Except for loading the Ruby VM. Takes way too long.

Which is why for certain things like `brew --prefix` we now do it purely in Bash rather than using Ruby ;)

Why would bash be faster ? Would not you essentially call the same C lib stuff anyway ?

It would at least save the process-start overhead, plus loading the ruby vm and modules/gems.

Exactly. For a simple string comparison Bash is far faster (although Homebrew doesn't use require any gems, just FYI).

Good to know, so did the speedup come mostly from not spinning-up the Ruby VM?

Yep!

I guess it's a start. But even still, the most basic of commands take a good 1+ seconds on my machine. What about Ruby makes it necessary to use? What is stopping you guys from moving to something like LuaJIT?

Rewriting the entire project in non-Ruby would require a lot of time and create a lot of bugs for little benefit for most users.

Unfortunate.