Use /var/run/dbus/system_bus_socket for the D-Bus socket

man/systemd-bus-proxyd@.service.xml

@@ -59,7 +59,7 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>.
     <para><filename>systemd-bus-proxyd.socket</filename> will launch
     <filename>systemd-bus-proxyd@.service</filename> for connections
     to the classic D-Bus socket in
-    <filename>/run/dbus/system_bus_socket</filename>.</para>
+    <filename>/var/run/dbus/system_bus_socket</filename>.</para>
 
     <para><filename>systemd-bus-proxyd@.service</filename> is launched
     for an existing D-Bus connection and will use

src/libsystemd/sd-bus/PORTING-DBUS1

@@ -536,7 +536,7 @@ parameter.
 Client libraries should use the following connection string when
 connecting to the system bus:
 
-   kernel:path=/dev/kdbus/0-system/bus;unix:path=/run/dbus/system_bus_socket
+   kernel:path=/dev/kdbus/0-system/bus;unix:path=/var/run/dbus/system_bus_socket
 
 This will ensure that kdbus is preferred over the legacy AF_UNIX
 socket, but compatibility is kept. For the user bus use:

src/shared/def.h

@@ -61,7 +61,7 @@
         "/usr/lib/kbd/keymaps/\0"
 #endif
 
-#define UNIX_SYSTEM_BUS_PATH "unix:path=/run/dbus/system_bus_socket"
+#define UNIX_SYSTEM_BUS_PATH "unix:path=/var/run/dbus/system_bus_socket"
 #define KERNEL_SYSTEM_BUS_PATH "kernel:path=/dev/kdbus/0-system/bus"
 
 #ifdef ENABLE_KDBUS

units/systemd-bus-proxyd.socket

@@ -9,5 +9,5 @@
 Description=Legacy D-Bus Protocol Compatibility Socket
 
 [Socket]
-ListenStream=/run/dbus/system_bus_socket
+ListenStream=/var/run/dbus/system_bus_socket
 Accept=yes