pkconfig: export full search path as .pc variable

src/path-lookup.c

@@ -181,6 +181,8 @@ int lookup_paths_init(LookupPaths *p, ManagerRunningAs running_as) {
                                 return -ENOMEM;
                 } else
                         if (!(p->unit_path = strv_new(
+                                              /* If you modify this you also want to modify
+                                               * systemdsystemunitpath= in systemd.pc.in! */
                                               "/dev/.systemd/system",
                                               SYSTEM_CONFIG_UNIT_PATH,
                                               "/etc/systemd/system",

systemd.pc.in

@@ -11,6 +11,7 @@ systemdsystemunitdir=@systemunitdir@
 systemduserunitdir=@pkgdatadir@/user
 systemdsystemconfdir=@pkgsysconfdir@/system
 systemduserconfdir=@pkgsysconfdir@/user
+systemdsystemunitpath=/dev/.systemd/system:${systemdsystemconfdir}:/etc/systemd/system:/usr/local/share/systemd/system:/usr/share/systemd/system:/lib/systemd/system:${systemdsystemunitdir}
 
 Name: systemd
 Description: systemd System and Service Manager