Created attachment 160002 [details]
upgrade log from pacman

SUMMARY

I ran a full upgrade on my Arch Linux system. This upgraded KDE components from 5.27.5 to 5.27.6 and Qt from 5.15.9 to 5.15.10.

After this upgrade, my selected keyboard layout (dvorak) was broken in KDE. Oddly, possibly as a side effect of this, all "advanced" keyboard behavior (anything in the advanced tab of the keyboard KCM) was broken as well. For example, I have the Caps Lock key configured to be an additional Menu key, but pressing that key only activated caps lock after the upgrade.

I've included the full Pacman log from the upgrade in case it's somehow relevant.

NOTES

 * I normally have a layout switcher with two layouts visible on my taskbar, thanks to the keyboard layout widget. This widget was entirely hidden because only one layout was active (US Qwerty).

 * Going into the keyboard layout setting and removing all layouts except Dvorak from my configured layouts did not solve the problem. Even with US (Qwerty) removed, my keyboard behaved like US Qwerty and advanced configuration didn't work.

RESOLUTION / WORKAROUND

I was able to solve the problem by removing the dvorak layout and then re-adding it to my configuration. This also fixed the advanced behavior. I noted, when re-adding the keyboard, that there was no bare "dvorak" layout anymore. I had to select "English (Dvorak)", with the flag of the United States. I don't think this layout previously existed? Previously, the switcher widget did not show a flag for Dvorak, instead showing the letters "dvk" or "dvorak".

I think what probably happened here is that this bare "dvorak" layout was removed in 5.27.6 in favor of localized Dvorak layouts with a flag, but this broke existing configurations because the layout name defined in the system configuration no longer exists.

If this is the case, IMO this should be fixed with a point release so that users who have the existing configuration are seamlessly upgraded to the new configuration for Dvorak layouts. Basically, fixing this issue as early as possible would be ideal so that this bites as few users as possible. I haven't used Qwerty in over a decade (it's only there for other people borrowing this computer), so this bug effectively made my computer unusable for me until I found the workaround.

SOFTWARE/OS VERSIONS
Operating System: Arch Linux 
KDE Plasma Version: 5.27.6
KDE Frameworks Version: 5.107.0
Qt Version: 5.15.10
Kernel Version: 6.3.9-arch1-1 (64-bit)
Graphics Platform: X11

ADDITIONAL INFORMATION

Apologies for putting this in kde/general. I wasn't able to determine which system component is responsible for managing keyboard configurations. As far as I know, the systemsettings KCM is just an interface, and Kwin probably handles the keyboard mapping itself, but I wasn't able to guess further than that.

Hopefully someone can help me by triaging. Thanks!