Sorry a diff between the two schema's, to make this a bit simpler, since I tend to think this is the fault, but i'm not sure why it was not upgraded and why it doesn't matter on 10.6.4 (i can think/guess, but i'm not a maria dev)

diff base_install.proc.sql backedup.proc.sql
5c5
< -- Server version 10.6.4-MariaDB-1:10.6.4+maria~focal
---
> -- Server version 10.6.4-MariaDB-1:10.6.4+maria~focal-log
26c26
<   `db` char(64) CHARACTER SET utf8mb3 COLLATE utf8mb3_bin NOT NULL DEFAULT '',
---
>   `db` char(64) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin NOT NULL DEFAULT '',
37c37
<   `definer` varchar(384) CHARACTER SET utf8mb3 COLLATE utf8mb3_bin NOT NULL DEFAULT '',
---
>   `definer` varchar(384) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin NOT NULL DEFAULT '',
41,44c41,44
<   `comment` text CHARACTER SET utf8mb3 COLLATE utf8mb3_bin NOT NULL,
<   `character_set_client` char(32) CHARACTER SET utf8mb3 COLLATE utf8mb3_bin DEFAULT NULL,
<   `collation_connection` char(32) CHARACTER SET utf8mb3 COLLATE utf8mb3_bin DEFAULT NULL,
<   `db_collation` char(32) CHARACTER SET utf8mb3 COLLATE utf8mb3_bin DEFAULT NULL,
---
>   `comment` text CHARACTER SET utf8mb4 COLLATE utf8mb4_bin NOT NULL,
>   `character_set_client` char(32) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin DEFAULT NULL,
>   `collation_connection` char(32) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin DEFAULT NULL,
>   `db_collation` char(32) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin DEFAULT NULL,
48c48
< ) ENGINE=Aria DEFAULT CHARSET=utf8mb3 PAGE_CHECKSUM=1 TRANSACTIONAL=1 COMMENT='Stored Procedures';
---
> ) ENGINE=Aria DEFAULT CHARSET=utf8mb4 PAGE_CHECKSUM=1 TRANSACTIONAL=1 COMMENT='Stored Procedures';
60c60
< -- Dump completed on 2021-09-30 21:10:49
---
> -- Dump completed on 2021-09-30 21:12:29

On Thu, Sep 30, 2021 at 5:55 PM Jeff Dyke <jeff.dyke@gmail.com> wrote:

Failing process:

Install mariadb from ppa using apt (happens through salt, fwiw)

Download last night's backup from a 10.6.4 server, which is a replica from a galera cluster.

run the script attached restore_mariabackup.sh

Once this is done the database itself works, for our application, but any client trying to access anything that requires mysql.proc gets an error similar to:

Sep 30 19:29:07 devmaria /etc/mysql/debian-start[24656]: error    : Corrupt
Sep 30 19:29:07 devmaria /etc/mysql/debian-start[24656]: sys.x$schema_table_statistics

Sep 30 19:29:07 devmaria /etc/mysql/debian-start[24656]: Error    : Cannot load from mysql.proc. The table is probably corrupted

I just built two new servers, one that builds mariadb and then overwrites the data from a backup and one that just installs mariadb.  The two different files base_install.proc.sql and backupedup.proc.sql.  The error output from sudo mysql_upgrade on the server that received the backup is in mysql_upgrade.out  

There are more differences in the proc table if i dump the data as well, but i think much of it is driven by the utf8_mb4 rather than 3. 

Tried to keep this sucient and use attachments.  This process has worked for me for until i upgraded to 10.6.4.  Please ask anything you need. I think i've been using this similar process to build dev machines since about 10.4

Thanks

Jeff