old_contents: from setuptools import setup, Extension
  from Cython.Build import cythonize
  import numpy
  
  setup(
      name="Shared libraries",
      author="Elliot Marsden",
      author_email="elliot.marsden@gmail.com",
      description="Useful miscellaneous functions and classes.",
      ext_modules=cythonize([
          Extension("field_numerics", ["field_numerics.pyx", ]),
          Extension("walled_field_numerics", ["walled_field_numerics.pyx", ]),
          Extension("geom_numerics", ["geom_numerics.pyx", ]),
          Extension("distance_numerics", ["distance_numerics.pyx", ]),
          Extension("lattice_numerics", ["lattice_numerics.pyx", ]),
      ]),
      include_dirs=[numpy.get_include()],
  )
  
new_contents: from setuptools import setup, Extension
  from Cython.Build import cythonize
  import numpy
  
  setup(
      name="Shared libraries",
      author="Elliot Marsden",
      author_email="elliot.marsden@gmail.com",
      description="Useful miscellaneous functions and classes.",
      ext_modules=cythonize([
          Extension("field_numerics", ["field_numerics.pyx"],
                    include_dirs=[numpy.get_include()]),
          Extension("walled_field_numerics", ["walled_field_numerics.pyx"],
                    include_dirs=[numpy.get_include()]),
          Extension("geom_numerics", ["geom_numerics.pyx"],
                    include_dirs=[numpy.get_include()]),
          Extension("distance_numerics", ["distance_numerics.pyx"],
                    include_dirs=[numpy.get_include()]),
          Extension("lattice_numerics", ["lattice_numerics.pyx"],
                    include_dirs=[numpy.get_include()]),
      ]),
      include_dirs=[numpy.get_include()],
  )
  
  
subject: Change setup script to match updated Cython.