dbus-python, pydbus, dbussy, or something else?

[Lawrence D'Oliveiro]

I wrote:

> One issue I haven’t fully tracked down yet is a reference circularity
> within the Ravel module, which means there is a build-up of orphaned
> message objects (up to a few dozen observed) until the garbage
> collector kicks in.

I believe I have finally fixed this. It happens with the definition of
an inner function that makes nonlocal references to locals of an outer
function, even if the inner function is never called or even referenced!

Replacing the nonlocal references with explicitly-passed function
arguments gets rid of the circularity.