This doesn't work with OS X 10.9 or later. If you want to build gdb-ng either use Mountain Lion or ask gdbinit (github)/osxreverser (twitter)/fractalg (irc) to fix it for you ;^)
Install darwinbuild
:
sudo port install darwinbuild
Download and pack gdb-ng
:
cd /tmp
wget --no-check-certificate https://github.com/gdbinit/gdb-ng/archive/master.zip