old_contents: from distutils.core import Extension
  from os.path import join
  import sys
  
  
  def get_extensions(build_type='release'):
      EXPAT_DIR = 'cextern/expat/lib'
      XML_DIR = 'astropy/utils/xml/src'
  
      defines = [("HAVE_EXPAT_CONFIG_H", 1)]
      if sys.byteorder == 'big':
          defines.append(('BYTEORDER', '4321'))
      else:
          defines.append(('BYTEORDER', '1234'))
      if sys.platform != 'win32':
          defines.append(('HAVE_UNISTD_H', None))
  
      if sys.platform.startswith('linux'):
          # This is to ensure we only export the Python entry point
          # symbols and the linker won't try to use the system expat in
          # place of ours.
          extra_link_args = [
              '-Wl,--version-script={0}'.format(
                  join(XML_DIR, '_iterparser.vers'))
              ]
      else:
          extra_link_args = []
  
      return [Extension(
          "astropy.utils.xml._iterparser",
          [join(XML_DIR, "iterparse.c"),
           join(EXPAT_DIR, "xmlparse.c"),
           join(EXPAT_DIR, "xmlrole.c"),
           join(EXPAT_DIR, "xmltok.c"),
           join(EXPAT_DIR, "xmltok_impl.c")],
          define_macros=defines,
          include_dirs=[XML_DIR, EXPAT_DIR],
          extra_link_args=extra_link_args)]
  
new_contents: from distutils.core import Extension
  from os.path import join
  import sys
  
  
  def get_extensions(build_type='release'):
      EXPAT_DIR = 'cextern/expat/lib'
      XML_DIR = 'astropy/utils/xml/src'
  
      defines = [("HAVE_EXPAT_CONFIG_H", 1)]
      if sys.byteorder == 'big':
          defines.append(('BYTEORDER', '4321'))
      else:
          defines.append(('BYTEORDER', '1234'))
      if sys.platform != 'win32':
          defines.append(('HAVE_UNISTD_H', None))
  
      if sys.platform.startswith('linux'):
          # This is to ensure we only export the Python entry point
          # symbols and the linker won't try to use the system expat in
          # place of ours.
          extra_link_args = [
              '-Wl,--version-script={0}'.format(
                  join(XML_DIR, 'iterparse.map'))
              ]
      else:
          extra_link_args = []
  
      return [Extension(
          "astropy.utils.xml._iterparser",
          [join(XML_DIR, "iterparse.c"),
           join(EXPAT_DIR, "xmlparse.c"),
           join(EXPAT_DIR, "xmlrole.c"),
           join(EXPAT_DIR, "xmltok.c"),
           join(EXPAT_DIR, "xmltok_impl.c")],
          define_macros=defines,
          include_dirs=[XML_DIR, EXPAT_DIR],
          extra_link_args=extra_link_args)]
  
subject: Fix typo