How to debug dbus access issues?

[Simon McVittie]

On Tue, 23 Aug 2011 at 12:43:12 +0200, tomw wrote:
> Python and SessionBus   - works

The session bus has a default-allow security policy, because it isn't a
security boundary (all applications in the login session are assumed to be
equally-privileged).

> Python and SystemBus    - does not work:

The system bus has a default-deny security policy. Put a .conf file in
/etc/dbus-1/system.d that allows what you want to allow; as an example that is
simple enough to understand, but not *too* simple, I usually recommend looking
at the policy for Avahi.

The format of the access control policy configuration language is defined in
the dbus-daemon man page.

    S