Move away from numtide

Get rid of the numtide shell, as it doesn't have any good support for
shellHook. Also, directly create the pre-commit check so that we can
leverage its resulting bits in the packages.

We now will have acces to things like pre-commit-config.yaml in the
folder structure

flake.nix

@@ -3,7 +3,6 @@
   description = "Greg's homepage";
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
-    devshell.url = "github:numtide/devshell";
     flake-parts.url = "github:hercules-ci/flake-parts";
     flake-root.url = "github:srid/flake-root";
     hooks.url = "github:cachix/git-hooks.nix";
@@ -13,15 +12,11 @@
   outputs =
     { flake-parts, ... }@inputs:
     flake-parts.lib.mkFlake { inherit inputs; } {
-      imports = [
-        inputs.devshell.flakeModule
-        inputs.flake-root.flakeModule
-        inputs.hooks.flakeModule
-      ];
+      imports = [ inputs.flake-root.flakeModule ];
       flake = {
         # Universal things
         # final: prev:
-        overlays.default = _: _: { };
+        overlays.default = _final: _prev: { };
       };
       systems = [
         "x86_64-linux"
@@ -29,7 +24,7 @@
         "aarch64-darwin"
       ];
       perSystem =
-        { pkgs, ... }@inputs':
+        { pkgs, self', ... }@inputs':
         let
           naersk-lib = pkgs.callPackage inputs.naersk { };
         in
@@ -38,11 +33,10 @@
             inherit (inputs') system;
             overlays = [ ];
           };
-          # https://numtide.github.io/devshell/intro.html
-          devshells.default = rec {
+          devShells.default = pkgs.mkShell rec {
             # These commands will be shown in the motd that users read
             # upon entering the shell
-            packages = with pkgs; [
+            inputsFrom = with pkgs; [
               expat
               fontconfig
               freetype
@@ -57,64 +51,46 @@
               libxkbcommon
             ];
 
-            env = [
-              {
-                name = "LD_LIBRARY_PATH";
-                value = builtins.foldl' (a: b: "${a}:${b}/lib") "${pkgs.vulkan-loader}/lib" packages;
-              }
-            ];
-            commands = [
-              {
-                package = pkgs.cargo;
-                category = "tools";
-                help = "Rust build and package tool";
-              }
-              {
-                package = pkgs.rustc;
-                category = "languages";
-                help = "Rust compiler";
-              }
-              {
-                package = pkgs.rustfmt;
-                category = "tools";
-                help = "Standard Rust formatting tool";
-              }
-              {
-                package = pkgs.clippy;
-                category = "tools";
-                help = "Rust linter";
-              }
-              {
-                package = pkgs.stdenv.cc;
-                category = "languages";
-                help = "C compiler to help with building native code";
-              }
-              {
-                package = pkgs.pre-commit;
-                category = "tools";
-                help = "Tool to help enforce commits make sense";
-              }
+            packages = with pkgs; [
+              cargo
+              clippy
+              pre-commit
+              rustc
+              rustfmt
+              stdenv.cc
             ];
+
+            buildInputs = self'.checks.pre-commit.enabledPackages;
+
+            shellHook =
+              let
+                lib_path = builtins.foldl' (a: b: "${a}:${b}/lib") "${pkgs.vulkan-loader}/lib" packages;
+              in
+              ''
+                export LD_LIBRARY_PATH="${lib_path}"
+              ''
+              + self'.checks.pre-commit.shellHook;
           };
 
-          pre-commit = {
-            check.enable = true;
-            settings.src = ./.;
-            settings.hooks = {
-              check-added-large-files.enable = true;
-              check-case-conflicts.enable = true;
-              check-merge-conflicts.enable = true;
-              check-symlinks.enable = true;
-              deadnix.enable = true;
-              end-of-file-fixer.enable = true;
-              fix-byte-order-marker.enable = true;
-              mixed-line-endings.enable = true;
-              nixfmt-rfc-style.enable = true;
-              trim-trailing-whitespace.enable = true;
-              # Rust hooks
-              cargo-check.enable = true;
-              clippy.enable = true;
-              rustfmt.enable = true;
+          checks = {
+            pre-commit = inputs.hooks.lib.${inputs'.system}.run {
+              src = ./.;
+              hooks = {
+                check-added-large-files.enable = true;
+                check-case-conflicts.enable = true;
+                check-merge-conflicts.enable = true;
+                check-symlinks.enable = true;
+                deadnix.enable = true;
+                end-of-file-fixer.enable = true;
+                fix-byte-order-marker.enable = true;
+                mixed-line-endings.enable = true;
+                nixfmt-rfc-style.enable = true;
+                trim-trailing-whitespace.enable = true;
+                # Rust hooks
+                cargo-check.enable = true;
+                clippy.enable = true;
+                rustfmt.enable = true;
+              };
             };
           };