A very inmature exploration of #38

flake.nix

@@ -7,22 +7,30 @@
       nixos.url = "nixpkgs/release-20.09";
       home.url = "github:nix-community/home-manager/release-20.09";
       flake-utils.url = "github:numtide/flake-utils";
+
+      # DevShells
+      # Use the nixpkgs master for access to latest tooling.
+      devshell.url = "github:numtide/devshell/master";
+      devshell.inputs.nixpkgs.follows = "master"; # TODO: How does this compare with pkgImport below?
+      naersk.url = "github:nmattia/naersk";
+      naersk.inputs.nixpkgs.follows = "master";
+      mozilla-overlay = { url = "github:mozilla/mozilla-nixpkgs"; flake = false; };
     };
 
-  outputs = inputs@{ self, home, nixos, master, flake-utils, nur }:
+  outputs = inputs@{ self, home, nixos, master, flake-utils, nur , devshell, naersk, mozilla-overlay }:
     let
       inherit (builtins) attrNames attrValues readDir elem;
       inherit (flake-utils.lib) eachDefaultSystem;
       inherit (nixos) lib;
       inherit (lib) all removeSuffix recursiveUpdate genAttrs filterAttrs;
       inherit (utils) pathsToImportedAttrs genPkgset overlayPaths modules
-        genPackages pkgImport;
+        genPackages pkgImport devShellModules;
 
       utils = import ./lib/utils.nix { inherit lib; };
 
       system = "x86_64-linux";
 
-      externOverlays = [ nur.overlay ];
+      externOverlays = [ nur.overlay (import mozilla-overlay) devshell.overlay naersk.overlay];
       externModules = [ home.nixosModules.home-manager ];
 
       pkgset =
@@ -43,6 +51,8 @@
 
         nixosModules = modules;
 
+        devShellModules = devShellModules;
+
         templates.flk.path = ./.;
 
         templates.flk.description = "flk template";

lib/utils.nix

@@ -82,6 +82,13 @@ in
       (recursiveUpdate cachixAttrs modulesAttrs)
       profilesAttrs;
 
+  devShellModules =
+    let
+      # shells
+      shellList = import ../shells/list.nix;
+    in
+    pathsToImportedAttrs moduleList;
+
   genPackages = { overlay, overlays, pkgs }:
     let
       packages = overlay pkgs pkgs;

shells/list.nix

@@ -0,0 +1,3 @@
+[
+  ./rust
+]

shells/rust/default.nix

@@ -0,0 +1,27 @@
+with pkgs;
+
+mkDevShell {
+  name = "Personal Rust DevShell";
+
+  packages = [
+    latest.rustChannels.stable.rust
+    wasm-bindgen-cli
+    binaryen
+
+    ncurses
+    pkgconfig
+    openssl
+    openssl.dev
+  ];
+
+  env.RUST_BACKTRACE = "1";
+
+  commands = [
+    {
+      name = "hello";
+      help = "say hello";
+      category = "fun";
+      command = "echo '''hello''' ";
+    }
+  ];
+}