g/namespace_packages/s//#&/
/^USE_SYSTEM_FFI /s/=.*/= True/
/^USE_SYSTEM_LIBXML /s/=.*/= True/
a

SDKROOT = os.environ.get('SDKROOT')
if SDKROOT is None or SDKROOT is '':
    SDKROOT = '/'
.
/os\.path\.exists('\/usr\/include\/objc\/runtime\.h'):$/s/'\/usr\/include\/objc\/runtime\.h'/os.path.join(SDKROOT, 'usr\/include\/objc\/runtime\.h')/
/"-I\/usr\/include\/ffi"/s//'-I' + os.path.join(SDKROOT, "usr\/include\/ffi")/
w