Only compiled to be used with Panfrost and Lima driver (for ARM GPUs), other GPU can be present

update 20191004. libglvnd package now contains missing (pkgconfig) .pc files (gles2.pc (absant in official ALARM  too), gl.pc and egl.pc). So remove it from here now to avoid conflict. Their missing doesn't allow to compile some applications

If meson complain with one of the following error:
 ERROR: Build directory has been generated with Meson version 0.51.2, which is incompatible with current version 0.52.0.
* Means that meson has been updated between two compilations.
ninja: error: '/usr/lib/libLLVM-8.so', needed by 'src/gallium/targets/dri/libgallium_dri.so', missing and no known rule to make it
* Means that llvm has been updated between two compilations.

Then you need to remove build directory and restart a full build:
 rm -R src/build
 makepkg

On my computer it take about ten minutes for the full build, with MAKEFLAGS="-j4" in /etc/makepkg.conf config file (use 4 cores)