> I just figured out the problem: I'm using a smartcard (specifically, a > YubiKey Neo). If the smartcard is not inserted, I get the error. It > would be better if I instead got a prompt to insert the smartcard with > the specified key. This problem have been reported, but it seems no progress. https://debbugs.gnu.org/cgi/bugreport.cgi?bug=13193 -- Kazuhiro Ito