Adding shellcheck in 19c0ad2 exposed a lot of what I thought was portable as bash-isms. Going forward we can either fully adopt bash and probably save quite a bit of frustration, or convert all our bash-isms to portable shell-isms. Both will probably be fun learning experiences, but since this script is so closely tied to MacOS it doesn't benefit from POSIX-compatibility.
Adding shellcheck in 19c0ad2 exposed a lot of what I thought was portable as bash-isms. Going forward we can either fully adopt bash and probably save quite a bit of frustration, or convert all our bash-isms to portable shell-isms. Both will probably be fun learning experiences, but since this script is so closely tied to MacOS it doesn't benefit from POSIX-compatibility.
Or maybe move to zsh? It's been around since Mojave and I've never even touched it.