[Mesa-dev] Can't get self-built Mesa to work on the Raspberry Pi 4

[lists at luckyxxl.de]

Hi all,

In order to check whether a OpenGL ES driver bug I'm hitting on the 
Raspberry Pi 4 still appears in the latest Mesa version, I'm trying to 
build Mesa myself and run my application with that. Unfortunately I'm 
having no success with either 19.3.2 (the version distributed with 
raspbian), 20.3.2 (the latest release) or the current master. Each time 
the driver initialization fails with the following messages printed to 
the console:

libGL error: failed to create dri screen
libGL error: failed to load driver: vc4

This is my meson setup command line:

~/Downloads/meson-0.56.0/meson.py setup -Ddri-drivers= 
-Dgallium-drivers=v3d,vc4 -Dvulkan-drivers= -Dplatforms=x11 
-Dbuildtype=debug -Dbackend=ninja -Dprefix=/home/pi/mesa-build build

(vc4 seems to be required in the gallium-drivers option, otherwise it 
failed with 'libGL error: MESA-LOADER: failed to open vc4 [...]'. I 
guess this makes sense given the dependency on vc4 as explained here 
https://docs.mesa3d.org/drivers/v3d.html ?)

I'm having this issue using both SDL or freeglut and either starting the 
app from ssh (using 'export DISPLAY=:0') or directly on the desktop.

I'm a total beginner when it comes to Mesa and the pi graphics driver 
stack, so any help would be highly appreciated :) Thanks!

Lukas