Comment 12 for bug 1933027

I finally upgraded to 22.04 and the workaround in my previous message is now also no longer working for me, though it had been in 21.04. Had to remove the YubiKey to log in.

My new workaround is to add an option to the gdm-smartcard alternatives configuration that's just password, no smartcard.

I added the final 2 lines in the file here:

$ cat /var/lib/dpkg/alternatives/gdm-smartcard
manual
/etc/pam.d/gdm-smartcard

/etc/pam.d/gdm-smartcard-pkcs11-exclusive
30
/etc/pam.d/gdm-smartcard-sssd-exclusive
50
/etc/pam.d/gdm-smartcard-sssd-or-password
40
/etc/pam.d/gdm-password
60

$

Now I choose that option using the same command as my previous workaround:

$ sudo update-alternatives --config gdm-smartcard
There are 4 choices for the alternative gdm-smartcard (providing /etc/pam.d/gdm-smartcard).

  Selection Path Priority Status
------------------------------------------------------------
  0 /etc/pam.d/gdm-password 60 auto mode
  1 /etc/pam.d/gdm-smartcard-pkcs11-exclusive 30 manual mode
  2 /etc/pam.d/gdm-smartcard-sssd-exclusive 50 manual mode
  3 /etc/pam.d/gdm-smartcard-sssd-or-password 40 manual mode
* 4 /etc/pam.d/gdm-password 60 manual mode

Press <enter> to keep the current choice[*], or type selection number: 4
$

This is slightly more dangerous than the previous workaround as you may mess up your gdm login completely if you edit the file incorrectly but removing the YubiKey should default you back to just password so you'll be able to fix it.