I've built PyQt5 5.10.1 against Qt 5.5 with the --qml-debug flag.
When I import QtQml I get the message "QML debugging is enabled. Only use this in a safe environment."
but whenever I try to run my application, passing arguments to the QApplication constructor, there's no indication that running my app with the -qmljsdebugger=port:1234,block option does anything. I'm expecting a message like "QML Debugger: Waiting for connection on port 1234", or "QML Debugger: Ignoring "qmljsdebugger=port:1234". Debugging has not been enabled.", but neither of these messages are displayed.
I've tried printing QApplication.arguments(), and the qmljsdebugger argument is not there, but the name of the program is.
I've tried passing ['program.py', '-qmljsdebugger=port:1234,block'] directly to the QApplication() constructor, but the second argument is not visible from the call to QApplication.arguments(). Funny enough if i remove the leading '-' from the argument, it shows up in that list but doesn't do anything.
debugging was not being turned on because i was using QQmlEngine instead of QQmlApplicationEngine.
PyQt5 QML Debugging enabled, qmljsdebugger option doesn't do anything