The only reported error, only on Travis, on line 191 is an extra item, 'after#8' (the 'timer' of line 180, I presume), in the tuple returned from .after_info. (The Travis job page somehow disables copying with current Firefox.) On this system, with the tcl/tk used, the preceding root.update() did not remove the 'timer' callback from the list.

I restarted the failing job to see if the failure is repeatable on Travis.

Answer: yes.