old_contents: #!/usr/bin/env python3
  
  import sys
  import time
  
  start = time.time()
  
  for line in sys.stdin:
      seconds = time.time() - start
      sys.stdout.write('%02d:%02d %s' % (seconds // 60, seconds % 60, line))
      sys.stdout.flush()
  
new_contents: #!/usr/bin/env python3.7
  
  import sys
  import time
  
  start = time.time()
  
  sys.stdin.reconfigure(errors='surrogateescape')
  sys.stdout.reconfigure(errors='surrogateescape')
  
  for line in sys.stdin:
      seconds = time.time() - start
      sys.stdout.write('%02d:%02d %s' % (seconds // 60, seconds % 60, line))
      sys.stdout.flush()
  
subject: Make Shippable timing script more resilient.