I have a bit of a chicken and an egg problem. In a test program I want to start a local dbus-daemon so the test program can run in isolation, but I end up doing this too late because the NVIDIA driver has already initialized the dbus library before I get to the point where I can easily start my own dbus-daemon and set DBUS_SESSION_BUS_ADDRESS in the environment. I can work around this, but it is going to be a little cumbersome, so I was hoping there was a way, e.g via an environment variable, to instruct the NVIDIA driver not to use dbus.