GL setup failure on non-NixOS linuxen

[deepfire]

Basically, it's an instance of NixOS/nixpkgs#9415, and manifests like this:

[nix-shell:~/src/reflex-glfw]$ cabal clean
cleaning...

[nix-shell:~/src/reflex-glfw]$ cabal build
Package has never been configured. Configuring with default flags. If this
fails, please run configure manually.
Warning: The package list for 'hackage.haskell.org' does not exist. Run 'cabal
update' to download it.
Resolving dependencies...
Configuring reflex-glfw-0.1.0.0...
Building reflex-glfw-0.1.0.0...
Preprocessing library reflex-glfw-0.1.0.0...
[1 of 1] Compiling Reflex.GLFW      ( src/Reflex/GLFW.hs, dist/build/Reflex/GLFW.o )
Preprocessing executable 'reflex-glfw-demo' for reflex-glfw-0.1.0.0...
[1 of 2] Compiling Gear             ( Gear.hs, dist/build/reflex-glfw-demo/reflex-glfw-demo-tmp/Gear.o )
[2 of 2] Compiling Main             ( Demo.hs, dist/build/reflex-glfw-demo/reflex-glfw-demo-tmp/Main.o )
Linking dist/build/reflex-glfw-demo/reflex-glfw-demo ...

[nix-shell:~/src/reflex-glfw]$ dist/build/reflex-glfw-demo/reflex-glfw-demo
libGL error: unable to load driver: swrast_dri.so
libGL error: failed to load driver: swrast

[deepfire]

A nVidia-only solution is available in the form of the nix-install-vendor-gl.sh script.

[deepfire]

A Hackage release of reflex will allow reflex-glfw to be used without Nix, making the problem non-critical.

Given that, and that there is a promising solution (already working for nVidia GPUs), I'm dropping the issue from the Hackage release milestone.

[deepfire]

nix-install-vendor-gl.sh now lives in a separate repository: https://github.com/deepfire/nix-install-vendor-gl