In pyqt5, in tree_widget.py the following code worked without any kind of wrapping:

def save_sort(column, qt_sort_order):
    storage = weakStorage()
    if storage:
        storage.put(self.storage_key, [column, qt_sort_order])

self.tree_view.header().sortIndicatorChanged.connect(save_sort)

In pyqt6, the enum Qt::SortOrder managed by the sortIndicatorChanged signal is now a python Enum, which JSON seems unable to process.

TypeError: Object of type SortOrder is not JSON serializable

Handle this issue via the JSONEncoder.

Click on the column header in the coins tab, and check that sorting now works and is persisted accross restarts.

Do this for pyqt5 and pyqt6

QT_API=pyqt6 ~/dev/bitcoin-abc/electrum/electrum-abc'