Use ref<Store> for localStore/destStore

As suggested by pennae.
The stores don't need to be nullable, so we initialize them right in the
constructor of `State`.

(cherry picked from commit 4b2720816d24c2e9770d1d65b73dbc8974c6dc1d)

The lix changes 7bf3d0fa2aac73a838ee91e1170034dfe3722159...949a5615405d24294abab4d3dfb05958d87c32d6 have caused build errors which are addressed with the changes to hydra herein as well as additional changes in lix.

Fixes: #36

Flake lock file updates:

• Updated input 'lix':
    'git+https://git.lix.systems/lix-project/lix?ref=refs/heads/main&rev=b918f1c307b314daa44407bac60046630f13ed48' (2025-03-27)
  → 'git+https://git.lix.systems/lix-project/lix?ref=refs/heads/main&rev=2ef4b69760af183792a740f425eb371a6aeb0009' (2025-04-06)

Co-authored-by: benaryorg <binary@benary.org>
Signed-off-by: benaryorg <binary@benary.org>

flake.lock

@@ -28,11 +28,11 @@
         "pre-commit-hooks": "pre-commit-hooks"
       },
       "locked": {
-        "lastModified": 1743065774,
-        "narHash": "sha256-aC1lwnqwHbYRsPfx+lRi32fHRcln0xhIzf0Q7/Lg+vQ=",
+        "lastModified": 1743964165,
+        "narHash": "sha256-5vXjK5W+RIveud/Qn4OyVqrZi4pUDefKZsny33dDj+s=",
         "ref": "refs/heads/main",
-        "rev": "b918f1c307b314daa44407bac60046630f13ed48",
-        "revCount": 17742,
+        "rev": "2ef4b69760af183792a740f425eb371a6aeb0009",
+        "revCount": 17767,
         "type": "git",
         "url": "https://git.lix.systems/lix-project/lix"
       },

src/hydra-queue-runner/build-remote.cc

@@ -654,7 +654,7 @@ void State::buildRemote(AsyncIoRoot & aio,
             outputs.insert(realisation.outPath);
 
         /* Copy the output paths. */
-        if (!machine->isLocalhost() || localStore != std::shared_ptr<Store>(destStore)) {
+        if (!machine->isLocalhost() || localStore != destStore) {
             updateStep(ssReceivingOutputs);
 
             MaintainCount<counter> mc(nrStepsCopyingFrom);

src/hydra-queue-runner/builder.cc

@@ -183,7 +183,7 @@ State::StepResult State::doBuildStep(AsyncIoRoot & aio,
             /* Upload the log file to the binary cache. FIXME: should
                be done on a worker thread. */
             try {
-                auto store = destStore.dynamic_pointer_cast<BinaryCacheStore>();
+                auto store = destStore.try_cast_shared<BinaryCacheStore>();
                 if (uploadLogsToBinaryCache && store && pathExists(result.logFile)) {
                     store->upsertFile("log/" + std::string(step->drvPath.to_string()), readFile(result.logFile), "text/plain; charset=utf-8");
                     unlink(result.logFile.c_str());

src/hydra-queue-runner/hydra-queue-runner.cc

@@ -102,11 +102,21 @@ State::PromMetrics::PromMetrics()
 
 }
 
-State::State(std::optional<std::string> metricsAddrOpt)
+State::State(std::optional<std::string> metricsAddrOpt, AsyncIoRoot & aio)
     : config(std::make_unique<HydraConfig>())
     , maxUnsupportedTime(config->getIntOption("max_unsupported_time", 0))
     , dbPool(config->getIntOption("max_db_connections", 128))
     , localWorkThrottler(static_cast<ptrdiff_t>(config->getIntOption("max_local_worker_threads", std::min(maxSupportedLocalWorkers, std::max(4u, std::thread::hardware_concurrency()) - 2))))
+    , localStore([&]() {
+        StoreConfig::Params localParams;
+        localParams["max-connections"] = "16";
+        localParams["max-connection-age"] = "600";
+        return aio.blockOn(openStore(getEnv("NIX_REMOTE").value_or(""), localParams));
+    }())
+    , _destStore([&](){
+        auto storeUri = config->getStrOption("store_uri");
+        return storeUri == "" ? ref<Store>{*localStore} : aio.blockOn(openStore(storeUri));
+    }())
     , maxOutputSize(config->getIntOption("max_output_size", 2ULL << 30))
     , maxLogSize(config->getIntOption("max_log_size", 64ULL << 20))
     , uploadLogsToBinaryCache(config->getBoolOption("upload_logs_to_binary_cache", false))
@@ -145,7 +155,7 @@ nix::MaintainCount<counter> State::startDbUpdate()
 
 ref<Store> State::getDestStore()
 {
-    return ref<Store>(_destStore);
+    return ref<Store>{*_destStore};
 }
 
 
@@ -866,14 +876,6 @@ void State::run(AsyncIoRoot & aio, BuildID buildOne)
         << metricsAddr << "/metrics (port " << exposerPort << ")"
         << std::endl;
 
-    StoreConfig::Params localParams;
-    localParams["max-connections"] = "16";
-    localParams["max-connection-age"] = "600";
-    localStore = aio.blockOn(openStore(getEnv("NIX_REMOTE").value_or(""), localParams));
-
-    auto storeUri = config->getStrOption("store_uri");
-    _destStore = storeUri == "" ? localStore : aio.blockOn(openStore(storeUri));
-
     useSubstitutes = config->getBoolOption("use-substitutes", false);
 
     // FIXME: hacky mechanism for configuring determinism checks.
@@ -993,7 +995,7 @@ int main(int argc, char * * argv)
 
         settings.verboseBuild = true;
 
-        State state{metricsAddrOpt};
+        State state{metricsAddrOpt, aio};
         if (status)
             state.showStatus(aio);
         else if (unlock)

src/hydra-queue-runner/state.hh

@@ -454,8 +454,8 @@ private:
 
     std::atomic<time_t> lastDispatcherCheck{0};
 
-    std::shared_ptr<nix::Store> localStore;
-    std::shared_ptr<nix::Store> _destStore;
+    nix::ref<nix::Store> localStore;
+    nix::ref<nix::Store> _destStore;
 
     size_t maxOutputSize;
     size_t maxLogSize;
@@ -499,7 +499,7 @@ private:
     PromMetrics prom;
 
 public:
-    State(std::optional<std::string> metricsAddrOpt);
+    State(std::optional<std::string> metricsAddrOpt, nix::AsyncIoRoot & aio);
 
     struct BuildOptions {
         unsigned int maxSilentTime, buildTimeout, repeats;

t/scripts/hydra-send-stats.t

@@ -16,6 +16,13 @@ hydra_setup($db);
 
 my ($res, $stdout, $stderr) = captureStdoutStderr(60, ("hydra-send-stats", "--once"));
 is($stdout, "", "hydra-send-stats stdout should be empty");
+
+# Remove `unknown setting` warnings. These can happen in the dev shell with a
+# local `nix.conf` or even in tests since the tests are using a local chroot store,
+# but hydra-queue-runner sets store config for a remote store.
+# hydra-queue-runner initializes stores in its ctor now, so these warnings get propagated
+# in the tests to hydra-send-stats.
+$stderr = join "\n", grep { 0 != rindex $_, "warning: unknown setting" } split "\n", $stderr;
 is($stderr, "", "hydra-send-stats stderr should be empty");
 is($res, 0, "hydra-send-stats --once should exit zero");