I see. This isn't clean enough for my tastes. I run Homebrew from a custom directory, not /usr/local, and I want to make GPGMail refer to the gpg binary there. No Mac app installer should ever write anything to /usr/local.

PS: If you are a maintainer, thank you for all the hard work. I'm only criticizing the current installation system because I really want to use GPGMail, and it does not fit into the way I like to set up my machine.