Comment # 6 on bug 1159972 from Fabian Vogt

(In reply to Maurizio Galli from comment #5)
> (In reply to Fabian Vogt from comment #4)
> > Ok, so pkexec has to pass the XAUTHLOCALHOSTNAME variable.
> 
> So can we confirm that this is a bug in pkexec?

Yes, definitely.