old_contents: #!/usr/bin/env python
  
  import sys
  import os.path
  import site
  
  def main():
      '''\
      Check if the given prefix is included in sys.path for the given
      python version; if not find an alternate valid prefix.  Print the
      result to standard out.
      '''
      if len(sys.argv) != 3:
          msg = 'usage: %s <prefix> <python version>\n' % \
                os.path.basename(sys.argv[0])
          sys.stderr.write(msg)
          return 1
      python_prefix = sys.argv[1]
      python_version = sys.argv[2]
      path = '%s/lib/python%s' % (python_prefix, python_version)
      path = os.path.normpath(path)
      if path[-1] != '/':
          path = path + '/'
      prefix = None
      for p in sys.path:
          if p.startswith(path):
              prefix = path
              break
      if not prefix:
          prefix = site.PREFIXES[-1]
      sys.stdout.write('%s\n' % prefix)
      return 0
  
  if __name__ == '__main__':
      sys.exit(main())
  
new_contents: #!/usr/bin/env python
  
  import sys
  import os.path
  import site
  
  def main():
      '''\
      Check if the given prefix is included in sys.path for the given
      python version; if not find an alternate valid prefix.  Print the
      result to standard out.
      '''
      if len(sys.argv) != 3:
          msg = 'usage: %s <prefix> <python version>\n' % \
                os.path.basename(sys.argv[0])
          sys.stderr.write(msg)
          return 1
      python_prefix = sys.argv[1]
      python_version = sys.argv[2]
      path = '%s/lib/python%s' % (python_prefix, python_version)
      path = os.path.normpath(path)
      if path[-1] != '/':
          path = path + '/'
      prefix = None
      for p in sys.path:
          if p.startswith(path):
              prefix = python_prefix
              break
      if not prefix:
          prefix = site.PREFIXES[-1]
      sys.stdout.write('%s\n' % prefix)
      return 0
  
  if __name__ == '__main__':
      sys.exit(main())
  
subject: Fix typo in previous commit.