this is the same bug that occurred in https://jira.mariadb.org/browse/MDEV-14453. Here's the transcript from IRC #maria:
18:22 < karolyi> hey guys, mariabackup is coredumping for me on Catalina: 'mariabackup -
prepare --target...' terminated by signal SIGABRT (Abort)
18:22 < karolyi> does anyone have an idea as to what this could be?
18:24 < karolyi> I'm using 10.4.10 from homebrew, manually compiled, but the binary version segfaults too
18:27 < karolyi> what da...
18:27 < karolyi> mariabackup --help
18:27 < karolyi> fish: 'mariabackup --help' terminated by signal SIGABRT (Abort)
18:27 < karolyi> but when I call it with its full path, /usr/local/bin/mariabackup --help, works
18:28 < karolyi> what sorcery is this
18:32 < Xgc> karolyi: which mariabackup will show the implicit path.
18:32 < karolyi> with the binary package I get: '/usr/local/bin/mariabackup --he...' terminated by signal SIGSEGV (Address boundary error)
18:32 < karolyi> Xgc: it was that path all along
18:33 < karolyi> I bet this is something Catalina related
18:33 < karolyi> okay, reinstall from source...
18:33 < Xgc> karolyi: Hmmm... That suggests a logic problem in the application. Sometimes the application will take the 0th argument (the name) for some processing. If name contains the full path, maybe some error is avoided.
18:34 < Xgc> At first it seemed like a bad installation (wrong package installed).
18:35 < karolyi> Xgc: the one in /usr/local/bin is a symlink: lrwxr-xr-x 1 laszlokarolyi admin 43 Dec 11 18:07 /usr/local/bin/mariabackup -> ../Cellar/mariadb/10.4.10_1/bin/mariabackup
18:35 < Xgc> or missing prerequisites.
18:35 < karolyi> but interestingly, the binary version fails even when called with full path
18:36 < karolyi> let me try and call it with the path in Cellar
18:36 < karolyi> fish: '/usr/local/Cellar/mariadb/10.4....' terminated by signal SIGSEGV (Address boundary error)
18:37 < karolyi> bash-3.2$ /usr/local/Cellar/mariadb/10.4.10_1/bin/mariabackup --help
18:37 < karolyi> Segmentation fault: 11
18:37 < karolyi> building from source again
18:44 < karolyi> btw I use mbstream and mariabackup extensively to restore previously loaded DBs for development
18:44 < karolyi> so this is why it's a PITA
18:44 < karolyi> https://gist.github.com/karolyi/48e0e7909ae67e9d8f2503bfc3c79225
18:58 < karolyi> okay, so it only works when called with a full path AND compiled from source (binary package segfaults as shown above)
seemingly the bug still persists.