Qt for Python (PySide/Shiboken)

Is there any way to find out where QQmlExpression: Attempted to evaluate an expression in an invalid context is happening? I see people puts breakpoints in C++ code to print stack traces but is something like this possible in PySide environment? Maybe some env variable to pass to enable debug mode? Also I can access QMessageLogContext by installing custom message handler (qInstallMessageHandler) but it looks like all debug information is missing for release builds…