_0+qtgui (active)
  py38-pyqt5 @5.15.9_0 (active)
  py38-pyqt5-sip @12.12.1_0 (active)
  py38-qtpy @2.3.1_0 (active)
  py38-sphinxcontrib-qthelp @1.0.3_0 (active)
  py311-pyqt5 @5.15.9_0 (active)
  py311-pyqt5-sip @12.12.1_0 (active)
  py311-qtpy @2.3.1_0 (active)
  qt5 @5.15.10_0 (active)
  qt5-qt3d @5.15.10_0 (active)
  qt5-qtbase @5.15.10_0+openssl (active)
  qt5-qtconnectivity @5.15.10_0 (active)
  qt5-qtdeclarative @5.15.10_0 (active)
  qt5-qtgamepad @5.15.10_0 (active)
  qt5-qtgraphicaleffects @5.15.10_0 (active)
  qt5-qtimageformats @5.15.10_0 (active)
  qt5-qtlocation @5.15.10_0 (active)
  qt5-qtmacextras @5.15.10_0 (active)
  qt5-qtmultimedia @5.15.10_0 (active)
  qt5-qtnetworkauth @5.15.10_0 (active)
  qt5-qtquickcontrols @5.15.10_0 (active)
  qt5-qtquickcontrols2 @5.15.10_0 (active)
  qt5-qtremoteobjects @5.15.10_0 (active)
  qt5-qtscript @5.15.10_0 (active)
  qt5-qtscxml @5.15.10_0 (active)
  qt5-qtsensors @5.15.10_0 (active)
  qt5-qtserialbus @5.15.10_0 (active)
  qt5-qtserialport @5.15.10_0 (active)
  qt5-qtspeech @5.15.10_0 (active)
  qt5-qtsvg @5.15.10_0 (active)
  qt5-qttools @5.15.10_0 (active)
  qt5-qttranslations @5.15.10_0 (active)
  qt5-qtwebchannel @5.15.10_0 (active)
  qt5-qtwebsockets @5.15.10_0 (active)
  qt5-qtxmlpatterns @5.15.10_0 (active)
  qt5-sqlite-plugin @5.15.10_0 (active)
  qt6-qtbase @6.4.3_1+openssl (active)
  qt6-qtdeclarative @6.4.3_0 (active)
  qt6-qtimageformats @6.4.3_0 (active)
  qt6-qtlanguageserver @6.4.3_0 (active)
  qt6-qtshadertools @6.4.3_0 (active)
  qt6-qtsvg @6.4.3_0 (active)
  qt6-qttools @6.4.3_0 (active)
  qt6-qttranslations @6.4.3_0 (active)

As you can see, both py311-pyqt5 and py311-qtpy are installed.

I've tried looking for text files containing fragments of the error string git-cola is printing, but I cannot find them, so I don't know where the error is occurring. I, therefore, also cannot comment on whether this is a bug in git-cola's library version checking code, or if it's invoking some other python version that doesn't have the needed libs, making this a missing dependency bug.

[reneeotten (Renee Otten)]

sorry for the trouble... I did update the port to its current version earlier in the year and verified that it worked. Just installed it again now and I don't see any issues. It seems to me that the Python ports you have installed (py311-pyqt5 and py311-qtpy) should indeed suffice.

The only thing I can think of is that you perhaps have the QT_API environment variable set? That is what is used by QtPy to figure out what backend to use (if not set, it will use Qt5); so if you have it set to something else than PyQt5 the failure is likely because you don't have these Python bindings installed.

>>> port notes py311-qtpy
--->  py311-qtpy has the following notes:
  QtPy needs one of the following backends to be installed on your system: PyQt5, PyQt6,
  PySide2, or PySide6. If multiple backends are available, PyQt5 will be used unless you
  set the QT_API environment variable.

[odysseus9672 (Sean Lake)]

I don't have QT_API set.

Seans-Work-Macbook-Pro:~ sean$ echo $QT_API

Seans-Work-Macbook-Pro:~ sean$ git-cola

You do not seem to have PyQt (or PySide) and qtpy installed.
Please install the PyQt (or PySide) and qtpy into your Python environment.

For example, on a Debian/Ubuntu system you can install these using apt:

    sudo apt install python3-pyqt5 python3-pyqt5.qtwebkit python3-qtpy

I tried to install qt5-qtwebkit, thinking that might help, but it didn't.

If you can tell me where in the source code to find where this error message comes from, I can do a better job of nailing down exactly what's going wrong.

[ryandesign (Ryan Carsten Schmidt)]

Try running these commands... do you get an error?

python3.11
from PyQt5 import QtGui
from qtpy import QtGui

Then you can press Control-D to exit the python interpreter.

[reneeotten (Renee Otten)]

Replying to odysseus9672:

If you can tell me where in the source code to find where this error message comes from, I can do a better job of nailing down exactly what's going wrong.

You can just grep the source and find where it is: /opt/local/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/cola/app.py

[reneeotten (Renee Otten)]

also, looking again now we already patch the files such that the environment variable is set to Qt5. So in short, I am not sure this should work for you as well...

[odysseus9672 (Sean Lake)]

Looks like your suggestion has found the problem. When doing the imports suggested I get:

Seans-Work-Macbook-Pro:~ sean$ python3.11
Python 3.11.4 (main, Jun 10 2023, 10:30:46) [Clang 14.0.3 (clang-1403.0.22.14.1)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> from PyQt5 import QtGui
>>> from qtpy import QtGui
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/qtpy/__init__.py", line 57, in <module>
    from packaging.version import parse
ModuleNotFoundError: No module named 'packaging'
>>> 

I installed py311-packaging, and the imports now work, and git-cola now launches. So, qtpy is missing a dependency. I don't know if this affects all of the versions of qtpy, but someone should probably check.

[reneeotten (Renee Otten)]

In c6990b02abac9c7b49b6049360edf93c1651dbc3/macports-ports (master):

py-qtpy: add missing dependency

Closes: #67694