WIP: Avoid custom logic copying outputs from the remote builder

We need a replacement for the nar member logic, however. And maybe also
a test that fails until this is fixed (this one should not be passing).

flake.lock

@@ -5,7 +5,6 @@
         "flake-compat": [],
         "flake-parts": [],
         "git-hooks-nix": [],
-        "nixfmt": [],
         "nixpkgs": [
           "nixpkgs"
         ],
@@ -13,16 +12,16 @@
         "nixpkgs-regression": []
       },
       "locked": {
-        "lastModified": 1739571938,
-        "narHash": "sha256-NlaLAed/xei6RWpU2HIIbDjILRC4l1NIfGeyrn7ALQs=",
+        "lastModified": 1739899400,
+        "narHash": "sha256-q/RgA4bB7zWai4oPySq9mch7qH14IEeom2P64SXdqHs=",
         "owner": "NixOS",
         "repo": "nix",
-        "rev": "ffc649d2eabdd3e678b5bcc211dd59fd06debf3e",
+        "rev": "e310c19a1aeb1ce1ed4d41d5ab2d02db596e0918",
         "type": "github"
       },
       "original": {
         "owner": "NixOS",
-        "ref": "ssh-ng-extensions-for-hydra",
+        "ref": "2.26-maintenance",
         "repo": "nix",
         "type": "github"
       }
@@ -30,16 +29,15 @@
     "nix-eval-jobs": {
       "flake": false,
       "locked": {
-        "lastModified": 1739499741,
-        "narHash": "sha256-dNMJY6+G3PwE8lIAhwetPJdA2DxCEKRXPY/EtHmdDh4=",
-        "owner": "Ericson2314",
+        "lastModified": 1739500569,
+        "narHash": "sha256-3wIReAqdTALv39gkWXLMZQvHyBOc3yPkWT2ZsItxedY=",
+        "owner": "nix-community",
         "repo": "nix-eval-jobs",
-        "rev": "de345eb4518d952c2d86261b270f2c31edecd3de",
+        "rev": "4b392b284877d203ae262e16af269f702df036bc",
         "type": "github"
       },
       "original": {
-        "owner": "Ericson2314",
-        "ref": "nix-2.27",
+        "owner": "nix-community",
         "repo": "nix-eval-jobs",
         "type": "github"
       }

flake.nix

@@ -4,7 +4,7 @@
   inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-24.11-small";
 
   inputs.nix = {
-    url = "github:NixOS/nix/ssh-ng-extensions-for-hydra";
+    url = "github:NixOS/nix/2.26-maintenance";
     inputs.nixpkgs.follows = "nixpkgs";
 
     # hide nix dev tooling from our lock file
@@ -13,11 +13,10 @@
     inputs.nixpkgs-regression.follows = "";
     inputs.nixpkgs-23-11.follows = "";
     inputs.flake-compat.follows = "";
-    inputs.nixfmt.follows = "";
   };
 
   inputs.nix-eval-jobs = {
-    url = "github:Ericson2314/nix-eval-jobs/nix-2.27";
+    url = "github:nix-community/nix-eval-jobs";
     # We want to control the deps precisely
     flake = false;
   };

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

@@ -7,7 +7,7 @@
 
 #include "build-result.hh"
 #include "path.hh"
-#include "ssh-store.hh"
+#include "legacy-ssh-store.hh"
 #include "serve-protocol.hh"
 #include "state.hh"
 #include "current-process.hh"
@@ -119,10 +119,11 @@ static BuildResult performBuild(
     Store & localStore,
     StorePath drvPath,
     const BasicDerivation & drv,
+    const ServeProto::BuildOptions & options,
     counter & nrStepsBuilding
 )
 {
-    auto kont = conn.store->buildDerivationAsync(drvPath, drv, bmNormal);
+    auto kont = conn.store->buildDerivationAsync(drvPath, drv, options);
 
     BuildResult result;
 
@@ -237,6 +238,7 @@ void RemoteResult::updateWithBuildResult(const nix::BuildResult & buildResult)
 
 void State::buildRemote(ref<Store> destStore,
     ::Machine::ptr machine, Step::ptr step,
+    const ServeProto::BuildOptions & buildOptions,
     RemoteResult & result, std::shared_ptr<ActiveStep> activeStep,
     std::function<void(StepState)> updateStep,
     NarMemberDatas & narMembers)
@@ -256,26 +258,25 @@ void State::buildRemote(ref<Store> destStore,
             .machine = machine,
             .store = [&]{
                 auto * pSpecified = std::get_if<StoreReference::Specified>(&machine->storeUri.variant);
-                if (!pSpecified || pSpecified->scheme != "ssh-ng") {
-                    throw Error("Currently, only ssh-ng:// stores are supported!");
+                if (!pSpecified || pSpecified->scheme != "ssh") {
+                    throw Error("Currently, only (legacy-)ssh stores are supported!");
                 }
 
-                auto remoteStore = machine->openStore().dynamic_pointer_cast<RemoteStore>();
-                auto remoteStoreConfig = std::dynamic_pointer_cast<SSHStoreConfig>(remoteStore);
+                auto remoteStore = machine->openStore().dynamic_pointer_cast<LegacySSHStore>();
                 assert(remoteStore);
 
+                remoteStore->connPipeSize = 1024 * 1024;
+
                 if (machine->isLocalhost()) {
-                    auto rp_new = remoteStoreConfig->remoteProgram.get();
+                    auto rp_new = remoteStore->remoteProgram.get();
                     rp_new.push_back("--builders");
                     rp_new.push_back("");
-                    const_cast<nix::Setting<Strings> &>(remoteStoreConfig->remoteProgram).assign(rp_new);
+                    const_cast<nix::Setting<Strings> &>(remoteStore->remoteProgram).assign(rp_new);
                 }
-                remoteStoreConfig->extraSshArgs = {
+                remoteStore->extraSshArgs = {
                     "-a", "-oBatchMode=yes", "-oConnectTimeout=60", "-oTCPKeepAlive=yes"
                 };
-
-                // TODO logging
-                //const_cast<nix::Setting<int> &>(remoteStore->logFD).assign(logFD.get());
+                const_cast<nix::Setting<int> &>(remoteStore->logFD).assign(logFD.get());
 
                 return nix::ref{remoteStore};
             }(),
@@ -284,10 +285,12 @@ void State::buildRemote(ref<Store> destStore,
         {
             auto activeStepState(activeStep->state_.lock());
             if (activeStepState->cancelled) throw Error("step cancelled");
+            activeStepState->pid = conn.store->getConnectionPid();
         }
 
         Finally clearPid([&]() {
             auto activeStepState(activeStep->state_.lock());
+            activeStepState->pid = -1;
 
             /* FIXME: there is a slight race here with step
                cancellation in State::processQueueChange(), which
@@ -298,10 +301,9 @@ void State::buildRemote(ref<Store> destStore,
         });
 
         Finally updateStats([&]() {
-            // TODO
-            //auto stats = conn.store->getConnectionStats();
-            //bytesReceived += stats.bytesReceived;
-            //bytesSent += stats.bytesSent;
+            auto stats = conn.store->getConnectionStats();
+            bytesReceived += stats.bytesReceived;
+            bytesSent += stats.bytesSent;
         });
 
         {
@@ -341,6 +343,7 @@ void State::buildRemote(ref<Store> destStore,
             *localStore,
             step->drvPath,
             resolvedDrv,
+            buildOptions,
             nrStepsBuilding
         );
 

src/hydra-queue-runner/builder.cc

@@ -98,6 +98,13 @@ State::StepResult State::doBuildStep(nix::ref<Store> destStore,
        it). */
     BuildID buildId;
     std::optional<StorePath> buildDrvPath;
+    // Other fields set below
+    nix::ServeProto::BuildOptions buildOptions {
+        .maxLogSize = maxLogSize,
+        .nrRepeats = step->isDeterministic ? 1u : 0u,
+        .enforceDeterminism = step->isDeterministic,
+        .keepFailed = false,
+    };
 
     auto conn(dbPool.get());
 
@@ -132,19 +139,18 @@ State::StepResult State::doBuildStep(nix::ref<Store> destStore,
             {
                 auto i = jobsetRepeats.find(std::make_pair(build2->projectName, build2->jobsetName));
                 if (i != jobsetRepeats.end())
-                    warn("jobset repeats is deprecated; nix stopped supporting this correctly a long time ago.");
+                    buildOptions.nrRepeats = std::max(buildOptions.nrRepeats, i->second);
             }
         }
         if (!build) build = *dependents.begin();
 
         buildId = build->id;
         buildDrvPath = build->drvPath;
-        settings.maxLogSize = maxLogSize;
-        settings.maxSilentTime = build->maxSilentTime;
-        settings.buildTimeout = build->buildTimeout;
+        buildOptions.maxSilentTime = build->maxSilentTime;
+        buildOptions.buildTimeout = build->buildTimeout;
 
         printInfo("performing step ‘%s’ %d times on ‘%s’ (needed by build %d and %d others)",
-            localStore->printStorePath(step->drvPath), 1, machine->storeUri.render(), buildId, (dependents.size() - 1));
+            localStore->printStorePath(step->drvPath), buildOptions.nrRepeats + 1, machine->storeUri.render(), buildId, (dependents.size() - 1));
     }
 
     if (!buildOneDone)
@@ -205,7 +211,7 @@ State::StepResult State::doBuildStep(nix::ref<Store> destStore,
 
         try {
             /* FIXME: referring builds may have conflicting timeouts. */
-            buildRemote(destStore, machine, step, result, activeStep, updateStep, narMembers);
+            buildRemote(destStore, machine, step, buildOptions, result, activeStep, updateStep, narMembers);
         } catch (Error & e) {
             if (activeStep->state_.lock()->cancelled) {
                 printInfo("marking step %d of build %d as cancelled", stepNr, buildId);

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

@@ -182,7 +182,7 @@ void State::monitorMachinesFile()
         getEnv("NIX_REMOTE_SYSTEMS").value_or(pathExists(defaultMachinesFile) ? defaultMachinesFile : ""), ":");
 
     if (machinesFiles.empty()) {
-        parseMachines("ssh-ng://localhost " +
+        parseMachines("localhost " +
             (settings.thisSystem == "x86_64-linux" ? "x86_64-linux,i686-linux" : settings.thisSystem.get())
             + " - " + std::to_string(settings.maxBuildJobs) + " 1 "
             + concatStringsSep(",", StoreConfig::getDefaultSystemFeatures()));

src/hydra-queue-runner/state.hh

@@ -20,7 +20,7 @@
 #include "store-api.hh"
 #include "sync.hh"
 #include "nar-extractor.hh"
-#include "ssh-store.hh"
+#include "legacy-ssh-store.hh"
 #include "machines.hh"
 
 
@@ -294,12 +294,12 @@ struct Machine : nix::Machine
         // Backpointer to the machine
         ptr machine;
         // Opened store
-        nix::ref<nix::RemoteStore> store;
+        nix::ref<nix::LegacySSHStore> store;
     };
 };
 
 
-struct HydraConfig;
+class HydraConfig;
 
 
 class State
@@ -542,6 +542,7 @@ private:
 
     void buildRemote(nix::ref<nix::Store> destStore,
         Machine::ptr machine, Step::ptr step,
+        const nix::ServeProto::BuildOptions & buildOptions,
         RemoteResult & result, std::shared_ptr<ActiveStep> activeStep,
         std::function<void(StepState)> updateStep,
         NarMemberDatas & narMembers);