Qt 6: Segfaults on macOS with QT_DEBUG_PLUGINS

[The-Compiler]

• ./.venv/bin/python -c 'from PyQt6.QtWidgets import QApplication; QApplication([])': works
• QT_DEBUG_PLUGINS=1 ./.venv/bin/python -c 'from PyQt6.QtWidgets import QApplication; QApplication([])': segfaults

Stack:

Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0   QtCore                        	0x0000000108ddd088 0x108bfa000 + 1978504
1   QtCore                        	0x0000000108dd9649 AppleUnifiedLogger::cachedLog(QString const&, QString const&) + 153
2   QtCore                        	0x0000000108dd9349 AppleUnifiedLogger::messageHandler(QtMsgType, QMessageLogContext const&, QString const&, QString const&) + 201
3   QtCore                        	0x0000000108c09ab0 0x108bfa000 + 64176
4   QtCore                        	0x0000000108c09868 0x108bfa000 + 63592
5   QtCore                        	0x0000000108c0975d qt_message_output(QtMsgType, QMessageLogContext const&, QString const&) + 13
6   QtCore                        	0x0000000108c10897 QDebug::~QDebug() + 103
7   QtCore                        	0x0000000108ed6785 0x108bfa000 + 3000197
8   QtCore                        	0x0000000108ed964b 0x108bfa000 + 3012171
9   QtCore                        	0x0000000108ed5879 0x108bfa000 + 2996345
10  libsystem_c.dylib             	0x00007fff604043cf __cxa_finalize_ranges + 319
11  libsystem_c.dylib             	0x00007fff604046b3 exit + 55
12  libdyld.dylib                 	0x00007fff6035e3dc start + 8

originally reported by @donaldguy in #7202 (comment).

[The-Compiler]

We should report this to Qt (or PyQt?) and also for now probably disable that variable in mkvenv.py (or implement a rerun when it fails, or just ignore that particular segfault somehow...)

[The-Compiler]

Seems to be a 6.3 regression? 6.2 looks better...

[The-Compiler]

[QTBUG-104415] [REG 6.3] Segfault on exit in AppleUnifiedLogger::messageHandler with QT_DEBUG_PLUGINS - Qt Bug Tracker

[The-Compiler]

Fixed in qt6-v2.