https://bugzilla.wikimedia.org/show_bug.cgi?id=55140
--- Comment #1 from Kunal Mehta (Legoktm) legoktm.wikipedia@gmail.com --- I'm also have similar problem.
After updating pywikibot framework, forcing login is somewhat strange.
When bot name differ by project (E.g, different name for local wiki and meta/commons wiki), login is requested for local bot name in meta wiki.
------------------------------------------------------------------------ Pywikibot [http] branches/rewrite (r11617, 2013/06/02, 13:07:05, OUTDATED) Python 2.6.5 (r265:79063, Oct 1 2012, 22:04:36) [GCC 4.4.3] unicode test: ok