Bug 711842 – OpenGL simply doesn't work.

• Product: Gentoo Linux
• Status: RESOLVED INVALID

[Description rnddim 2020-03-08 02:23:56 UTC]

For some reason, while updating my system, things that wish to grab an opengl context no longer are able to. (Applications that had grabbed a context before it all fell apart kept working.) For example, 'glxinfo' simply gives:

Error: couldn't find RGB GLX visual or fbconfig

While sddm (and other Qt-based applications) throw up

qglx_findConfig: Failed to finding matching FBConfig for QSurfaceFormat(version 2.0, options QFlags<QSurfaceFormat::FormatOption>(), depthBufferSize -1, redBufferSize 1, greenBufferSize 1, blueBufferSize 1, alphaBufferSize -1, stencilBufferSize -1, samples -1, swapBehavior QSurfaceFormat::SingleBuffer, swapInterval 1, colorSpace QSurfaceFormat::DefaultColorSpace, profile  QSurfaceFormat::NoProfile)

a number of times before falling back on some alternate solution or giving (sddm for example is an "OpenGL or bust" Qt program).

I've uploaded a file containing all the packages that have been emerged in that update (the only ones since my last fully successful boot, which btw proves the problem isn't the result of some previous system update). I restarted my computer in the middle of updating once I noticed this problem, in the hopes that a restart would make OpenGL work again, but now nothing OpenGL-related works.

X11 still works, (I'm typing right now in Firefox while running ctwm as a window manager), so I know it's _just_ OpenGL.

The only item in the update list I can see maybe causing issues is the linux-firmware update, but I have yet to find back the website that explains what firmware I need for my GPU, and if the needs have changed with the update.

I have an integrated Radeon 3100 card (RS780C) in my computer at the moment, as per 'lspci'.

Reproducible: Always

[Comment 1 rnddim 2020-03-08 02:24:37 UTC]

Created attachment 617438 [details]
Packages that could've possibly broken OpenGL

[Comment 2 Matt Turner 2020-03-08 04:52:46 UTC]

Did you emerge both media-libs/mesa and x11-base/xorg-server with USE=libglvnd?

[Comment 3 Matt Turner 2020-03-08 04:53:15 UTC]

Also, have you restarted X? This sounds like the same issue as https://bugs.gentoo.org/711776

[Comment 4 rnddim 2020-03-08 05:32:56 UTC]

I do have libglvnd installed because mesa and xorg-server have those new useflags on by default, but I have yet to install mesa or xorg-server with the new flag. I did notice something about that library in the update process, but I just assumed I'd always had it and just the use flag was new.

Even though no currently installed packages need libglvnd (if I were to complete the update process there would be), I would not be surprised if just having that library exist is causing problems. So either I need to update xorg & mesa to use libglvnd, or ensure that nothing wants it and then uninstall it. Since I've never had libglvnd before today, I'll try making it go away first.

To clarify, I only noticed the problem with trying to start new programs. Existing OpenGL-based programs, including Qt programs (in particular, I use a KDE-based desktop) were continuing to run just fine. And of course, restarting my computer means every program is being started new, so no OpenGL-based applications work.

(BTW, it's worth noting that certain Qt programs are able to fallback on some non-OpenGL based solution for drawing itself, while others require OpenGL to function.)

Also, I wrote a very quick C++ program to try and probe OpenGL a bit, and glXGetFBConfigs() gives back 0 framebuffer configurations. In case that helps any.

As for the linked bug, the only time I couldn't start an X server was when I had accidentally left the one that failed to start sddm (a Qt-based program) running.

[Comment 5 Matt Turner 2020-03-08 05:41:40 UTC]

Yeah, if libglvnd is installed and you haven't enabled USE=libglvnd for mesa and xorg-server, everything is going to be broken.

Finish the update and restart X :)