OneAngstrom ans ubuntu 26.04.1 LTS

marc 2

I tried to install OneAngstrom on Ubuntu 26.04.1. I seems to have issue about X11 render and OPENGL version. the only way to launch OneAngstrom was with this command : __GLX_VENDOR_LIBRARY_NAME=mesa LIBGL_ALWAYS_SOFTWARE=1 QT_QPA_PLATFORM=xcb SAMSON-Core.sh

I give you the full configuration and crash :
SAMSON 2026 R1 crashes on Ubuntu 26.04 (Wayland only, NVIDIA): "QOpenGLWidget: Failed to make context current"

Hello,

SAMSON 2026 R1 (11.0.1) crashes shortly after startup on a workstation running Ubuntu 26.04 LTS. Only Mesa software rendering lets it start.

Configuration

OS: Ubuntu 26.04 LTS, GNOME 50, Wayland session (this release no longer offers a GNOME Xorg session, X11 apps run through XWayland)
GPU: NVIDIA GeForce GTX 1080 (8 GB)
Driver: NVIDIA 580.178.04, OpenGL 4.6
Installed packages: libxcb-cursor0, libatomic1, libxcb-xinerama0, libopengl0, libglx0

OpenGL works through XWayland on the same display: glxinfo -B reports direct rendering, the GTX 1080 as renderer and an OpenGL 4.6 core profile.

Symptom
SAMSON reaches the end of its startup, then the OpenGL widgets fail and the application segfaults:

$ QT_DEBUG_PLUGINS=1 QT_QPA_PLATFORM=xcb ~/OneAngstrom/SAMSON-Application/11.0.1/Binaries/SAMSON-Core.sh
...
QOpenGLWidget: Failed to make context current
QOpenGLWidget: Failed to make context current
Timing # 8.1801s   [SAMSON start duration] main:958
qt.core.plugin.factoryloader: checking directory path "~/OneAngstrom/SAMSON-Application/11.0.1/Binaries/accessiblebridge" ...
QOpenGLWidget: Failed to make context current
QOpenGLWidget: Failed to make context current
QOpenGLWidget: Failed to make context current
Segmentation fault (core dumped)

What I tried

QT_QPA_PLATFORM=xcb: crash (log above)
QT_QPA_PLATFORM=wayland: does not work
QT_QPA_PLATFORM=xcb QT_XCB_GL_INTEGRATION=xcb_egl: does not work
Both of the above with QTWEBENGINE_CHROMIUM_FLAGS="--disable-gpu": does not work
__GLX_VENDOR_LIBRARY_NAME=mesa LIBGL_ALWAYS_SOFTWARE=1 QT_QPA_PLATFORM=xcb: SAMSON starts (software rendering)

The issue therefore seems to come from the creation of the OpenGL context with the NVIDIA driver through XWayland, while other OpenGL clients work on the same display.

Questions

Is this a known issue with Ubuntu 26.04 and Wayland-only sessions?
Is there a setting or environment variable to change how SAMSON creates its OpenGL context, or is a fix planned?

DmitriyMarin

Dear @marc-2 ,

Thank you very much for reporting the issue and such a detailed description! And sorry about this issue.
Yes, there are some reported issues for SAMSON on Ubuntu 26.04 and Wayland.
We will try to fix this for the next major SAMSON release, since it involves OpenGL rendering failures in the core of SAMSON.