Comment 1 for bug 1206011

I ran into this issue when I was trying to run some tests using a new dbus for each test (i.e. so notifications don't interfere with the system ones).
I observed that the python dbus library cached the bus (i.e. session_bus), but when closing that explicitly it used the first DBUS_SESSION_BUS_ADDRESS that it had used which by the time of the 2nd test had be closed and non-existent.