nix dev env maintenance

I would like to use the dev env provided by nix to build foundry but
it's quite outdated. This PR makes it up to date and automated some of
the maintenance.

Use solc from nixpkgs instead of custom flake. This will at least update
solc when it's updated in nixpkgs versus remaining on the same version
until someone manually edits flake.nix and makes a PR.

Add a CI job to ensure the nix dev env can be used to build foundry. I
would like to make it possible to run all the tests too but this would
requires more work to track down reasons for the invididual test
failures.

Author: sveitser

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

@@ -0,0 +1,47 @@
+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-linux:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: cachix/install-nix-action@v30
+      - uses: actions/checkout@v4
+
+      - name: Activate nix env
+        run: nix develop --accept-flake-config -c echo Ok
+
+      - name: Check that we can compile all crates
+        run: nix develop --accept-flake-config -c cargo check --all-targets
+
+  nix-env-macos-arm:
+    runs-on: macos-latest
+    steps:
+      - uses: cachix/install-nix-action@v30
+      - uses: actions/checkout@v4
+
+      - name: Activate nix env
+        run: nix develop --accept-flake-config -c echo Ok
+
+      - name: Check that we can compile all crates
+        run: nix develop --accept-flake-config -c cargo check --all-targets

flake.lock

@@ -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