我使用Mac（OS X 10.11.5）。我想pymssql为python安装模块。在Terminal.app我输入sudo -H pip install pymssql，pip install pymssql，sudo pip install pymssql。但是会发生错误。

该目录/Users/janghyunsoo/Library/Caches/pip/http或其父目录不属于当前用户，并且缓存已被禁用。请检查该目录的权限和所有者。如果执行pip有sudo，你可能想sudo的-H标志。

该目录/Users/janghyunsoo/Library/Caches/pip或其父目录不属于当前用户，并且缓存轮已被禁用。检查该目录的权限和所有者。如果执行pip有sudo，你可能想sudo的-H标志。

Collecting pymssql
  Downloading pymssql-2.1.2.tar.gz (898kB)
    100% |████████████████████████████████| 901kB 955kB/s 
Installing collected packages: pymssql
  Running setup.py install for pymssql ... error
    Complete output from command /Library/Frameworks/Python.framework/Versions/2.7/Resources/Python.app/Contents/MacOS/Python -u -c "import setuptools, tokenize;__file__='/private/tmp/pip-build-KA5ksi/pymssql/setup.py';exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --record /tmp/pip-A3wRBy-record/install-record.txt --single-version-externally-managed --compile:
    setup.py: platform.system() => 'Darwin'
    setup.py: platform.architecture() => ('64bit', '')
    setup.py: platform.libc_ver() => ('', '')
    setup.py: Detected Darwin/Mac OS X.
        You can install FreeTDS with Homebrew or MacPorts, or by downloading
        and compiling it yourself.

        Homebrew (http://brew.sh/)
        --------------------------
        brew install freetds

        MacPorts (http://www.macports.org/)
        -----------------------------------
        sudo port install freetds

    setup.py: Not using bundled FreeTDS
    setup.py: include_dirs = ['/usr/local/include', '/opt/local/include', '/opt/local/include/freetds']
    setup.py: library_dirs = ['/usr/local/lib', '/opt/local/lib']
    running install
    running build
    running build_ext
    building '_mssql' extension
    creating build
    creating build/temp.macosx-10.6-intel-2.7
    /usr/bin/clang -fno-strict-aliasing -fno-common -dynamic -arch i386 -arch x86_64 -g -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -I/usr/local/include -I/opt/local/include -I/opt/local/include/freetds -I/Library/Frameworks/Python.framework/Versions/2.7/include/python2.7 -c _mssql.c -o build/temp.macosx-10.6-intel-2.7/_mssql.o -DMSDBLIB
    _mssql.c:18924:15: error: use of undeclared identifier 'DBVERSION_80'
        __pyx_r = DBVERSION_80;
                  ^
    1 error generated.
    error: command '/usr/bin/clang' failed with exit status 1

    ----------------------------------------
Command "/Library/Frameworks/Python.framework/Versions/2.7/Resources/Python.app/Contents/MacOS/Python -u -c "import setuptools, tokenize;__file__='/private/tmp/pip-build-KA5ksi/pymssql/setup.py';exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --record /tmp/pip-A3wRBy-record/install-record.txt --single-version-externally-managed --compile" failed with error code 1 in /private/tmp/pip-build-KA5ksi/pymssql/