installing lxml in OSX 10.9
Question: I have a problem installing the `lxml` in my mavericks machine.

I tried all possibilities by installing the prebuild binaries using

  * normal pip
  * pip with `static deps`

and Building

  * Current version in normal model
  * Current version with static deps
  * Older version in normal mode
  * Older version with static deps

and always end up in this error.

    
    
    clang: error: unknown argument: '-mno-fused-madd' [-Wunused-command-line-argument-hard-error-in-future]
    clang: note: this will be a hard error (cannot be downgraded to a warning) in the future
    error: command 'cc' failed with exit status 1
    

here the detailed message

    
    
    copying /Users/mangoreader/work/lxml-3.3.4/build/tmp/libxml2/include/libxslt/xsltutils.h -> build/lib.macosx-10.9-intel-2.7/lxml/includes/libxslt
    running build_ext
    building 'lxml.etree' 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/Users/mangoreader/work/lxml-3.3.4/build/tmp/libxml2/include -I/Users/mangoreader/work/lxml-3.3.4/build/tmp/libxml2/include/libxml2 -I/Users/mangoreader/work/lxml-3.3.4/build/tmp/libxml2/include/libxslt -I/Users/mangoreader/work/lxml-3.3.4/build/tmp/libxml2/include/libexslt -I/Users/mangoreader/work/lxml-3.3.4/src/lxml/includes -I/System/Library/Frameworks/Python.framework/Versions/2.7/include/python2.7 -c src/lxml/lxml.etree.c -o build/temp.macosx-10.9-intel-2.7/src/lxml/lxml.etree.o -w -flat_namespace
    clang: error: unknown argument: '-mno-fused-madd' [-Wunused-command-line-argument-hard-error-in-future]
    clang: note: this will be a hard error (cannot be downgraded to a warning) in the future
    error: command 'cc' failed with exit status 1
    

Also when i tried installing `cython` , i am getting the same error

    
    
    clang: error: unknown argument: '-mno-fused-madd' [-Wunused-command-line-argument-hard-error-in-future]
    
    clang: note: this will be a hard error (cannot be downgraded to a warning) in the future
    
    error: command 'cc' failed with exit status 1
    

detailed log here

    
    
    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/Python.framework/Versions/2.7/include/python2.7 -c /private/var/folders/1z/7lv1qq457qxbhkgpt1fk9sdc0000gn/T/pip_build_mangoreader/cython/Cython/Plex/Scanners.c -o build/temp.macosx-10.9-intel-2.7/private/var/folders/1z/7lv1qq457qxbhkgpt1fk9sdc0000gn/T/pip_build_mangoreader/cython/Cython/Plex/Scanners.o
    
    clang: error: unknown argument: '-mno-fused-madd' [-Wunused-command-line-argument-hard-error-in-future]
    
    clang: note: this will be a hard error (cannot be downgraded to a warning) in the future
    
    error: command 'cc' failed with exit status 1
    
    ----------------------------------------
    Cleaning up...
    Command /usr/bin/python -c "import setuptools, tokenize;__file__='/private/var/folders/1z/7lv1qq457qxbhkgpt1fk9sdc0000gn/T/pip_build_mangoreader/cython/setup.py';exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --record /var/folders/1z/7lv1qq457qxbhkgpt1fk9sdc0000gn/T/pip-0akrMB-record/install-record.txt --single-version-externally-managed --compile failed with error code 1 in /private/var/folders/1z/7lv1qq457qxbhkgpt1fk9sdc0000gn/T/pip_build_mangoreader/cython
    Storing debug log for failure in /Users/mangoreader/Library/Logs/pip.log
    

I am totally struck here. It seems this is something to do with the version
conflict with gcc or libxml. But i could't figure out what. Any help much
appreciated.

**SOLVED**

As per this SO post [clang error: unknown argument: '-mno-fused-madd' (python
package installation
failure)](http://stackoverflow.com/questions/22313407/clang-error-unknown-
argument-mno-fused-madd-python-package-installation-fa?rq=1), this can be
fixed by setting up this following env variables

    
    
    export CFLAGS=-Qunused-arguments
    export CPPFLAGS=-Qunused-arguments
    


Answer: I am sure that by that that you sorted it out, but in case someone else needs
it, install XCode and command line tools and just run

    
    
    pip install lxml
    

It will work, may take a little time.

