Calibre crashing

[KevinH]

Yes, it appears from the back trace to be a bug in Qt's Accessibility code of some sort:

Thread 0 Crashed:: CoverWorker Dispatch queue: com.apple.main-thread
0 libobjc.A.dylib 0x191be9820 objc_msgSend + 32
1 QtGui 0x10d2729b8 QAccessibleCache::removeAccessibleElement(unsigned int) + 144
2 QtGui 0x10d6a2754 QAccessibleCache::deleteInterface(unsigned int, QObject*) + 3704
3 QtWidgets 0x104c24d70 0x104924000 + 3149168
4 QtGui 0x10d69b34c QAccessible::updateAccessibility(QAccessibleEvent* ) + 156
5 QtWidgets 0x104c2f074 QAbstractItemView::setRootIndex(QModelIndex const&) + 168
6 QtWidgets 0x104c6d9c8 QListView::setRootIndex(QModelIndex const&) + 84
7 PyQt6.QtWidgets.so 0x1054d7908 sipQListView::setRootIndex(QModelIndex const&) + 136
8 QtWidgets 0x104c2ed80 QAbstractItemView::reset() + 972
9 PyQt6.QtWidgets.so 0x1054d7870 sipQListView::reset() + 120
10 QtCore 0x101fd881c 0x101ea4000 + 1263644
11 QtCore 0x1021cb5b8 QAbstractItemModel::endResetModel() + 776
12 PyQt6.QtCore.so 0x102688be8 meth_QAbstractItemModel_endResetModel(_object*, _object*) + 104
13 Python 0x1017f9db0 cfunction_call + 96
14 Python 0x1018e27d4 _PyEval_EvalFrameDefault + 174964

But I thought all of these macOS Accessibility Issues were tracked down and fixed *before* Qt 6.8.2.

What version of Qt does this version of Calibre use?

[KevinH]

A quick search of the QtBug database reveals the following *potential* cause:

https://bugreports.qt.io/browse/QTBUG-134610

I do not know the calibre codebase well enough to know if multiple signals are being temporarily disconnected from an object or not. But this is one of the only still open issues associated with the QAccessibleCache in QtBugs.

There seems to be a Qt patch for Qt 6.8.4 that detects multiple signal disconnections that removes the "destroyed" signal that the QAccessibleCache code needs to stay in sync, and to warn people not to do that.

Of course, it could just be a new Qt bug as well.

[kovidgoyal]

calibre doesn't do disconnect all. Indeed it generally does disconnect by calling disconnect() on the python signal object not QObject. This disconnects all receivers of the specific signal only, and it never touches destroyed. And it uses Qt 6.8.2.

[KevinH]

So a new Accessibility related bug then.

[kovidgoyal]

Originally Posted by KevinH

So a new Accessibility related bug then.

In my experience accesibility has caused crashes in Qt on macOS going back decades. The calibre FAQ on macOS crashes calls out accessibility specifically.
https://manual.calibre-ebook.com/faq...shing-on-macos