Update to Nix 2.22

Flake lock file updates:

• Updated input 'nix':
    'github:NixOS/nix/60824fa97c588a0faf68ea61260a47e388b0a4e5' (2024-04-11)
  → 'github:NixOS/nix/1c8150ac312b5f9ba1b3f6768ff43b09867e5883' (2024-04-23)
• Added input 'nix/flake-parts':
    'github:hercules-ci/flake-parts/9126214d0a59633752a136528f5f3b9aa8565b7d' (2024-04-01)
• Added input 'nix/flake-parts/nixpkgs-lib':
    follows 'nix/nixpkgs'
• Added input 'nix/pre-commit-hooks':
    'github:cachix/pre-commit-hooks.nix/40e6053ecb65fcbf12863338a6dcefb3f55f1bf8' (2024-04-12)
• Added input 'nix/pre-commit-hooks/flake-compat':
    follows 'nix'
• Added input 'nix/pre-commit-hooks/flake-utils':
    'github:numtide/flake-utils/5aed5285a952e0b949eb3ba02c12fa4fcfef535f' (2022-11-02)
• Added input 'nix/pre-commit-hooks/gitignore':
    follows 'nix'
• Added input 'nix/pre-commit-hooks/nixpkgs':
    follows 'nix/nixpkgs'
• Added input 'nix/pre-commit-hooks/nixpkgs-stable':
    follows 'nix/nixpkgs'

flake.lock

@@ -16,6 +16,42 @@
         "type": "github"
       }
     },
+    "flake-parts": {
+      "inputs": {
+        "nixpkgs-lib": [
+          "nix",
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1712014858,
+        "narHash": "sha256-sB4SWl2lX95bExY2gMFG5HIzvva5AVMJd4Igm+GpZNw=",
+        "owner": "hercules-ci",
+        "repo": "flake-parts",
+        "rev": "9126214d0a59633752a136528f5f3b9aa8565b7d",
+        "type": "github"
+      },
+      "original": {
+        "owner": "hercules-ci",
+        "repo": "flake-parts",
+        "type": "github"
+      }
+    },
+    "flake-utils": {
+      "locked": {
+        "lastModified": 1667395993,
+        "narHash": "sha256-nuEHfE/LcWyuSWnS8t12N1wc105Qtau+/OdUAjtQ0rA=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "5aed5285a952e0b949eb3ba02c12fa4fcfef535f",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
     "libgit2": {
       "flake": false,
       "locked": {
@@ -35,23 +71,25 @@
     "nix": {
       "inputs": {
         "flake-compat": "flake-compat",
+        "flake-parts": "flake-parts",
         "libgit2": "libgit2",
         "nixpkgs": [
           "nixpkgs"
         ],
-        "nixpkgs-regression": "nixpkgs-regression"
+        "nixpkgs-regression": "nixpkgs-regression",
+        "pre-commit-hooks": "pre-commit-hooks"
       },
       "locked": {
-        "lastModified": 1712849398,
+        "lastModified": 1713874370,
-        "narHash": "sha256-10z/SoidVl9/lh56cMLj7ntJZHtVrumFvmn1YEqXmaM=",
+        "narHash": "sha256-gW1mO/CvsQQ5gvgiwzxsGhPFI/tx30NING+qgF5Do0s=",
         "owner": "NixOS",
         "repo": "nix",
-        "rev": "60824fa97c588a0faf68ea61260a47e388b0a4e5",
+        "rev": "1c8150ac312b5f9ba1b3f6768ff43b09867e5883",
         "type": "github"
       },
       "original": {
         "owner": "NixOS",
-        "ref": "2.21-maintenance",
+        "ref": "2.22-maintenance",
         "repo": "nix",
         "type": "github"
       }
@@ -88,6 +126,38 @@
         "type": "github"
       }
     },
+    "pre-commit-hooks": {
+      "inputs": {
+        "flake-compat": [
+          "nix"
+        ],
+        "flake-utils": "flake-utils",
+        "gitignore": [
+          "nix"
+        ],
+        "nixpkgs": [
+          "nix",
+          "nixpkgs"
+        ],
+        "nixpkgs-stable": [
+          "nix",
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1712897695,
+        "narHash": "sha256-nMirxrGteNAl9sWiOhoN5tIHyjBbVi5e2tgZUgZlK3Y=",
+        "owner": "cachix",
+        "repo": "pre-commit-hooks.nix",
+        "rev": "40e6053ecb65fcbf12863338a6dcefb3f55f1bf8",
+        "type": "github"
+      },
+      "original": {
+        "owner": "cachix",
+        "repo": "pre-commit-hooks.nix",
+        "type": "github"
+      }
+    },
     "root": {
       "inputs": {
         "nix": "nix",

flake.nix

@@ -2,7 +2,7 @@
   description = "A Nix-based continuous build system";
 
   inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-23.11-small";
-  inputs.nix.url = "github:NixOS/nix/2.21-maintenance";
+  inputs.nix.url = "github:NixOS/nix/2.22-maintenance";
   inputs.nix.inputs.nixpkgs.follows = "nixpkgs";
 
   outputs = { self, nixpkgs, nix }:

src/hydra-eval-jobs/hydra-eval-jobs.cc

@@ -102,8 +102,8 @@ static std::string queryMetaStrings(EvalState & state, PackageInfo & drv, const
             for (unsigned int n = 0; n < v.listSize(); ++n)
                 rec(*v.listElems()[n]);
         else if (v.type() == nAttrs) {
-            auto a = v.attrs->find(state.symbols.create(subAttribute));
+            auto a = v.attrs()->find(state.symbols.create(subAttribute));
-            if (a != v.attrs->end())
+            if (a != v.attrs()->end())
                 res.push_back(std::string(state.forceString(*a->value, a->pos, "while evaluating meta attributes")));
         }
     };
@@ -138,12 +138,12 @@ static void worker(
 
         callFlake(state, lockedFlake, *vFlake);
 
-        auto vOutputs = vFlake->attrs->get(state.symbols.create("outputs"))->value;
+        auto vOutputs = vFlake->attrs()->get(state.symbols.create("outputs"))->value;
         state.forceValue(*vOutputs, noPos);
 
-        auto aHydraJobs = vOutputs->attrs->get(state.symbols.create("hydraJobs"));
+        auto aHydraJobs = vOutputs->attrs()->get(state.symbols.create("hydraJobs"));
         if (!aHydraJobs)
-            aHydraJobs = vOutputs->attrs->get(state.symbols.create("checks"));
+            aHydraJobs = vOutputs->attrs()->get(state.symbols.create("checks"));
         if (!aHydraJobs)
             throw Error("flake '%s' does not provide any Hydra jobs or checks", flakeRef);
 
@@ -204,9 +204,9 @@ static void worker(
                 job["isChannel"] = drv->queryMetaBool("isHydraChannel", false);
 
                 /* If this is an aggregate, then get its constituents. */
-                auto a = v->attrs->get(state.symbols.create("_hydraAggregate"));
+                auto a = v->attrs()->get(state.symbols.create("_hydraAggregate"));
                 if (a && state.forceBool(*a->value, a->pos, "while evaluating the `_hydraAggregate` attribute")) {
-                    auto a = v->attrs->get(state.symbols.create("constituents"));
+                    auto a = v->attrs()->get(state.symbols.create("constituents"));
                     if (!a)
                         state.error<EvalError>("derivation must have a ‘constituents’ attribute").debugThrow();
 
@@ -260,7 +260,7 @@ static void worker(
             else if (v->type() == nAttrs) {
                 auto attrs = nlohmann::json::array();
                 StringSet ss;
-                for (auto & i : v->attrs->lexicographicOrder(state.symbols)) {
+                for (auto & i : v->attrs()->lexicographicOrder(state.symbols)) {
                     std::string name(state.symbols[i->name]);
                     if (name.find(' ') != std::string::npos) {
                         printError("skipping job with illegal name '%s'", name);
@@ -368,7 +368,7 @@ int main(int argc, char * * argv)
                             ]()
                             {
                                 try {
-                                    EvalState state(myArgs.searchPath, openStore());
+                                    EvalState state(myArgs.lookupPath, openStore());
                                     Bindings & autoArgs = *myArgs.getAutoArgs(state);
                                     worker(state, autoArgs, *to, *from);
                                 } catch (Error & e) {