Update nix dev env, add CI jobs to facilitate maintenance

.github/workflows/nix-dev-env.yml

@@ -0,0 +1,38 @@
+name: Nix developer enviroment
+on:
+  workflow_dispatch:
+  schedule:
+    - cron: '0 0 * * 0' # runs weekly on Sunday at 00:00
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  # Opens a PR with an updated flake.lock file
+  update_flake_lock:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: cachix/install-nix-action@v30
+      - uses: actions/checkout@v4
+      - uses: DeterminateSystems/update-flake-lock@main
+        with:
+          pr-title: "Update flake.lock"
+          pr-labels: |
+            L-ignore
+            A-dependencies
+
+  nix-dev-env:
+    strategy:
+      matrix:
+        runs-on: [ ubuntu-latest, macos-latest ]
+    runs-on: ${{ matrix.runs-on }}
+    steps:
+      - uses: cachix/install-nix-action@v30
+      - uses: actions/checkout@v4
+
+      - name: Activate nix env
+        run: nix develop -c echo Ok
+
+      - name: Check that we can compile all crates
+        run: nix develop -c cargo check --all-targets

flake.nix

@@ -8,21 +8,14 @@
         nixpkgs.follows = "nixpkgs";
       };
     };
-    solc = {
-      url = "github:hellwolf/solc.nix";
-      inputs = {
-        nixpkgs.follows = "nixpkgs";
-        flake-utils.follows = "flake-utils";
-      };
-    };
   };
 
-  outputs = { self, nixpkgs, rust-overlay, flake-utils, solc }:
+  outputs = { self, nixpkgs, rust-overlay, flake-utils }:
     flake-utils.lib.eachDefaultSystem (system:
       let
         pkgs = import nixpkgs {
           inherit system;
-          overlays = [ rust-overlay.overlays.default solc.overlay ];
+          overlays = [ rust-overlay.overlays.default ];
         };
         lib = pkgs.lib;
         toolchain = pkgs.rust-bin.stable.latest.default.override {
@@ -33,9 +26,14 @@
         devShells.default = pkgs.mkShell {
           nativeBuildInputs = with pkgs; [
             pkg-config
-            solc_0_8_23
-            (solc.mkDefault pkgs solc_0_8_23)
             toolchain
+            rust-jemalloc-sys
+            cargo-nextest
+
+            # test dependencies
+            solc
+            vyper
+            nodejs
           ];
           buildInputs = lib.optionals pkgs.stdenv.isDarwin [
             pkgs.darwin.apple_sdk.frameworks.AppKit