old_contents: import sys
  import platform
  from setuptools import setup, Extension
  
  cpython = platform.python_implementation() == 'CPython'
  is_glibc = platform.libc_ver()[0] == 'glibc'
  libc_ok = is_glibc and platform.libc_ver()[1] >= '2.9'
  windows = sys.platform.startswith('win')
  min_win_version = windows and sys.version_info >= (3, 5)
  min_unix_version = not windows and sys.version_info >= (3, 3)
  
  if cpython and ((min_unix_version and libc_ok) or min_win_version):
      _cbor2 = Extension(
          '_cbor2',
          # math.h routines are built-in to MSVCRT
          libraries=['m'] if not windows else [],
          extra_compile_args=['-std=c99'],
          sources=[
              'source/module.c',
              'source/encoder.c',
              'source/decoder.c',
              'source/tags.c',
              'source/halffloat.c',
          ]
      )
      kwargs = {'ext_modules': [_cbor2]}
  else:
      kwargs = {}
  
  
  setup(
      use_scm_version={
          'version_scheme': 'post-release',
          'local_scheme': 'dirty-tag'
      },
      setup_requires=[
          'setuptools >= 36.2.7',
          'setuptools_scm >= 1.7.0'
      ],
      **kwargs
  )
  
new_contents: import sys
  import platform
  from setuptools import setup, Extension
  
  cpython = platform.python_implementation() == 'CPython'
  is_glibc = platform.libc_ver()[0] == 'glibc'
  if is_glibc:
      glibc_ver = platform.libc_ver()[1]
      libc_numeric = tuple(int(x) for x in glibc_ver.split('.') if x.isdigit())
      libc_ok = libc_numeric >= (2, 9)
  else:
      libc_ok = False
  windows = sys.platform.startswith('win')
  min_win_version = windows and sys.version_info >= (3, 5)
  min_unix_version = not windows and sys.version_info >= (3, 3)
  
  if cpython and ((min_unix_version and libc_ok) or min_win_version):
      _cbor2 = Extension(
          '_cbor2',
          # math.h routines are built-in to MSVCRT
          libraries=['m'] if not windows else [],
          extra_compile_args=['-std=c99'],
          sources=[
              'source/module.c',
              'source/encoder.c',
              'source/decoder.c',
              'source/tags.c',
              'source/halffloat.c',
          ]
      )
      kwargs = {'ext_modules': [_cbor2]}
  else:
      kwargs = {}
  
  
  setup(
      use_scm_version={
          'version_scheme': 'post-release',
          'local_scheme': 'dirty-tag'
      },
      setup_requires=[
          'setuptools >= 36.2.7',
          'setuptools_scm >= 1.7.0'
      ],
      **kwargs
  )
  
subject: Fix glibc version detect string