Setting up hardware acceleration for a VNC server

Here is what I do :
Open Termux
virgl_test_server_android --angle-gl
Open another Termux instance
proot-distro login debian --user void --shared-tmp --isolated
vncserver -xstartup "/usr/bin/xterm" -once -cleanstale -localhost no
Go in this VNC server which has no desktop environment
export MESA_GL_VERSION_OVERRIDE=4.6COMPAT GALLIUM_DRIVER=virpipe DISPLAY=:1
glmark2

That last command fails