If you don't run it daily, it takes about a minute or two to update.

But even when it doesn't update, it is extremely slow compared to any other package managers. It is disruptively slow and it takes a lot of resources, even in a powerful machine (and I'm not talking about compilation here).

I do like tools to be as fast as possible, though, and I’d forgotten about that update it does sometimes when I run it - that does seem to take a long time.

I’ll have a look at how it works and see what the things are that take time. I would expect network traffic for updates, perhaps whatever it’s getting updates from does some processing (I’m sure it said something about GitHub), perhaps there is some dependency resolution that needs CPU...

It would be interesting to compare its architecture to other package managers if they’re significantly faster.

99% of the time, installing a package consists of downloading a few zips from their CDN, decompressing and linking. For those cases Brew could just be checking an API instead of constantly cloning the git repository.

I'm quite surprised nobody has reimplemented it in Rust or Go. The architecture is quite simple compared to a normal package manager. Maybe it's just superstition: people see "package manager" and assume it's complicated instead of digging into the code and finding out how it works.

Installing anything with brew involving multiple dependencies is also taking forever-ish, compared to mere seconds with apt.