dual monitor config problem in Plasma 5 [SOLVED]

JohnN

After updating to Plasma 5, my extended dual monitor configuration that I have used for years worked through several reboots and now suddenly doesn't. The desktop is being mirrored to both monitors. Other user accounts are working fine. Only one monitor shows up in System Settings, and I see no way to adjust this. I have tried restarting with a new, empty profile, but the settings are still being saved somewhere I cannot find. (I disabled the .config, .local and .kde4 directories and got the same result.) How can I fix this?

John

JohnN · Posted: Sun Aug 21, 2016 6:31 am Post subject:

So, no help here at Gentoo, but I found the still-unresolved but work-around-able bug on the KDE forums.

I logged out of X, deleted the file in .local/share/kscreen, logged in again, configured my screens, and made the .local/share/kscreen file read-only.

This bug has been around in kscreen 2 for quite a while now, it seems, with no real solution in sight.

https://bugs.kde.org/show_bug.cgi?id=346961

radio_flyer · Posted: Sun Aug 21, 2016 3:18 pm Post subject:

Yes, welcome to the world of plasma 5 multi-monitor support.

That kscreen fix works fine for a while, until it doesn't. The panel also likes to dance around among the monitors on my system; I can usually fix that (for a few logins) by editing .config/plasma-org.kde.plasma.desktop-appletsrc and in the org.kde.panel 'containment' resetting the lastScreen value back to its correct value and logging out and back in.

KDE5 / Plasma 5 multi-screen support on Gentoo is unlikely to get any better until qtcore-5.6.2 or 5.7.1 hits portage. See comment 63 in that KDE bug report.

JohnN · Posted: Wed Aug 24, 2016 4:40 pm Post subject:

Thanks for reply. Yes, I see that now. I frequently get a black screen with no functioning desktop settings on the right monitor, and I have to delete the kscreen file and reset permissions on the directory.

I am so disappointed in Gentoo for pushing me to finally migrate to Plasma 5 with warnings about no upstream support, security holes, etc. I would love to go back to the KDE4 configuration that has given me years of stable, productive work with no X headaches, but I'm afraid of breaking my system trying to roll back. I like many of the new features in Plasma 5 and some things work better than before, but it has the feel of a half-completed project.