secondplanet/homebrew — comment on commit 247aba11943ca71ea995d800de0d40390950c6c8
File: Library/Formula/brew-growl.rb line 9
By secondplanet:

No; `brew-growl` uses an alias hack that overrides the `brew` command, so the script cannot actually use Homebrew to detect the location. So

brew install # becomes brew growl install
brew uninstall # becomes brew growl install
brew --prefix # becomes brew growl --prefix

and so on. So, the path has to be given directly otherwise the path is not found.