Brew install R fails - Updated right away

I just cleaned up my home brew cellar and had problems reinstalling R. I got the old well-known error message:

brew install r
==> Downloading http://cran.r-project.org/src/base/R-2/R-2.15.1.tar.gz
Already downloaded: /Library/Caches/Homebrew/r-2.15.1.tar.gz
Error: This formula requires a fortran compiler,...

Reinstalling gfortran (which was actually installed already) did not help and so I decided to trick home brew until the problem is fixed, with the following:

export FC=`which gfortran`
brew install r

Surprise surprise, it worked! :]

[Update:] The bug I filed was almost fixed immediately. So the post remains just as a reminder for the future ;)

Cheers,
iss