`language.c.includes` collision when trying to use libX11 and xorgproto

[duckpuppy]

Describe the bug

xorg.libX11 and xorg.xorgproto both contain some of the same files, but both are often needed when working with X11 libs. Including both of them in language.c.includes causes a collision.

To Reproduce

Steps to reproduce the behavior:

1. Initialize a devshell flake.nix
2. Create a devshell.toml file with:

   imports = [ "language/c" ]
   [language.c]
   compiler = "pkgs.gcc-unwrapped"
   includes = [ "xorg.libX11", "xorg.xorgproto" ]

Expected behavior

Include files from both packages are on the include path

System information

WSL2 / Debian Bullseye

Additional context

I'm trying to work on a golang project that uses SDL2 (and as such needs the C compiler as well), and SDL2 requires both libX11 and xorgproto.

flake.nix:

{
  description = "virtual environments";

  inputs.devshell.url = "github:numtide/devshell";
  inputs.flake-utils.url = "github:numtide/flake-utils";

  outputs = { self, flake-utils, devshell, nixpkgs }:
    flake-utils.lib.eachDefaultSystem (system: {
      devShell =
        let pkgs = import nixpkgs {
          inherit system;

          overlays = [ devshell.overlay ];
        };
        in
        pkgs.devshell.mkShell {
          imports = [ (pkgs.devshell.importTOML ./devshell.toml) ];
        };
    });
}

devshell.toml:

# https://numtide.github.io/devshell
imports = [
  "language/c"
]

[language.c]
compiler = "pkgs.gcc-unwrapped"
includes = [
  "SDL2", 
  "xorg.libX11",
  "xorg.xorgproto"
]

[[commands]]
package = "devshell.cli"
help = "Per project developer environments"

[[commands]]
package = "go"
help = "Golang language compiler"

[devshell]
packages = [
  "delve",
  "golangci-lint",
  "gopls",
  "gomodifytags",
  "pkg-config"
]

The above configuration gives the following error:

error: builder for '/nix/store/fv8qvjd82wmrm1s0qb6ca3w5d6q9z2ab-devshell-dir.drv' failed with exit code 25;
       last 1 log lines:
       > error: collision between `/nix/store/2dspcvr8zwwcl35pilbsgqhnid3kfh68-xorgproto-2021.5/include/X11/extensions/XKBgeom.h' and `/nix/store/sgw0sxwx46hqwlcm3d834f10p1qx7c5y-libX11-1.8.1-dev/include/X11/extensions/XKBgeom.h'
       For full logs, run 'nix log /nix/store/fv8qvjd82wmrm1s0qb6ca3w5d6q9z2ab-devshell-dir.drv'.
error: 1 dependencies of derivation '/nix/store/2cb7rrqfrx2ry2aw1qi4cx3kbpkbi2sa-devshell-env.drv' failed to build