How do I run brew install with local changes to the Homebrew source code?
Running brew install discards my changes, even if I've committed them.
More Details
When I run brew install heroku/brew/heroku,
I get:
Error: Xcode alone is not sufficient on High Sierra.
Install the Command Line Tools:
xcode-select --install
However, I don't want to install the Command Line Tools (and I don't want to update macOS right now, and so I can't update Xcode either). So, I edited the Homebrew source code (in /usr/local/Homebrew) to make MacOS::Xcode.needs_clt_installed? (defined in /usr/local/Homebrew/Library/Homebrew/os/mac/xcode.rb) return false.
But, when I run brew install heroku/brew/heroku again, it overwrites my changes to the Homebrew source code.
