Run dbus-uuidgen on system startup (again).

src/scripts/customize_rootfs.sh

Index: src/scripts/customize_rootfs.sh
diff --git a/src/scripts/customize_rootfs.sh b/src/scripts/customize_rootfs.sh
index 5f165b75f23d74dd43169b7c146e942d98a72614..4a0a8580ff6293b97d886fc8c38a304fdbe61548 100755
--- a/src/scripts/customize_rootfs.sh
+++ b/src/scripts/customize_rootfs.sh
@@ -238,6 +238,10 @@ sudo ln -s /var/cache "${ROOT_FS_DIR}/var/lib/xkb"
 sudo rm -rf "${ROOT_FS_DIR}/var/lib/DeviceKit-disks"
 sudo ln -s /var/tmp "${ROOT_FS_DIR}/var/lib/DeviceKit-disks"
 
+# dbus-uuidgen writes machine-id to /var/lib/dbus.
+sudo rm -f "${ROOT_FS_DIR}/var/lib/dbus/machine-id"
+sudo ln -s /var/cache/machine-id "${ROOT_FS_DIR}/var/lib/dbus/machine-id"
+
 # Remove pam-mount's default entry in common-auth and common-session
 sudo sed -i 's/^\(.*pam_mount.so.*\)/#\1/g' "${ROOT_FS_DIR}"/etc/pam.d/common-*