Wednesday, December 25, 2019

I had an AttributeError: 'TableHandle' object has no attribute 'store' traceback on an Lino Amici production site. It went away after reload_services_sh. So it was maybe the same reason as #3178. The problem with that ticket is that we cannot reproduce it.

This time the traceback helped me to understand a bug in lino.core.actors.Actor._get_handle():

def _get_handle(self, ar, hname):
    h = self.__dict__.get(hname, None)
    if h is None:
        h = self._handle_class(self)
        setattr(self, hname, h)
        settings.SITE.kernel.setup_handle(h, ar)
    return h

What happens when an exception occurs during setup_handle()? This method should not store the handle instance in that case. Because the exception is caught by calling code, so the unfinished handle remains in memory and gets used by subsequent calls, causing tracebacks like the above one. Now the setattr() is being called after setup_handle(). I have some hope that this might fix ticket #3178.

En passant I removed the methods because AFAICS it isn’t used anywhere any more.