Crash in mariadb-backup --prepare --export after --prepare

diff --git a/mysql-test/suite/mariabackup/partial.test b/mysql-test/suite/mariabackup/partial.test

index d0d07daf2ea..035024aac3d 100644

--- a/mysql-test/suite/mariabackup/partial.test

+++ b/mysql-test/suite/mariabackup/partial.test

@@ -41,6 +41,7 @@ EOF

 echo # xtrabackup prepare;

 --disable_result_log

+exec $XTRABACKUP --defaults-file=$server_cnf --defaults-group-suffix=.1 --prepare --target-dir=$targetdir;

 exec $XTRABACKUP --defaults-file=$server_cnf --defaults-group-suffix=.1 --prepare --export --target-dir=$targetdir;

 --enable_result_log

mariabackup: /mariadb/10.5/storage/innobase/fil/fil0fil.cc:441: bool fil_node_open_file(fil_node_t*): Assertion `fil_is_user_tablespace_id(node->space->id) || srv_operation == SRV_OPERATION_BACKUP || srv_operation == SRV_OPERATION_RESTORE || srv_operation == SRV_OPERATION_RESTORE_DELTA' failed.

mariabackup: /mariadb/10.6/storage/innobase/fil/fil0fil.cc:426: bool fil_node_open_file(fil_node_t*): Assertion `fil_is_user_tablespace_id(node->space->id) || srv_operation == SRV_OPERATION_BACKUP || srv_operation == SRV_OPERATION_RESTORE || srv_operation == SRV_OPERATION_RESTORE_DELTA' failed.