Nixpkgs: glvnd/libGL stubs/mesa missing GLES3/gl3ext.h

[lheckemann]

Describe the bug
gl3ext.h isn't in any of libglvnd.dev, libGL.dev, or mesa.dev. I'm not sure exactly where it should be, but it should probably be available _somewhere_. This causes superTuxKart to fail to build on aarch64.

To Reproduce
Steps to reproduce the behavior:

1. nix-build channel:nixos-unstable -A superTuxKart

Expected behavior
Working cached build

Metadata

• system: "aarch64-linux"
• host os: Linux 5.6.5, NixOS, 20.09pre222244.22a3bf9fb9e (Nightingale)
• multi-user?: yes
• sandbox: yes
• version: nix-env (Nix) 2.3.4
• channels(root): "nixos-20.03.1445.95b9c99f6d0" (note: not using this)
• nixpkgs: /nix/var/nix/profiles/per-user/root/channels/nixos

Maintainer information:

# a list of nixpkgs attributes affected by the problem
attribute:
 - superTuxKart 
 - libglvnd
 - libGL
 - mesa
# a list of nixos modules affected by the problem
module:

[eadwu]

It isn't built on our configuration since we enable glvnd on Linux [1] for mesa. It appears in libglvnd 1.3.1 though and it looks like our version is outdated [2].

[1] https://gitlab.freedesktop.org/mesa/mesa/-/blob/master/include/meson.build#L25
[2] https://github.com/NVIDIA/libglvnd/search?q=gl3ext&type=Commits

[lheckemann]

Good catch! I'll open a bump PR. Thanks!

[Emantor]

Closing this since the bump has been merged.