O sistema inicializa normalmente e eu entro. Eu abro um xterm e isso acontece:
$ groups
rphelps
$ su rphelps
Password:
$ groups
rphelps adm cdrom sudo dip www-data plugdev lpadmin sambashare kismet docker
Se eu fizer login via SSH, meus grupos estão definidos corretamente. Se eu fizer login em um tty em vez de X, meus grupos estão configurados corretamente.
Quando tento sair da sessão X ou pressionar Ctrl + Alt + L, ela fecha a sessão, mas parece que a saudação não pode ser (re) iniciada ou a lockscreen não funciona, e me traz de volta ao meu desktop .
Recentemente eu estava me debatendo com protetores de tela (xscreensaver, gnome-screensaver, etc.) tentando fazer a tela travar depois de 30 minutos (sem sorte). Purgar aqueles removeram algo vital para sair?
Eu não modifiquei nenhum arquivo /etc/ manualmente.
Xubuntu 18.04
Editar 1:
$ journalctl -u lightdm.service
-- Reboot --
Jul 25 11:21:01 rphelps-DELL systemd[1]: Starting Light Display Manager...
Jul 25 11:21:01 rphelps-DELL lightdm[993]: Seat type 'xlocal' is deprecated, use 'type=local' instead
Jul 25 11:21:01 rphelps-DELL systemd[1]: Started Light Display Manager.
Jul 25 11:21:02 rphelps-DELL lightdm[1179]: pam_kwallet(lightdm-greeter:setcred): (null): pam_sm_setcred
Jul 25 11:21:02 rphelps-DELL lightdm[1179]: pam_kwallet5(lightdm-greeter:setcred): (null): pam_sm_setcred
Jul 25 11:21:02 rphelps-DELL lightdm[1179]: pam_unix(lightdm-greeter:session): session opened for user lightdm by (uid=0)
Jul 25 11:21:03 rphelps-DELL lightdm[1179]: pam_kwallet(lightdm-greeter:session): (null): pam_sm_open_session
Jul 25 11:21:03 rphelps-DELL lightdm[1179]: pam_kwallet(lightdm-greeter:session): pam_kwallet: open_session called without kwallet_key
Jul 25 11:21:03 rphelps-DELL lightdm[1179]: pam_kwallet5(lightdm-greeter:session): (null): pam_sm_open_session
Jul 25 11:21:03 rphelps-DELL lightdm[1179]: pam_kwallet5(lightdm-greeter:session): pam_kwallet5: open_session called without kwallet5_key
Jul 25 11:21:03 rphelps-DELL lightdm[1854]: pam_succeed_if(lightdm:auth): incomplete condition detected
Jul 25 11:22:37 rphelps-DELL lightdm[1854]: pam_kwallet(lightdm:auth): (null): pam_sm_authenticate
Jul 25 11:22:37 rphelps-DELL lightdm[1854]: pam_kwallet5(lightdm:auth): (null): pam_sm_authenticate
Jul 25 11:22:37 rphelps-DELL lightdm[1854]: pam_kwallet(lightdm:setcred): pam_kwallet: pam_sm_setcred
Jul 25 11:22:37 rphelps-DELL lightdm[1854]: pam_kwallet5(lightdm:setcred): pam_kwallet5: pam_sm_setcred
Jul 25 11:22:37 rphelps-DELL lightdm[1854]: pam_unix(lightdm:session): session opened for user rphelps by (uid=0)
Jul 25 11:22:37 rphelps-DELL lightdm[1854]: pam_kwallet(lightdm:session): pam_kwallet: pam_sm_open_session
Jul 25 11:22:37 rphelps-DELL lightdm[993]: Error writing to daemon: Bad file descriptor
Jul 25 11:22:37 rphelps-DELL lightdm[993]: Failed to write utmpx: Permission denied
Jul 25 11:34:02 rphelps-DELL lightdm[993]: Failed to write utmpx: Permission denied
Jul 25 11:34:02 rphelps-DELL lightdm[993]: Error writing to daemon: Bad file descriptor
Jul 25 11:34:02 rphelps-DELL lightdm[993]: Failed to write utmpx: Permission denied
Jul 25 11:40:38 rphelps-DELL lightdm[993]: Failed to write utmpx: Permission denied
Jul 25 11:40:38 rphelps-DELL lightdm[993]: Error writing to daemon: Bad file descriptor
Jul 25 11:40:38 rphelps-DELL lightdm[993]: Failed to write utmpx: Permission denied
Jul 25 11:50:05 rphelps-DELL lightdm[993]: Failed to write utmpx: Permission denied
Jul 25 11:50:05 rphelps-DELL systemd[1]: Stopping Light Display Manager...
Jul 25 11:50:05 rphelps-DELL lightdm[993]: Error updating user /org/freedesktop/Accounts/User1000: GDBus.Error:org.freedesktop.systemd1.ShuttingDown: Refusing
Jul 25 11:50:05 rphelps-DELL lightdm[993]: seat_lock: assertion 'seat != NULL' failed
Jul 25 11:50:05 rphelps-DELL lightdm[993]: Error updating user /org/freedesktop/Accounts/User1000: GDBus.Error:org.freedesktop.systemd1.ShuttingDown: Refusing
Jul 25 11:50:05 rphelps-DELL lightdm[993]: Error updating user /org/freedesktop/Accounts/User1000: GDBus.Error:org.freedesktop.systemd1.ShuttingDown: Refusing
Jul 25 11:50:07 rphelps-DELL systemd[1]: Stopped Light Display Manager.