Likely caused by my recent changes, although I haven't found an obvious commit, and can't reproduce the error when running manually. This is breaking my job but also seems to affect other reports.
2021-06-01 06:27:56,676 - INFO - Executing "<Report key=users_codemirror_and_wikitext type=sql granularity=day ...
2021-06-01 06:28:12,710 - ERROR - Report "users_codemirror_and_wikitext" could not be written because of error
'NoneType' object has no attribute 'strftime'
Traceback (most recent call last):
File "/srv/reportupdater/reportupdater/reportupdater/writer.py", line 45, in run
self.write_results(header, updated_data, report, self.get_output_folder())
File "/srv/reportupdater/reportupdater/reportupdater/writer.py", line 148, in write_results
row[0] = row[0].strftime(DATE_FORMAT)
AttributeError: 'NoneType' object has no attribute 'strftime'