Behaviour changes:
+• As a result of the move from Autotools to Meson as the recommended
+ build system on Unix, the names of all build-time options have changed.
+ Not all Meson options are a 1:1 replacement for their closest equivalent
+ in Autotools, so the options used for a dbus build should be reviewed.
+
+• If `meson install` is run as root, and traditional (non-systemd)
+ activation is enabled, the ownership and setuid permission of
+ dbus-daemon-launch-helper are not set automatically.
+ This is not the same as the historical behaviour of the Autotools build
+ system, which would set the ownership and permissions automatically if
+ run as uid 0.
+ The ownership and permissions must now be set by OS distribution packaging,
+ or as a manual post-installation step if dbus is installed directly
+ without going via a packaging system (which is not recommended).
+
• On Unix, the well-known system bus socket is in the runtime state
directory by default (normally /run)
(see 1.15.4 for more details)