[tools] Initial support for nix shell/develop

flake.nix

@@ -0,0 +1,81 @@
+{
+  description = "Magic development environment";
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs?ref=nixos-unstable";
+    flake-compat = {
+      url = "github:edolstra/flake-compat";
+      flake = false;
+    };
+  };
+
+  outputs = { self, nixpkgs, flake-utils, flake-compat }:
+    let
+      linuxPkgs = nixpkgs.legacyPackages."x86_64-linux";
+      darwinPkgs = nixpkgs.legacyPackages."aarch64-darwin";
+      forAllSystems = function:
+        nixpkgs.lib.genAttrs [
+          "x86_64-linux"
+          "aarch64-darwin"
+        ] (system: function nixpkgs.legacyPackages.${system});
+      version = "0.3.0";
+      getBinary = system: {
+          "x86_64-linux" = "magic-x86_64-unknown-linux-musl";
+          "aarch64-darwin" = "magic-aarch64-apple-darwin";
+      }.${system} or (throw "unsupported system: ${system}");
+      fetchMagic = pkgs: binary: pkgs.stdenv.mkDerivation rec {
+          name = "magic";
+          src = pkgs.fetchurl {
+            url = "https://dl.modular.com/public/magic/raw/versions/${version}/${binary}";
+            sha256 = "sha256-wNweaK1TPqsVv9D1x7/m5kr1tryWfftzKCKDNdVBkOc=";
+          };
+
+          dontUnpack = true;
+
+          postInstall = ''
+            mkdir -p $out/bin
+            cp $src $out/bin/magic
+            chmod +x $out/bin/magic
+          '';
+        };
+      magicEnv = pkgs: magic: (pkgs.buildFHSEnv {
+        name = "magic-shell";
+        targetPkgs = pkgs: (with pkgs; [
+          libz
+          clang
+          lit
+          llvm
+          # Magic provides currently ncurses 6.5 on it's own but libtinfo is
+          # needed and in nixpkgs this does not seem to be provided separately
+          # https://github.com/NixOS/nixpkgs/issues/89769
+          ncurses
+        ]);
+        profile = ''
+          MODULAR_HOME=$HOME/.modular
+          BIN_DIR=$MODULAR_HOME/bin
+          MAGIC=$BIN_DIR/magic
+
+          if [ ! -e $MAGIC ]; then
+            mkdir -p $BIN_DIR
+            cp ${magic}/bin/magic $BIN_DIR/magic
+            echo 37e8aeee-7585-494b-83e4-59244188c2fe > "$MODULAR_HOME/webUserId"
+          fi
+
+          export PATH=$BIN_DIR:$PATH
+          # Seems to work but prints error 'complete: command not found' when 
+          # the shell is entered.
+          # Maybe related to https://github.com/NixOS/nix/issues/6091#issuecomment-1038247010
+          eval "$(magic completion --shell bash)"
+        '';
+        runScript = ''
+          magic shell
+        '';
+      }).env;
+    in
+    {
+      devShells = forAllSystems (pkgs: {
+        default = magicEnv pkgs (fetchMagic pkgs (getBinary pkgs.system));
+      });
+    };
+}
+

shell.nix

@@ -0,0 +1,13 @@
+# To support non-flake-enabled nix instances.
+(import
+  (
+    let lock = builtins.fromJSON (builtins.readFile ./flake.lock); in
+    fetchTarball {
+      url = lock.nodes.flake-compat.locked.url or
+      "https://github.com/edolstra/flake-compat/archive/${lock.nodes.flake-compat.locked.rev}.tar.gz";
+      sha256 = lock.nodes.flake-compat.locked.narHash;
+    }
+  )
+  { src = ./.; }
+).shellNix
+