I posted the solution here: https://stackoverflow.com/a/52298389/567193
This looks like a breaking change to me - it would be great if there was an RSS feed I could subscribe to to get notified of such changes. -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/google-appengine. To view this discussion on the web visit https://groups.google.com/d/msgid/google-appengine/0e115025-d5ab-445f-a936-ab3e0f1fd8d4%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
