Try with no su

src/freedombone-image-customise

 		if [ ${#CONFIG_FILENAME} -gt 2 ]; then
 			cp $CONFIG_FILENAME $rootdir/root/$PROJECT_NAME.cfg
 			cat $rootdir/root/$PROJECT_NAME.cfg
-			chroot "$rootdir" su -c "$PROJECT_NAME -c /root/$PROJECT_NAME.cfg" - root
+			chroot "$rootdir" $PROJECT_NAME -c /root/$PROJECT_NAME.cfg
 		fi
 	fi
 }