old_contents: #!/usr/bin/env python
  import os
  from setuptools import setup
  from setuptools.extension import Extension
  import re
  
  import numpy
  
  if os.path.exists("extinction.pyx"):
      USE_CYTHON = True
      fname = "extinction.pyx"
  else:
      USE_CYTHON = False
      fname = "extinction.c"
  
  sourcefiles = [fname, os.path.join("extern", "bs.c")]
  dependsfiles = [os.path.join("extern", "bs.h"),
                  os.path.join("extern", "bsplines.pxi")]
  include_dirs = [numpy.get_include(), "extern"]
  extensions = [Extension("extinction", sourcefiles, include_dirs=include_dirs,
                          depends=dependsfiles)]
  
  if USE_CYTHON:
      from Cython.Build import cythonize
      extensions = cythonize(extensions)
  
  # Synchronize version from code.
  version = re.findall(r"__version__ = \"(.*?)\"", open(fname).read())[0]
  
  classifiers = [
      "Development Status :: 3 - Alpha",
      "Programming Language :: Python :: 2",
      "Programming Language :: Python :: 3",
      "License :: OSI Approved :: MIT License",
      "Topic :: Scientific/Engineering :: Astronomy",
      "Intended Audience :: Science/Research"]
  
  setup(name="extinction", 
        version=version,
        description="Fast interstellar dust extinction laws",
        long_description="documentation: http://extinction.readthedocs.io",
        license="MIT",
        classifiers=classifiers,
        url="http://github.com/kbarbary/extinction",
        author="Kyle Barbary",
        author_email="kylebarbary@gmail.com",
        ext_modules=extensions,
        install_requires=["numpy"])
  
new_contents: #!/usr/bin/env python
  import os
  from setuptools import setup
  from setuptools.extension import Extension
  import re
  
  import numpy
  
  if os.path.exists("extinction.pyx"):
      USE_CYTHON = True
      fname = "extinction.pyx"
  else:
      USE_CYTHON = False
      fname = "extinction.c"
  
  sourcefiles = [fname, os.path.join("extern", "bs.c")]
  dependsfiles = [os.path.join("extern", "bs.h"),
                  os.path.join("extern", "bsplines.pxi")]
  include_dirs = [numpy.get_include(), "extern"]
  extensions = [Extension("extinction", sourcefiles, include_dirs=include_dirs,
                          depends=dependsfiles, extra_compile_args=['-std=c99'])]
  
  if USE_CYTHON:
      from Cython.Build import cythonize
      extensions = cythonize(extensions)
  
  # Synchronize version from code.
  version = re.findall(r"__version__ = \"(.*?)\"", open(fname).read())[0]
  
  classifiers = [
      "Development Status :: 3 - Alpha",
      "Programming Language :: Python :: 2",
      "Programming Language :: Python :: 3",
      "License :: OSI Approved :: MIT License",
      "Topic :: Scientific/Engineering :: Astronomy",
      "Intended Audience :: Science/Research"]
  
  setup(name="extinction", 
        version=version,
        description="Fast interstellar dust extinction laws",
        long_description="documentation: http://extinction.readthedocs.io",
        license="MIT",
        classifiers=classifiers,
        url="http://github.com/kbarbary/extinction",
        author="Kyle Barbary",
        author_email="kylebarbary@gmail.com",
        ext_modules=extensions,
        install_requires=["numpy"])
  
subject: add std=c99 to compiler options