mysql (mariadb) won't start after power outage (MacOS) /var/log/system.log says (over and over)
Oct 13 19:34:01 Data-Server com.apple.xpc.launchd[1] (com.mariadb.server[2128]): Service exited with abnormal code: 1
Oct 13 19:34:01 Data-Server com.apple.xpc.launchd[1] (com.mariadb.server): Service only ran for 0 seconds. Pushing respawn out by 10 seconds.

/usr/local/var/mysql/Data-Server.local.err says (once recently, repeated a number of times well before the crash)
2020-10-13  2:44:25 20019181 [Warning] Aborted connection 20019181 to db: 'EcoReality' user: 'root' host: '10.1.2.2' (Got timeout reading communication packets)

First thing I did was to shutdown the launchctl entry, to keep it from constantly restarting.
# launchctl unload /Library/LaunchDaemons/com.mariadb.server.plist
Then I tried invoking mysqld manually:
# sudo  /usr/local/bin/mysqld -u mysql
2020-10-13 20:46:09 0 [Note] /usr/local/bin/mysqld (mysqld 10.4.6-MariaDB) starting as process 2364 ...
2020-10-13 20:46:09 0 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2020-10-13 20:46:09 0 [Note] InnoDB: Uses event mutexes
2020-10-13 20:46:09 0 [Note] InnoDB: Compressed tables use zlib 1.2.11
2020-10-13 20:46:09 0 [Note] InnoDB: Number of pools: 1
2020-10-13 20:46:09 0 [Note] InnoDB: Using SSE2 crc32 instructions
2020-10-13 20:46:09 0 [Note] InnoDB: Initializing buffer pool, total size = 128M, instances = 1, chunk size = 128M
2020-10-13 20:46:09 0 [Note] InnoDB: Completed initialization of buffer pool
2020-10-13 20:46:09 0 [ERROR] InnoDB: Invalid log block checksum. block: 81635496 checkpoint no: 2609153 expected: 296846624 found: 3735928559
2020-10-13 20:46:09 0 [ERROR] InnoDB: Missing MLOG_CHECKPOINT at 41797373564 between the checkpoint 41797373564 and the end 41797373440.
2020-10-13 20:46:09 0 [ERROR] InnoDB: Plugin initialization aborted with error Generic error
2020-10-13 20:46:09 0 [Note] InnoDB: Starting shutdown...
2020-10-13 20:46:09 0 [ERROR] Plugin 'InnoDB' init function returned error.
2020-10-13 20:46:09 0 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
2020-10-13 20:46:09 0 [Note] Plugin 'FEEDBACK' is disabled.
2020-10-13 20:46:09 0 [Note] CONNECT: Version 1.06.0009 January 27, 2019
2020-10-13 20:46:09 0 [ERROR] Unknown/unsupported storage engine: InnoDB
2020-10-13 20:46:09 0 [ERROR] Aborting

So now I'm a bit stumped at the lack of diagnostic messages. Is there any way to coax more info out of mysqld when it goes down? Or should I just start incrementing innodb_force_recovery until something interesting happens?
it s clearly telling you that it looks for INNOdb driver and can not find it.
that means that your filesystem can not read the needed files. try to repair the installation, if they are missing or look for the reason.