Would be happy to do that but @mistydemeo in #24063 (cited above) writes:
```
Subformulae are being replaced by the (underdocumented) new Resource feature - you can see an example in svn. However, resources' dependencies are still recommended to be folded into the main formula, and they can't declare their own environment - those are meant to be constant throughout a build.
```
This seems to suggest that a Homebrew resource would not really address the issue, namely the lack of an independent environment (compiler flags etc.) for building Guile. What do you think?