Extract a package without installing it

[lylythechosenone]

Output of brew config

[not relevant]

Output of brew doctor

[not relevant]

Description of issue

I'm trying to do a somewhat cursed thing: putting homebrew packages into the nix store, so that I can make a sort of "ephemeral brew environment" while still keeping a cache. In order to do that, I need to build the packages in a location that can then be given to nix.

My current idea is to make a build directory, copy the (already extracted) homebrew tarball there (to make that into the prefix), run brew install --no-link [formula], get the output path from brew info [formula], and copy everything from there into the output directory.

However, I wanted to ask if there was a way to simply dump a (built) package into the out directory without ever copying the homebrew tarball there. What I envision is a command like brew extract [formula] [path], which would put whatever would normally be in [prefix]/Cellar/... after brew install --no-link [formula] into path instead.

[p-linnane]

Nothing like that currently exists. Your best bet would be to just grab the bottles and extract them where you want them, though this is unsupported.