D-Bus has evolved over the years. New features have been added with new D-Bus versions. There are two variables, which allow to determine the used D-Bus version.
This variable, a string, determines the version of D-Bus Emacs is
compiled against. If it cannot be determined the value is
The other D-Bus version to be checked is the version of D-Bus Emacs
runs with. This string can be different from
It is also
nil, if it cannot be determined at runtime.