title: elastic beanstalk deploy has error
body: <p>I want to deploy my code to elastic beanstalk,    </p>
  
  <p>There is error:</p>
  
  <p>And I don't know what's the problem,Please help me. Thank you!!  </p>
  
  <pre><code>Command /opt/python/run/venv/bin/python27 -c "import setuptools, tokenize;__file__='/opt/python/run/venv/build/lxml/setup.py';exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --record /tmp/pip-tgTtHY-record/install-record.txt --single-version-externally-managed --compile --install-headers /opt/python/run/venv/include/site/python2.7 failed with error code 1 in /opt/python/run/venv/build/lxml
  Storing debug log for failure in /root/.pip/pip.log
  2015-01-13 06:25:55,467 ERROR    Error installing dependencies: Command '/opt/python/run/venv/bin/pip install --use-mirrors -r /opt/python/ondeck/app/requirements.txt' returned non-zero exit status 1
  Traceback (most recent call last):
    File "/opt/elasticbeanstalk/hooks/appdeploy/pre/03deploy.py", line 36, in main
      install_dependencies()
    File "/opt/elasticbeanstalk/hooks/appdeploy/pre/03deploy.py", line 31, in install_dependencies
      check_call('%s install --use-mirrors -r %s' % (os.path.join(APP_VIRTUAL_ENV, 'bin', 'pip'), requirements_file), shell=True)
    File "/usr/lib64/python2.6/subprocess.py", line 505, in check_call
      raise CalledProcessError(retcode, cmd)
  CalledProcessError: Command '/opt/python/run/venv/bin/pip install --use-mirrors -r /opt/python/ondeck/app/requirements.txt' returned non-zero exit status 1 (Executor::NonZeroExitStatus)
  </code></pre>
  
  <p>.ebextensions/01.config</p>
  
  <pre><code>packages:
      yum:
          gcc: ''
          python27-devel: ''
          postgresql93-devel: ''
          pkgconfig: ''
          libffi-devel: ''
          libxslt-devel: ''
          libxml2-devel: ''
  </code></pre>