mxcl/homebrew — pull request #9406 by jacknagel (2012-01-04 05:38:44+00:00)
Title: [RFC] enable easy installation of old versions

So applying these patches will give you `brew versions --install `.

This really belongs in `brew install` somehow, but it was easier to implement a proof of concept in `brew versions`. Also, the command-line argument parsing is pretty fragile, so you have to do `brew versions --install ` and then add any other options (e.g. --verbose).

But here it is.

(Also, `brew versions` now determines the version by writing the formula blob's contents to a temp file and actually loading the formula rather than the complicated regexps that it used before).