https://bugzilla.wikimedia.org/show_bug.cgi?id=73120
--- Comment #11 from Fabian CommodoreFabianus@gmx.de --- And another: https://travis-ci.org/wikimedia/pywikibot-core/jobs/41313071#L483
This issue is weird as I can't see how something could get stuck, except maybe in httplib so it returns the value on the next request. Unfortunately I don't know how I could disrupt it locally so that I get that error too. I tried throwing exceptions in the loop but it didn't care.