As far as I’m aware, the build script is tailored specifically to building whatever version it provides you. Homebrew does keep older versions of some packages, but
crystal is not one of them. I would suggest that you used
crystal-build to manage your Crystal versions on your machine, rather than relying on homebrew.
That said, crystal-build is sort of in disrepair, and as far as I can tell, still has issues downloading more recent versions of Crystal, and the author doesn’t seem to be doing anything about it. I’m in the process of rewriting crystal-build, but I literally started today so it only does really basic installation of pre-packaged releases from GitHub. Because they’re pre-packaged and not compiled on your machine, you might have some weird library linking issues but it’s nothing that isn’t fixable.
If you decide you want to try it, download
crenv, clone my repo into
~/.crenv/plugins, and build my project with
crystal build --release src/build.cr -o bin/crenv-install. The compiled binary will need to be there in order for
crenv install 0.32.1 to install properly.
That might be a lot to take in, let me know if you need help.
EDIT: Looks like the owner of the
crystal-build repos literally just (10 minutes ago) posted some issues regarding looking for a new maintainer. The future is unclear, I guess.