title: Cython Compilation Error: dynamic module does not define module export function
body: <p>I am building a package in Cython. I am using the following as the structure for <code>setup.py</code>:</p>
  
  <pre><code>from distutils.core import setup
  from distutils.extension import Extension
  from Cython.Build import cythonize
  import numpy
  import scipy
  
  extensions = [
      Extension("xxxxx",["xxxx/xxxxx.pyx"],
      include_dirs=[numpy.get_include(),"."]),
      Extension("nnls",["xxxxx/xxxxx.pyx"],
                include_dirs=[numpy.get_include(),"."]),
  ]
  
  setup(
      name='xxxxxx',
      version='0.0.0',
      description='''********''',
      url='xxxxxxx',
      author='xxxxx',
      author_email='xxxxx',
      packages=[
          'xxxxx',
      ],
      install_requires=[
          'cython',
          'numpy',
          'scipy',
      ],
      ext_modules=cythonize(extensions),
  )
  </code></pre>
  
  <p>However, I am getting an error upon installation in Python 3. It is working in Python 2 however, it is not compiling in Python 3 having the following error:</p>
  
  <blockquote>
    <p>dynamic module does not define module export function</p>
  </blockquote>
  
  <p>How can I solve this problem? Is the structure of the <code>setup.py</code> the reason why this is not compiling? </p>