$ brew doctor
We couldn't detect gcc 4.0.x. Some formulae require this compiler.

/usr/bin is in your PATH before Homebrew's bin. This means that system-
provided programs will be used before Homebrew-provided ones. This is an
issue if you install, for instance, Python.

Consider editing your .bashrc to put:
  /usr/local/bin
ahead of /usr/bin in your $PATH.