> Homebrew is working on an official Rust frontend that will actually have full compatibility.

When you say "Rust frontend", is the vision that Homebrew's frontend would eventually transition to being a pure Rust project — no end-user install of portable-ruby and so forth?

If so (ignore everything below if not):

I can see how that would work for most "boring" formulae: formula JSON gets pre-baked at formula publish time; Rust frontend pulls it; discovers formula is installable via bottle; pulls bottle; never needs to execute any Ruby.

But what happens in the edge-cases there — formulae with no bottles, Ruby `post_install` blocks, and so forth? (And also, how is local formula development done?)

Is the ultimate aim of this effort, to build and embed a tiny little "Formula Ruby DSL" interpreter into the Rust frontend, that supports just enough of Ruby's syntax + semantics to execute the code that appears in practice in the bodies of real formulae methods/blocks? (I personally think that would be pretty tractable, but I imagine you might disagree.)