logger string formatting type errors

[FoamyGuy]

Running circup.py commands under python 3.7 on Win7 I end up with a bunch of errors like this printed:

Message: 'Current library bundle up to date ({}).'
Arguments: ('20200801',)
--- Logging error ---
Traceback (most recent call last):
  File "C:\Users\o_O\AppData\Local\Programs\Python\Python37-32\lib\logging\__init__.py", line 983, in emit
    msg = self.format(record)
  File "C:\Users\o_O\AppData\Local\Programs\Python\Python37-32\lib\logging\__init__.py", line 829, in format
    return fmt.format(record)
  File "C:\Users\o_O\AppData\Local\Programs\Python\Python37-32\lib\logging\__init__.py", line 569, in format
    record.message = record.getMessage()
  File "C:\Users\o_O\AppData\Local\Programs\Python\Python37-32\lib\logging\__init__.py", line 331, in getMessage
    msg = msg % self.args
TypeError: not all arguments converted during string formatting

that all point back to lines of code in circup like logger.info("some string {}", some_var).

It seems that the logger module is not using the new style template replacements {} but instead may be expecting %s. This answer on Stack overflow points the issue and solution: https://stackoverflow.com/a/12843139/507810