How DISCARD the tablespace on mariadb while table is not found? I run the mysql_upgrade against my mariadb 10.3 and get the following error - see here for details.

ERROR 1813 (HY000) at line 85: Tablespace for table 'mysql.transaction_registry' exists. Please DISCARD the tablespace before IMPORT


When doing the DISCARD it does not work as the table does not exist

MariaDB [mysql]&gt; show tables;

+---------------------------+
| Tables_in_mysql           |
+---------------------------+
| column_stats              |
| columns_priv              |
| db                        |
| event                     |
| func                      |
| general_log               |
| gtid_slave_pos            |
| help_category             |
| help_keyword              |
| help_relation             |
| help_topic                |
| host                      |
| index_stats               |
| innodb_index_stats        |
| innodb_table_stats        |
| plugin                    |
| proc                      |
| procs_priv                |
| proxies_priv              |
| roles_mapping             |
| servers                   |
| slave_master_info         |
| slave_relay_log_info      |
| slave_worker_info         |
| slow_log                  |
| table_stats               |
| tables_priv               |
| time_zone                 |
| time_zone_leap_second     |
| time_zone_name            |
| time_zone_transition      |
| time_zone_transition_type |
| user                      |
+---------------------------+


MariaDB [mysql]&gt; ALTER TABLE transaction_registry DISCARD TABLESPACE;
ERROR 1146 (42S02): Table 'mysql.transaction_registry' doesn't exist


How to proceed in such a case?
After carefully checking again, I've found transaction_registry.ibd on the file system. So I manually deleted the file after stopping mariadb. Here you can see what I did:

sudo systemctl stop mariadb
sudo rm /var/lib/mysql/mysql/transaction_registry.ibd
sudo systemctl startb mariadb
sudo mysql_upgrade -u root --force -pxxxxx
...