unknown type name 'sip_t' [Xcode 5]

When trying to install astropy on py2.7 (Homebrew) with Xcode 5, I get a consistent failure during compilation of sip.c

### config

> (test_astropy)<01:21:33> aamn@lynds:astropy-0.2.4 > cc --version
> Apple LLVM version 5.0 (clang-500.2.75) (based on LLVM 3.3svn)
> Target: x86_64-apple-darwin12.5.0
> Thread model: posix

> (test_astropy)<01:21:59> aamn@lynds:astropy-0.2.4 > python --version
> Python 2.7.5

> (test_astropy)<01:28:46> aamn@lynds:astropy-0.2.4 > python -c 'import numpy;print numpy.__version__'
> 1.7.1


### attempts

> pip install --no-deps astropy
> python setup.py build [against 0.2.4 source]

### failure

> cc -fno-strict-aliasing -fno-common -dynamic -I/usr/local/include -I/usr/loo
cal/opt/sqlite/include -isysroot /Applications/Xcode.app/Contents/Developer/Plaa
tforms/MacOSX.platform/Developer/SDKs/MacOSX10.8.sdk -I/Applications/Xcode.app//
Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.8.sdk/Systt
em/Library/Frameworks/Tk.framework/Versions/8.5/Headers -DNDEBUG -g -fwrapv -O33
 -Wall -Wstrict-prototypes -DECHO -DWCSTRIG_MACRO -DASTROPY_WCS_BUILD -D_GNU_SOO
URCE -DWCSVERSION=4.10 -DNDEBUG -UDEBUG -I/Users/aamn/.virtualenvs/test_astropyy
/lib/python2.7/site-packages/numpy/core/include -Iastropy/wcs/include -Icexternn
/wcslib/C -I/usr/local/Cellar/python/2.7.5/Frameworks/Python.framework/Versionss
/2.7/include/python2.7 -c astropy/wcs/src/sip.c -o build/temp.macosx-10.8-x86_66
4-2.7/astropy/wcs/src/sip.o

    astropy/wcs/src/sip.c:16:5: error: unknown type name 'sip_t'; did you mean 'sig_t'?