Mac OS X, pip: укажите компилятор для пакетов, содержащих библиотеки C

У меня возникли проблемы с компиляцией mapscript (это пакет из pypi, содержащий код C) с помощью компилятора clang по умолчанию с использованием pip.

Вот моя попытка: -

$ sudo pip install mapscript
Password:
Downloading/unpacking mapscript
  Running setup.py egg_info for package mapscript

Requirement already satisfied (use --upgrade to upgrade): distribute in /opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages (from mapscript)
Installing collected packages: mapscript
  Running setup.py install for mapscript

    building '_mapscript' extension
    /opt/local/bin/gcc-apple-4.2 -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -I/opt/local/include -I/opt/local/include -I/opt/local/include -pipe -O2 -arch x86_64 -fPIC -Wall -DNEED_NONBLOCKING_STDERR -DHAVE_VSNPRINTF -DNEED_STRRSTR -DNEED_NONBLOCKING_STDERR -DUSE_WMS_SVR -DUSE_GDAL -DUSE_OGR -DUSE_PROJ -DUSE_EPPL -DUSE_GD_GIF -DUSE_GD_PNG -DUSE_GD_JPEG -DUSE_GD_WBMP -DUSE_GD_FT -DGD_HAS_FTEX_XSHOW -DGD_HAS_GDIMAGEGIFPTR -DGD_HAS_GETBITMAPFONTS -DUSE_ICONV -DUSE_ZLIB -I/opt/local/include -I/opt/local/include -I/opt/local/include -DHAVE_VSNPRINTF -DNEED_STRRSTR -DNEED_NONBLOCKING_STDERR -DUSE_WMS_SVR -DUSE_GDAL -DUSE_OGR -DUSE_PROJ -DUSE_EPPL -DUSE_GD_GIF -DUSE_GD_PNG -DUSE_GD_JPEG -DUSE_GD_WBMP -DUSE_GD_FT -DGD_HAS_FTEX_XSHOW -DGD_HAS_GDIMAGEGIFPTR -DGD_HAS_GETBITMAPFONTS -DUSE_ICONV -DUSE_ZLIB -DHAVE_VSNPRINTF -DNEED_STRRSTR -DNEED_NONBLOCKING_STDERR -DUSE_WMS_SVR -DUSE_GDAL -DUSE_OGR -DUSE_PROJ -DUSE_EPPL -DUSE_GD_GIF -DUSE_GD_PNG -DUSE_GD_JPEG -DUSE_GD_WBMP -DUSE_GD_FT -DGD_HAS_FTEX_XSHOW -DGD_HAS_GDIMAGEGIFPTR -DGD_HAS_GETBITMAPFONTS -DUSE_ICONV -DUSE_ZLIB -I/opt/local/Library/Frameworks/Python.framework/Versions/2.7/include/python2.7 -c mapscript_wrap.c -o build/temp.macosx-10.7-x86_64-2.7/mapscript_wrap.o
    mapscript_wrap.c:2564:23: error: mapserver.h: No such file or directory
    mapscript_wrap.c:2565:25: error: maptemplate.h: No such file or directory
    mapscript_wrap.c:2566:23: error: mapogcsld.h: No such file or directory
...
mapscript_wrap.c:45472: error: 'MS_DEBUGLEVEL_VV' undeclared (first use in this function)

mapscript_wrap.c:45473: error: 'MS_DEBUGLEVEL_VVV' undeclared (first use in this function)

mapscript_wrap.c:45476: error: 'MS_GET_REQUEST' undeclared (first use in this function)

mapscript_wrap.c:45477: error: 'MS_POST_REQUEST' undeclared (first use in this function)

error: command '/opt/local/bin/gcc-apple-4.2' failed with exit status 1

----------------------------------------
Command /opt/local/Library/Frameworks/Python.framework/Versions/2.7/Resources/Python.app/Contents/MacOS/Python -c "import setuptools;__file__='/Users/calvin/build/mapscript/setup.py';exec(compile(open(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --single-version-externally-managed --record /tmp/pip-GYwtAz-record/install-record.txt failed with error code 1
Storing complete log in /Users/calvin/.pip/pip.log

Версия gcc-apple-4.2 -

$ gcc-apple-4.2 --version
i686-apple-darwin11-gcc-apple-4.2.1 (GCC) 4.2.1 (Apple Inc. build 5666) (dot 3)
Copyright (C) 2007 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Как мне попробовать установить mapscript с другим компилятором? Есть ли способ явно указать конкретный компилятор, который будет вызывать pip при компиляции кода C в пакете pypi?