If you specify wrong email address when you update Google App Engine application you might lock your self out for some time. That happened to me today when I was deploying application to company’s GAE account but by mistake logged in my private Google credentials. Obviously, appcfg.py failed early and did not upload application but I could not start upload even after I retried specifying –email option with valid email (I would consider this Google’s bug).
Anyway, I recovered after finding and deleting the following two files in my home folder:
(I’m not sure if deletion of the second file was necesarry.)
Hope this helps someone.