[R-pkg-devel] Build fails on Mavericks

Hi, I'm having this error when building C functions from a package:

?clang: error: no such file or directory: '/usr/local/lib/libreadline.a'?

Apparently, it's a path issue caused by xcode/gfortran, but I couldn't figure out how to solve it.?
"which gcc" points to "/usr/bin/gcc"
Does someone have any idea on how on this?

Thanks,
Daniel