Created attachment 45577 [details]
Here's a tiny Python program demonstrating the issue

I'm experimenting with turning off introspection on a bunch of objects in the Telepathy-Gabble test suite (to speed it up).

Of course, this means that we'd have to specify explicit signatures in a bunch of places. While looking at how hard it would be to do this for some of the simpler interfaces, I noticed that you can't specify signature='' when making blocking method calls. Confusingly, the exception thrown is:

  TypeError: call_blocking() got multiple values for keyword argument 'signature'

even though I only specified signature='' once.

On the IRC, Simon says: “you'll have to use Connection.call_async (or call_blocking)”. I could also use dbus.Variant() and friends around all the arguments. But I feel like this should work.