如何为RStudio定制R位置?

I previously used homebrew to install R and the package installer for RStudio. Recently I started using Boxen, which takes over homebrew. I had to re-install R from source using homebrew, and it now exists in my Boxen Cellar location. Now RStudio no longer launches, saying "Unable to locate R binary by scanning standard locations". I tried reinstalling RStudio (I needed to upgrade anyway) but that didn't help. It doesn't even open for long enough to let you specify a custom location.I previously used homebrew to install R and the