提前感谢您的帮助！
我正在尝试使用 Pip 1.5.2 安装一组 Python 2.7.5 库。我正在按照说明在我的 mac (OS X Mavericks) 上安装 NuPIC。在我运行这条线之前，一切都很好：
sudo pip install --allow-all-external --allow-unverified PIL --allow-unverified psutil -r $NUPIC/external/common/requirements.txt
我收到了这个错误：
building '_imagingft' extension
cc -fno-strict-aliasing -fno-common -dynamic -arch x86_64 -arch i386 -g -Os -pipe -fno-common -fno-strict-aliasing -fwrapv -mno-fused-madd -DENABLE_DTRACE -DMACOSX -DNDEBUG -Wall -Wstrict-prototypes -Wshorten-64-to-32 -DNDEBUG -g -fwrapv -Os -Wall -Wstrict-prototypes -DENABLE_DTRACE -arch x86_64 -arch i386 -pipe -I/System/Library/Frameworks/Tcl.framework/Headers -I/System/Library/Frameworks/Tk.framework/Headers -I/usr/local/include/freetype2 -IlibImaging -I/System/Library/Frameworks/Python.framework/Versions/2.7/include -I/usr/local/include -I/usr/include -I/System/Library/Frameworks/Python.framework/Versions/2.7/include/python2.7 -c _imagingft.c -o build/temp.macosx-10.9-intel-2.7/_imagingft.o
clang: warning: argument unused during compilation: '-mno-fused-madd'
_imagingft.c:73:10: fatal error: 'freetype/fterrors.h' file not found
#include <freetype/fterrors.h>
^
1 error generated.
error: command 'cc' failed with exit status 1
----------------------------------------
Cleaning up...
Command /usr/bin/python -c "import setuptools, tokenize;__file__='/private/tmp/pip_build_root/PIL/setup.py';exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --record /tmp/pip-vJHHeE-record/install-record.txt --single-version-externally-managed --compile failed with error code 1 in /private/tmp/pip_build_root/PIL
Storing debug log for failure in /Users/aaronclaytondunn/Library/Logs/pip.log
这是需求文件（$NUPIC/external/common/requirements.txt）：
#See http://www.pip-installer.org/en/latest/requirements.html for details
asteval==0.9.1
mock==1.0.1
ordereddict==1.1
PIL==1.1.7
psutil==1.0.1
pylint==0.28.0
pytest==2.4.2
pytest-cov==1.6
pytest-xdist==1.8
python-dateutil==2.1
PyYAML==3.10
unittest2==0.5.1
validictory==0.9.1
PyMySQL==0.5
DBUtils==1.1
numpy==1.7.1
tweepy==2.1
它有一段时间运行良好，所以我认为它成功安装了一些库并打破了一个。任何想法出了什么问题？