I was running Mageia on a hard disk.  That hard disk crashed.  I had downloaded the new Chimaera 4.0.  Loaded that on another hard disk.  That crashed.  I am running in crippled mode.  A trip to the hospital put all on hold.  But I have a new Crucial 1 TB SSD coming.  If it stores data, it eventually dies.  I have a monstrous big case with 10 5 1/4" bays and I use carts so, I will be transitioning away from hard disks.  Get used to SSDs dying suddenly.  That is the way of the SSD tribe.  Running OSs from a SSD is hard on SSDs.  Since a 500 GB Crucial SSD with a 5 year warranty is only $60, I will do that.  I will put /home et al on the 1 TB, and set up another 500 TB SSD for timeshift and saving daily driver VM images. All SSDs are ephemeral and you have to expect that and work with the problem. When your OS boot SSD eventually starts dying, replace it with a new cheap but quality SSD and copy backups over, update GRUB and continue on.

In the bad old days of 80 GB hard drives, I used to have problems from time to time, but usually got a lot more out of a hard disk with fsck -c- -c -y, a deep bad block check that did wonders.  But that was an all night affair.  It will take 2 weeks or more to do a 2 TB hard disk that way.

Life is hard and you better have good backups.

Apt-get reinstall task-kde-desktop ran but nothing has changed.  So it looks like a reinstall may be the best way out.  #@##!!!

Tried an apt-get upgrade sddm.  Still nada.
Afraid to try upgrade silm.

Nope.  I did this and it hosed my system.  I can no longer as a user startx at all.  I can log in as root and start xfce.  But the browsers I was using there are no longer working.  I had to load FireFox.  And still no way that I know of the start KDE.  This was not a good answer.  When I try to log in and startx as a user, I now get a waiting for x server to shut down message and then a cannot connect to x server error message.

Thanks for the clues.  Ny daily driver hard disk seemed to have cratered.  It was an old install anyway. I had just partitioned two new hard disks, and I have been backing up home to 2 ssds.  So I have saved /homes up to date in spades.

It looks like I may have to do the right thing and set up a fstab entry for my /home on this hard disk I am booting from.  And set my users to make sure it boots from that.

Next to do is purge Devuan of the /home it has in my Devuan partition and make it stop trying to mount it at all.  I was hoping the installer would be more straight forward in allowing setting the proper home directory to use.  Should perhaps that ,ight be a propoer bug report? Just before the crash, I was trying to understand udev rules.

And now back to fighting setting up Plasma and browsers and getting synaptic working.  Amazingly, to install VLC it wants to rip out my newly installed Vivaldi browser.  I need a beer.

I have been using Mageia 5.0 up to date.  I installed Pepper Flash and it has worked well using older versions of Opera and Firefox. Pepper Flash is a Google product and is non-free.