old_contents: {
    'targets': [
      {
        'target_name': 'binding',
        'sources': [ 'binding.cc' ],
        'libraries': ['-lzmq'],
        'cflags!': ['-fno-exceptions'],
        'cflags_cc!': ['-fno-exceptions'],
        'conditions': [
          ['OS=="mac"', {
            'xcode_settings': {
              'GCC_ENABLE_CPP_EXCEPTIONS': 'YES'
            }
          }]
        ]
      }
    ]
  }
  
new_contents: {
    'targets': [
      {
        'target_name': 'binding',
        'sources': [ 'binding.cc' ],
        'libraries': ['-lzmq'],
        'cflags!': ['-fno-exceptions'],
        'cflags_cc!': ['-fno-exceptions'],
        'conditions': [
          ['OS=="mac"', {
            'xcode_settings': {
              'GCC_ENABLE_CPP_EXCEPTIONS': 'YES'
            },
            # add macports include & lib dirs
            'include_dirs': [
              '/opt/local/include',
            ],
            'libraries': [
              '-L/opt/local/lib'
            ]
          }]
        ]
      }
    ]
  }
  
subject: add /opt to os x header & lib paths. makes this build under node-gyp on os x w/ zmq from mac ports.