Tribler does not start in Big Sur

[devos50]

Apple released macOS Big Sur yesterday. However, this seems to be incompatible with the Tribler 7.5.4 dmg. I can reproduce this issue. Starting Tribler gives the following output and then seems to do nothing anymore:

martijndevos@MacBook-Pro-van-Martijn MacOS % ./tribler
[PID:49492] 2020-11-13 10:26:41,750 - INFO - root(24) - __init__()
[PID:49492] 2020-11-13 10:26:41,850 - INFO - root(50) -   self._outSocket.error() = '2'
[PID:49492] 2020-11-13 10:26:41,850 - INFO - root(60) - __init__(): returning
[PID:49492] 2020-11-13 10:26:42,488 - INFO - TriblerGUI(134) - Will connect to events endpoint
[PID:49492] 2020-11-13 10:26:42,566 - INFO - TriblerGUI(78) - Got Tribler core error: 1

I suspect that the issue is related to PyQt, since the GUI is not showing up.

Is there anyone else with Big Sur that can test this?

[devos50]

Possibly related to pyinstaller/pyinstaller#5107

Edit: it seems that we are still using PyInstaller 3.6. We should try it with Pyinstaller 4 first.

Edit 2: upgrading to Pyinstaller 4 is not fixing the issue.

[drew2a]

Is there anyone else with Big Sur that can test this?

I can test it soon.

[devos50]

Unfortunately, I can reproduce this issue when bundling the following program with PyInstaller, and running it on Big Sur:

import sys
from PyQt5.QtWidgets import QApplication, QMainWindow

app = QApplication(sys.argv)
window = QMainWindow()
window.show()

app.exec_()

This means that the issue is likely somewhere in PyInstaller + PyQt5.

[devos50]

It actually seems to be a PyQt5 issue, based on this, this and this report. Riverbank will hopefully release a version of PyQt5 that works on Big Sur.

Downgrading PyQt5 to 5.13.1 is reported to resolve the problem. However, I'm not sure if Brew has a bottle for this version, meaning that we have to manually compile PyQt5...

[devos50]

Workaround that seems to fix the issue (thanks to this PyInstaller issue):

os.environ["QT_MAC_WANTS_LAYER"] = "1"

Tested it and it seems to correctly start Tribler 👍 . I will implement this workaround as soon as I can.