OSX Homebrew error: uninitialized constant MACOS

Question

I\'ve searched around a bit and can\'t seem to find any record of anyone else with this problem.

Whenever I try to run

$ brew update

Answer 1

In addition to Matt Korostoff's answer. On point 3 (resetting the repo), for recent version of Homebrew, the repo is no longer /usr/local, do cd "$(brew --repo)" instead.