bug#49714: 28.0.50; TRAMP burns CPU and has insufficient user reporting when using xxxx-sk SSH keys

[Michael Albinus]

[Adding debbugs to Cc]

Dima Kogan <dima@secretsauce.net> writes:

Hi Dima,

I've pushed the recent changes to master (slightly modified).

> Really close now. Everything works generally, but I see one issue:
>
> The state of emacs during the "Confirm user presence" request is odd.
> The "Confirm user presence" text does appear at the bottom. But the
> modeline, point and margins are not rendered, and emacs generally isn't
> responsive. Visually it looks like the program crashed, although it
> hasn't: I can C-g or I can touch the yubikey.

Well, while you see the message, Tramp is looping with
accept-process-output in order to check, whether the yubikey has been
pressed. This is not different from everything else Tramp does, until
the remote shell prompt has been detected. So I don't see what we could
do otherwise ...

Btw, there is a timeout of 30 seconds. When you don't press the yubikey
during this time, Tramp shall cancel the authentication process. Perhaps
you could give this also a short test?

Best regards, Michael.