To those unfortunate souls who updated to OS X 10.9 The standard compiler that comes with with xcode 5 is clang and it will give you a ton of troubles.

To fix this (the easiest way) install gnu gcc from Macports. That has received an update for 10.9.

http://www.macports.org/install.php

Be cautious I have heard that Homebrew and Macports does not work very well together.

Then type the following into the terminal: sudo port install gcc48 (or the gcc version number you prefer)

It will probably give you a few errors. Simply do a port install on all the dependancies.

In the end it will give you a "gcc-mp-[version]" binary in /usr/bin simply rename / remove the existing gcc and rename the Macports variant to gcc. (The gcc provided by xcode is just a link to clang anyhow).

Hope it helps! Tomas