"Unable to open a display" error on linux

I tried to build blender 2.8 from source on my Linux debian 10, and when i try to launch it in the console it shows this error:
“Unable to open a display
Can anyone help me ?

  • Verify if the build from blender.org has the same problem.
  • Paste the complete terminal output if there is more, and run with --debug.
  • Try running Blender in gdb to find exactly where it crashes.

In a terminal window where Blender will not start, do echo $DISPLAY to see if you have DISPLAY set.

Also, it looks as if you are running as root. You might try running Blender as a regular user.

The echo $DISPLAY give no output

Launching blender as a regular user works, but it does exactly the same thing as the official build : it runs at 2fps in the viewport without doing anything more than just rotate the camera.

The DISPLAY environment variable is used to tell the X server where to open windows. It needs to be set to run GUI applications. The default value is usually :0.0 . Even if you set it for the root user, you may run into authorization issues trying to open a window on another user’s display.

Regarding slow viewport performance, that sounds like a hardware/video driver issue.

The slow viewport is due to hardware issue, my pc isn’t a Monster of power, but it wasn’t THAT slow with blender 2.79. I read on the internet that blender 2.80 actually has issues with opengl support. I think it might be the issue here.