old_contents: {
    'targets': [
      {
        'target_name': 'binding',
        'sources': [
          'src/binding.cc'
        ],
        'include_dirs': ['/usr/include/postgresql'],
        'libraries' : ['-lpq']
      }
    ]
  }
  
new_contents: {
    'targets': [
      {
        'target_name': 'binding',
        'sources': [
          'src/binding.cc'
        ],
        'include_dirs': ['<!@(pg_config --includedir)'],
        'libraries' : ['-lpq -L<!@(pg_config --libdir)']
      }
    ]
  }
  
subject: Use pg_config in bindings.gyp