SDDM can't start Plasma

void1984 · n00b Joined: 22 Jul 2016 Posts: 5

Hi

I've upgraded from KDE4 to KDE5 aka Plasma.
I can start Plasma using `startx` command just fine.
Unfortunately I can start it via sddm. It crashes with a message:

asturm · Developer Joined: 05 Apr 2007 Posts: 8935

emerge --info

Sakarias · n00b Joined: 12 May 2007 Posts: 60

void1984 · n00b Joined: 22 Jul 2016 Posts: 5

void1984 · n00b Joined: 22 Jul 2016 Posts: 5

The only place that I have egl set is mesa package:
media-libs/mesa egl wayland

void1984 · n00b Joined: 22 Jul 2016 Posts: 5

Fitzcarraldo · Posted: Sat Jul 23, 2016 10:48 am Post subject:

If you're not fixed on using SDDM specifically, you could see if your installation will work with LightDM instead. I could not get SDDM to work with nvidia-drivers in Gentoo Stable, but I managed to get LightDM working with nvidia-drivers by doing the following:

1. Merge x11-misc/lightdm.
2. Re-merge kde-plasma/plasma-meta with USE="-sddm".
3. Remove the x11-misc/sddm package and kde-plasma/sddm-kcm package with "emerge --ask --depclean".
4. Edit the file /etc/lightdm/lightdm.conf to add the line "greeter-session=lightdm-kde-greeter" as specified in Gentoo Wiki article LightDM.
5. Edit the file /etc/lightdm/lightdm.conf to add the line "display-setup-script=/etc/X11/Sessions/plasma".
6. Create the above-mentioned Bash script /etc/X11/Sessions/plasma containing the following:

void1984 · n00b Joined: 22 Jul 2016 Posts: 5

Thank you so much!
That was the solution.
It's worth nothing, for other potential readers, that lightdm pulls and uses gtk greeter by default.

I don't care about sddm, I've never used it before. I used kdm, but with Plasma it's gone.
Everything seems to works perfectly.

Somehow the Plasma session is listed twice on the list of possible environments.

Fitzcarraldo · Posted: Sun Jul 24, 2016 12:38 pm Post subject:

Glad to know you now have a working DM.

christian_burger · n00b Joined: 14 May 2003 Posts: 13

1. THIS is the issue: the fact that Kwin won't start and throws this message: "Plasma is unable to start as it could not correctly use OpenGL 2."

2. That has NOTHING to do with sddm or whatever other "script" you're using to start Plasma5.

3. It has to do with the fact that Plasma 5 won't start if you're using the NVidia proprietary drivers / libraries.
There is a workaround for this problem which is pretty crippling to your system:
eselect opengl set xorg-x11
eselect opencl set mesa

4. The issue was not resolved and is still happening as of 2017-01-28, so this should obviously be submitted to Plasma 5 / KDE developers.
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Christian Burger

grooveman · Veteran Joined: 24 Feb 2003 Posts: 1217

christian_burger · n00b Joined: 14 May 2003 Posts: 13

asturm · Developer Joined: 05 Apr 2007 Posts: 8935

It is a bit puzzling what's going on with your Nvidia settings, since we clearly have users in IRC that are using Plasma-5 (and of course starting with sddm) just fine, using the binary blob.

It is also a bit sad that no one of the people who were able to solve their issue with nvidia-drivers have made it to the Gentoo KDE Wiki troubleshooting section yet.

Fitzcarraldo · Posted: Thu Feb 02, 2017 11:14 pm Post subject:

I have been using nvidia-drivers with Plasma 5 since July last year, including working rendering and compositing (System Settings has 'Rendering backend: OpenGL 2.0'). However, I was never able to get SDDM working (despite faithfully following the instructions in the Gentoo Wiki) so I switched to using LightDM instead of SDDM, which works fine.

Atmmac · Posted: Fri Feb 03, 2017 7:11 pm Post subject:

Interesting I have SDDM working with plasma 5. The arch wiki actually has some information that you need to follow specifically for optimus cards.

Fitzcarraldo · Posted: Fri Feb 03, 2017 10:32 pm Post subject:

christian_burger · n00b Joined: 14 May 2003 Posts: 13

asturm · Developer Joined: 05 Apr 2007 Posts: 8935

the.root · Posted: Tue Feb 07, 2017 4:42 am Post subject:

I had this same issue with Plasma on a new build, first time I have seen it. After fooling around for a while I finally found the cause (embarrassingly) : I forgot to add my actual login user account to the "video" group.
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Ps = (1.5 x 6 x .75) / {(4/3) (pi) [(31.039 x 10^15) (46.5 x 10^9)]^3}
Seems like a waste..

milesrout · n00b Joined: 10 Feb 2017 Posts: 1 Location: Middle Earth

My user account is in the video group and I get the same issue, so that can't be the only cause.

Barthoz · n00b Joined: 14 Feb 2017 Posts: 1

The egl flag fixed this problem for me.

jasn · Guru Joined: 05 May 2005 Posts: 439 Location: Maryland, US

FWIW, I have an nvidia (nvidia-drivers) system where as root I could start the KDE/Plasma DE, but as my user I could not. I received the "Plasma is unable to start as it could not correctly use OpenGL 2." popup message when I tried. Thinking it was a permission issue, I added my user account to the video group and tried again, but received the same message. So using Barthoz's suggestion I added egl to my global use flags, and a world update re-emerged the following;

dev-qt/qtgui-4.8.7
dev-qt/qtopengl-4.8.7
kde-frameworks/plasma-5.31.0
kde-plasma/kinfocenter-5.9.2

After logging back out and back in, my user account can now bring up the KDE/Plasma desktop without issue.

[Update]

After reading this thread, and then this bug report I removed both the egl and gles2 USE flags, and then re-emerged all qt, kde, and plasma components, and my user account can startup the KDE/Plasma DE without issue.

Thanks..

the.root · Posted: Thu Feb 16, 2017 8:26 pm Post subject:

jasn - is sddm in the video group as well? When I try to start sddm without it in the video group all I get is a black screen.

FWIW, I don't have the 'egl' or 'gles2' useflag set on either my laptop or desktop which are plasma/sddm/nvidia builds, so it's definitely not a requirement for my builds. Before I checked to see if my user and sddm were both in the video group I tried adding those individually and uDN world, but it didn't resolve.
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Ps = (1.5 x 6 x .75) / {(4/3) (pi) [(31.039 x 10^15) (46.5 x 10^9)]^3}
Seems like a waste..

jasn · Guru Joined: 05 May 2005 Posts: 439 Location: Maryland, US

clytle374 · Apprentice Joined: 01 Aug 2006 Posts: 221

This issue has been plaguing me forever now. I had another pair of issues come up in march that made a real mess of things. First off I had some lib issue that required my pulling the 2nd nvidia card out, it's a Lenovo y510p. So it's a optimus laptop with dual nvidia cards on top of that.

I was so deep in a work project I couldn't risk breaking the machine. I had found this last fall and ended up deciding that the nvidia card failed. I had problems getting the lighdm to work, just got lighdm working and that doesn't help. elg use doesn't help, trying the gles2 now.

At this point I've tried so many things that I have no idea where to start. I seem to get keep rotating through black screens and can't open opengl error.
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NooB since RedHat 6.1