old_contents: #!/usr/bin/env python
  
  import sys
  
  # Currently any print-out from the custom tool is interpreted as a crash
  # (i.e. test is still interesting)
  
  print "Error: " + ' '.join(sys.argv[1:])
  
  sys.exit(1)
  
new_contents: #!/usr/bin/env python
  
  import sys
  
  # Currently any print-out from the custom tool is interpreted as a crash
  # (i.e. test is still interesting)
  
  print("Error: " + ' '.join(sys.argv[1:]))
  
  sys.exit(1)
  
subject: Make it py3-compatible. [PR19112]