diff --git a/flake.lock b/flake.lock
index 2ddc7c16..3c4c0f75 100644
--- a/flake.lock
+++ b/flake.lock
@@ -16,58 +16,58 @@
         "type": "github"
       }
     },
-    "lowdown-src": {
+    "libgit2": {
       "flake": false,
       "locked": {
-        "lastModified": 1633514407,
-        "narHash": "sha256-Dw32tiMjdK9t3ETl5fzGrutQTzh2rufgZV4A/BbxuD4=",
-        "owner": "kristapsdz",
-        "repo": "lowdown",
-        "rev": "d2c2b44ff6c27b936ec27358a2653caaef8f73b8",
+        "lastModified": 1697646580,
+        "narHash": "sha256-oX4Z3S9WtJlwvj0uH9HlYcWv+x1hqp8mhXl7HsLu2f0=",
+        "owner": "libgit2",
+        "repo": "libgit2",
+        "rev": "45fd9ed7ae1a9b74b957ef4f337bc3c8b3df01b5",
         "type": "github"
       },
       "original": {
-        "owner": "kristapsdz",
-        "repo": "lowdown",
+        "owner": "libgit2",
+        "repo": "libgit2",
         "type": "github"
       }
     },
     "nix": {
       "inputs": {
         "flake-compat": "flake-compat",
-        "lowdown-src": "lowdown-src",
+        "libgit2": "libgit2",
         "nixpkgs": [
           "nixpkgs"
         ],
         "nixpkgs-regression": "nixpkgs-regression"
       },
       "locked": {
-        "lastModified": 1706208340,
-        "narHash": "sha256-wNyHUEIiKKVs6UXrUzhP7RSJQv0A8jckgcuylzftl8k=",
+        "lastModified": 1715805674,
+        "narHash": "sha256-0CIBMECsA3ISJZrJcOTzi6wa3QENTKGLtOpYIOoxwxo=",
         "owner": "NixOS",
         "repo": "nix",
-        "rev": "2c4bb93ba5a97e7078896ebc36385ce172960e4e",
+        "rev": "ab48ea416a203e9ccefb70aa634e27477e4c1ac4",
         "type": "github"
       },
       "original": {
         "owner": "NixOS",
-        "ref": "2.19-maintenance",
+        "ref": "2.20-maintenance",
         "repo": "nix",
         "type": "github"
       }
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1701615100,
-        "narHash": "sha256-7VI84NGBvlCTduw2aHLVB62NvCiZUlALLqBe5v684Aw=",
+        "lastModified": 1705033721,
+        "narHash": "sha256-K5eJHmL1/kev6WuqyqqbS1cdNnSidIZ3jeqJ7GbrYnQ=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "e9f06adb793d1cca5384907b3b8a4071d5d7cb19",
+        "rev": "a1982c92d8980a0114372973cbdfe0a307f1bdea",
         "type": "github"
       },
       "original": {
         "owner": "NixOS",
-        "ref": "nixos-23.05",
+        "ref": "nixos-23.05-small",
         "repo": "nixpkgs",
         "type": "github"
       }
diff --git a/flake.nix b/flake.nix
index 30aa61c0..31a38416 100644
--- a/flake.nix
+++ b/flake.nix
@@ -1,8 +1,8 @@
 {
   description = "A Nix-based continuous build system";
 
-  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-23.05";
-  inputs.nix.url = "github:NixOS/nix/2.19-maintenance";
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-23.05-small";
+  inputs.nix.url = "github:NixOS/nix/2.20-maintenance";
   inputs.nix.inputs.nixpkgs.follows = "nixpkgs";
 
   # TODO get rid of this once https://github.com/NixOS/nix/pull/9546 is
@@ -180,13 +180,9 @@
                 root=d7f16a3412e01a43a414535b16007c6931d3a9c7
                 </gitea_authorization>
               '';
+              nixpkgs.config.permittedInsecurePackages = [ "gitea-1.19.4" ];
               nix = {
-                distributedBuilds = true;
-                buildMachines = [{
-                  hostName = "localhost";
-                  systems = [ system ];
-                }];
-                binaryCaches = [ ];
+                settings.substituters = [ ];
               };
               services.gitea = {
                 enable = true;
@@ -202,7 +198,7 @@
             testScript =
               let
                 scripts.mktoken = pkgs.writeText "token.sql" ''
-                  INSERT INTO access_token (id, uid, name, created_unix, updated_unix, token_hash, token_salt, token_last_eight) VALUES (1, 1, 'hydra', 1617107360, 1617107360, 'a930f319ca362d7b49a4040ac0af74521c3a3c3303a86f327b01994430672d33b6ec53e4ea774253208686c712495e12a486', 'XRjWE9YW0g', '31d3a9c7');
+                  INSERT INTO access_token (id, uid, name, created_unix, updated_unix, token_hash, token_salt, token_last_eight, scope) VALUES (1, 1, 'hydra', 1617107360, 1617107360, 'a930f319ca362d7b49a4040ac0af74521c3a3c3303a86f327b01994430672d33b6ec53e4ea774253208686c712495e12a486', 'XRjWE9YW0g', '31d3a9c7', 'all');
                 '';
 
                 scripts.git-setup = pkgs.writeShellScript "setup.sh" ''
@@ -357,9 +353,9 @@
 
                 response = json.loads(data)
 
-                assert len(response) == 2, "Expected exactly two status updates for latest commit!"
-                assert response[0]['status'] == "success", "Expected latest status to be success!"
-                assert response[1]['status'] == "pending", "Expected first status to be pending!"
+                assert len(response) == 2, "Expected exactly three status updates for latest commit (queued, finished)!"
+                assert response[0]['status'] == "success", "Expected finished status to be success!"
+                assert response[1]['status'] == "pending", "Expected queued status to be pending!"
 
                 machine.shutdown()
               '';
diff --git a/src/hydra-eval-jobs/hydra-eval-jobs.cc b/src/hydra-eval-jobs/hydra-eval-jobs.cc
index 5cfc3a52..1d7de74b 100644
--- a/src/hydra-eval-jobs/hydra-eval-jobs.cc
+++ b/src/hydra-eval-jobs/hydra-eval-jobs.cc
@@ -89,7 +89,7 @@ struct MyArgs : MixEvalArgs, MixCommonArgs, RootArgs
 
 static MyArgs myArgs;
 
-static std::string queryMetaStrings(EvalState & state, DrvInfo & drv, const std::string & name, const std::string & subAttribute)
+static std::string queryMetaStrings(EvalState & state, PackageInfo & drv, const std::string & name, const std::string & subAttribute)
 {
     Strings res;
     std::function<void(Value & v)> rec;
@@ -181,7 +181,7 @@ static void worker(
                 // CA derivations do not have static output paths, so we
                 // have to defensively not query output paths in case we
                 // encounter one.
-                DrvInfo::Outputs outputs = drv->queryOutputs(
+                PackageInfo::Outputs outputs = drv->queryOutputs(
                     !experimentalFeatureSettings.isEnabled(Xp::CaDerivations));
 
                 if (drv->querySystem() == "unknown")
diff --git a/src/hydra-queue-runner/build-remote.cc b/src/hydra-queue-runner/build-remote.cc
index 4ce1d1b8..e6852c38 100644
--- a/src/hydra-queue-runner/build-remote.cc
+++ b/src/hydra-queue-runner/build-remote.cc
@@ -1,5 +1,6 @@
 #include "build-result.hh"
 #include "serve-protocol.hh"
+#include "serve-protocol-impl.hh"
 #include "state.hh"
 #include "current-process.hh"
 #include "processes.hh"
@@ -99,7 +100,7 @@ void RemoteResult::updateWithBuildResult(const nix::BuildResult & buildResult)
 
 void State::buildRemote(ref<Store> destStore,
     ::Machine::ptr machine, Step::ptr step,
-    const BuildOptions & buildOptions,
+    const ServeProto::BuildOptions & buildOptions,
     RemoteResult & result, std::shared_ptr<ActiveStep> activeStep,
     std::function<void(StepState)> updateStep,
     NarMemberDatas & narMembers)
@@ -124,7 +125,7 @@ void State::buildRemote(ref<Store> destStore,
             "--timeout", std::to_string(buildOptions.buildTimeout),
             "--max-build-log-size", std::to_string(buildOptions.maxLogSize),
             "--max-output-size", std::to_string(maxOutputSize),
-            "--repeat", std::to_string(buildOptions.repeats),
+            "--repeat", std::to_string(buildOptions.nrRepeats),
             "--log-file", result.logFile,
             // FIXME: step->isDeterministic
         };
@@ -143,7 +144,7 @@ void State::buildRemote(ref<Store> destStore,
         {
             auto activeStepState(activeStep->state_.lock());
             if (activeStepState->cancelled) throw Error("step cancelled");
-            activeStepState->pid = child.sshPid;
+            activeStepState->pid = child->sshPid;
         }
 
         Finally clearPid([&]() {
diff --git a/src/hydra-queue-runner/builder.cc b/src/hydra-queue-runner/builder.cc
index fb5e8b64..7cd8fc35 100644
--- a/src/hydra-queue-runner/builder.cc
+++ b/src/hydra-queue-runner/builder.cc
@@ -99,10 +99,13 @@ State::StepResult State::doBuildStep(nix::ref<Store> destStore,
        it). */
     BuildID buildId;
     std::optional<StorePath> buildDrvPath;
-    BuildOptions buildOptions;
-    buildOptions.repeats = step->isDeterministic ? 1 : 0;
-    buildOptions.maxLogSize = maxLogSize;
-    buildOptions.enforceDeterminism = step->isDeterministic;
+    // Other fields set below
+    nix::ServeProto::BuildOptions buildOptions {
+        .maxLogSize = maxLogSize,
+        .nrRepeats = step->isDeterministic ? 1u : 0u,
+        .enforceDeterminism = step->isDeterministic,
+        .keepFailed = false,
+    };
 
     auto conn(dbPool.get());
 
@@ -137,7 +140,7 @@ State::StepResult State::doBuildStep(nix::ref<Store> destStore,
             {
                 auto i = jobsetRepeats.find(std::make_pair(build2->projectName, build2->jobsetName));
                 if (i != jobsetRepeats.end())
-                    buildOptions.repeats = std::max(buildOptions.repeats, i->second);
+                    buildOptions.nrRepeats = std::max(buildOptions.nrRepeats, i->second);
             }
         }
         if (!build) build = *dependents.begin();
@@ -148,7 +151,7 @@ State::StepResult State::doBuildStep(nix::ref<Store> destStore,
         buildOptions.buildTimeout = build->buildTimeout;
 
         printInfo("performing step ‘%s’ %d times on ‘%s’ (needed by build %d and %d others)",
-            localStore->printStorePath(step->drvPath), buildOptions.repeats + 1, machine->sshName, buildId, (dependents.size() - 1));
+            localStore->printStorePath(step->drvPath), buildOptions.nrRepeats + 1, machine->sshName, buildId, (dependents.size() - 1));
     }
 
     if (!buildOneDone)
diff --git a/src/hydra-queue-runner/dispatcher.cc b/src/hydra-queue-runner/dispatcher.cc
index f5d9d3e3..6d738ded 100644
--- a/src/hydra-queue-runner/dispatcher.cc
+++ b/src/hydra-queue-runner/dispatcher.cc
@@ -231,11 +231,11 @@ system_time State::doDispatch()
         sort(machinesSorted.begin(), machinesSorted.end(),
             [](const MachineInfo & a, const MachineInfo & b) -> bool
             {
-                float ta = std::round(a.currentJobs / a.machine->speedFactorFloat);
-                float tb = std::round(b.currentJobs / b.machine->speedFactorFloat);
+                float ta = std::round(a.currentJobs / a.machine->speedFactor);
+                float tb = std::round(b.currentJobs / b.machine->speedFactor);
                 return
                     ta != tb ? ta < tb :
-                    a.machine->speedFactorFloat != b.machine->speedFactorFloat ? a.machine->speedFactorFloat > b.machine->speedFactorFloat :
+                    a.machine->speedFactor != b.machine->speedFactor ? a.machine->speedFactor > b.machine->speedFactor :
                     a.currentJobs > b.currentJobs;
             });
 
diff --git a/src/hydra-queue-runner/hydra-queue-runner.cc b/src/hydra-queue-runner/hydra-queue-runner.cc
index e9bfa4e6..073d8d4e 100644
--- a/src/hydra-queue-runner/hydra-queue-runner.cc
+++ b/src/hydra-queue-runner/hydra-queue-runner.cc
@@ -155,29 +155,27 @@ void State::parseMachines(const std::string & contents)
         auto machine = std::make_shared<::Machine>(nix::Machine {
             // `storeUri`, not yet used
             "",
-            // `systemTypes`, not yet used
-            {},
+            // `systemTypes`
+            tokenizeString<StringSet>(tokens[1], ","),
             // `sshKey`
             tokens[2] == "-" ? "" : tokens[2],
             // `maxJobs`
             tokens[3] != ""
                 ? string2Int<MaxJobs>(tokens[3]).value()
                 : 1,
-            // `speedFactor`, not yet used
-            1,
+            // `speedFactor`
+            atof(tokens[4].c_str()),
             // `supportedFeatures`
             std::move(supportedFeatures),
             // `mandatoryFeatures`
             std::move(mandatoryFeatures),
             // `sshPublicHostKey`
             tokens[7] != "" && tokens[7] != "-"
-                ? base64Decode(tokens[7])
+                ? tokens[7]
                 : "",
         });
 
         machine->sshName = tokens[0];
-        machine->systemTypesSet = tokenizeString<StringSet>(tokens[1], ",");
-        machine->speedFactorFloat = atof(tokens[4].c_str());
 
         /* Re-use the State object of the previous machine with the
            same name. */
@@ -640,7 +638,7 @@ void State::dumpStatus(Connection & conn)
 
                 json machine = {
                     {"enabled",  m->enabled},
-                    {"systemTypes", m->systemTypesSet},
+                    {"systemTypes", m->systemTypes},
                     {"supportedFeatures", m->supportedFeatures},
                     {"mandatoryFeatures", m->mandatoryFeatures},
                     {"nrStepsDone", s->nrStepsDone.load()},
@@ -927,10 +925,17 @@ void State::run(BuildID buildOne)
     while (true) {
         try {
             auto conn(dbPool.get());
-            receiver dumpStatus_(*conn, "dump_status");
-            while (true) {
-                conn->await_notification();
-                dumpStatus(*conn);
+            try {
+                receiver dumpStatus_(*conn, "dump_status");
+                while (true) {
+                    conn->await_notification();
+                    dumpStatus(*conn);
+                }
+            } catch (pqxx::broken_connection & connEx) {
+                printMsg(lvlError, "main thread: %s", connEx.what());
+                printMsg(lvlError, "main thread: Reconnecting in 10s");
+                conn.markBad();
+                sleep(10);
             }
         } catch (std::exception & e) {
             printMsg(lvlError, "main thread: %s", e.what());
diff --git a/src/hydra-queue-runner/nar-extractor.cc b/src/hydra-queue-runner/nar-extractor.cc
index 3c6857bf..61299ecd 100644
--- a/src/hydra-queue-runner/nar-extractor.cc
+++ b/src/hydra-queue-runner/nar-extractor.cc
@@ -6,7 +6,46 @@
 
 using namespace nix;
 
-struct Extractor : ParseSink
+
+struct NarMemberConstructor : CreateRegularFileSink
+{
+    NarMemberData & curMember;
+
+    HashSink hashSink = HashSink { HashAlgorithm::SHA256 };
+
+    std::optional<uint64_t> expectedSize;
+
+    NarMemberConstructor(NarMemberData & curMember)
+        : curMember(curMember)
+    { }
+
+    void isExecutable() override
+    {
+    }
+
+    void preallocateContents(uint64_t size) override
+    {
+        expectedSize = size;
+    }
+
+    void operator () (std::string_view data) override
+    {
+        assert(expectedSize);
+        *curMember.fileSize += data.size();
+        hashSink(data);
+        if (curMember.contents) {
+            curMember.contents->append(data);
+        }
+        assert(curMember.fileSize <= expectedSize);
+        if (curMember.fileSize == expectedSize) {
+            auto [hash, len] = hashSink.finish();
+            assert(curMember.fileSize == len);
+            curMember.sha256 = hash;
+        }
+    }
+};
+
+struct Extractor : FileSystemObjectSink
 {
     std::unordered_set<Path> filesToKeep {
         "/nix-support/hydra-build-products",
@@ -15,7 +54,6 @@ struct Extractor : ParseSink
     };
 
     NarMemberDatas & members;
-    NarMemberData * curMember = nullptr;
     Path prefix;
 
     Extractor(NarMemberDatas & members, const Path & prefix)
@@ -27,53 +65,22 @@ struct Extractor : ParseSink
         members.insert_or_assign(prefix + path, NarMemberData { .type = SourceAccessor::Type::tDirectory });
     }
 
-    void createRegularFile(const Path & path) override
+    void createRegularFile(const Path & path, std::function<void(CreateRegularFileSink &)> func) override
     {
-        curMember = &members.insert_or_assign(prefix + path, NarMemberData {
-            .type = SourceAccessor::Type::tRegular,
-            .fileSize = 0,
-            .contents = filesToKeep.count(path) ? std::optional("") : std::nullopt,
-        }).first->second;
-    }
-
-    std::optional<uint64_t> expectedSize;
-    std::unique_ptr<HashSink> hashSink;
-
-    void preallocateContents(uint64_t size) override
-    {
-        expectedSize = size;
-        hashSink = std::make_unique<HashSink>(htSHA256);
-    }
-
-    void receiveContents(std::string_view data) override
-    {
-        assert(expectedSize);
-        assert(curMember);
-        assert(hashSink);
-        *curMember->fileSize += data.size();
-        (*hashSink)(data);
-        if (curMember->contents) {
-            curMember->contents->append(data);
-        }
-        assert(curMember->fileSize <= expectedSize);
-        if (curMember->fileSize == expectedSize) {
-            auto [hash, len] = hashSink->finish();
-            assert(curMember->fileSize == len);
-            curMember->sha256 = hash;
-            hashSink.reset();
-        }
+        NarMemberConstructor nmc {
+            members.insert_or_assign(prefix + path, NarMemberData {
+                .type = SourceAccessor::Type::tRegular,
+                .fileSize = 0,
+                .contents = filesToKeep.count(path) ? std::optional("") : std::nullopt,
+            }).first->second,
+        };
+        func(nmc);
     }
 
     void createSymlink(const Path & path, const std::string & target) override
     {
         members.insert_or_assign(prefix + path, NarMemberData { .type = SourceAccessor::Type::tSymlink });
     }
-
-    void isExecutable() override
-    { }
-
-    void closeRegularFile() override
-    { }
 };
 
 
diff --git a/src/hydra-queue-runner/queue-monitor.cc b/src/hydra-queue-runner/queue-monitor.cc
index d7214c43..1bd51f5a 100644
--- a/src/hydra-queue-runner/queue-monitor.cc
+++ b/src/hydra-queue-runner/queue-monitor.cc
@@ -10,8 +10,14 @@ using namespace nix;
 void State::queueMonitor()
 {
     while (true) {
+        auto conn(dbPool.get());
         try {
-            queueMonitorLoop();
+            queueMonitorLoop(*conn);
+        } catch (pqxx::broken_connection & e) {
+            printMsg(lvlError, "queue monitor: %s", e.what());
+            printMsg(lvlError, "queue monitor: Reconnecting in 10s");
+            conn.markBad();
+            sleep(10);
         } catch (std::exception & e) {
             printError("queue monitor: %s", e.what());
             sleep(10); // probably a DB problem, so don't retry right away
@@ -20,16 +26,14 @@ void State::queueMonitor()
 }
 
 
-void State::queueMonitorLoop()
+void State::queueMonitorLoop(Connection & conn)
 {
-    auto conn(dbPool.get());
-
-    receiver buildsAdded(*conn, "builds_added");
-    receiver buildsRestarted(*conn, "builds_restarted");
-    receiver buildsCancelled(*conn, "builds_cancelled");
-    receiver buildsDeleted(*conn, "builds_deleted");
-    receiver buildsBumped(*conn, "builds_bumped");
-    receiver jobsetSharesChanged(*conn, "jobset_shares_changed");
+    receiver buildsAdded(conn, "builds_added");
+    receiver buildsRestarted(conn, "builds_restarted");
+    receiver buildsCancelled(conn, "builds_cancelled");
+    receiver buildsDeleted(conn, "builds_deleted");
+    receiver buildsBumped(conn, "builds_bumped");
+    receiver jobsetSharesChanged(conn, "jobset_shares_changed");
 
     auto destStore = getDestStore();
 
@@ -39,17 +43,17 @@ void State::queueMonitorLoop()
     while (!quit) {
         localStore->clearPathInfoCache();
 
-        bool done = getQueuedBuilds(*conn, destStore, lastBuildId);
+        bool done = getQueuedBuilds(conn, destStore, lastBuildId);
 
         if (buildOne && buildOneDone) quit = true;
 
         /* Sleep until we get notification from the database about an
            event. */
         if (done && !quit) {
-            conn->await_notification();
+            conn.await_notification();
             nrQueueWakeups++;
         } else
-            conn->get_notifs();
+            conn.get_notifs();
 
         if (auto lowestId = buildsAdded.get()) {
             lastBuildId = std::min(lastBuildId, static_cast<unsigned>(std::stoul(*lowestId) - 1));
@@ -61,11 +65,11 @@ void State::queueMonitorLoop()
         }
         if (buildsCancelled.get() || buildsDeleted.get() || buildsBumped.get()) {
             printMsg(lvlTalkative, "got notification: builds cancelled or bumped");
-            processQueueChange(*conn);
+            processQueueChange(conn);
         }
         if (jobsetSharesChanged.get()) {
             printMsg(lvlTalkative, "got notification: jobset shares changed");
-            processJobsetSharesChange(*conn);
+            processJobsetSharesChange(conn);
         }
     }
 
@@ -696,7 +700,7 @@ BuildOutput State::getBuildOutputCached(Connection & conn, nix::ref<nix::Store>
                 product.fileSize = row[2].as<off_t>();
             }
             if (!row[3].is_null())
-                product.sha256hash = Hash::parseAny(row[3].as<std::string>(), htSHA256);
+                product.sha256hash = Hash::parseAny(row[3].as<std::string>(), HashAlgorithm::SHA256);
             if (!row[4].is_null())
                 product.path = row[4].as<std::string>();
             product.name = row[5].as<std::string>();
diff --git a/src/hydra-queue-runner/state.hh b/src/hydra-queue-runner/state.hh
index 608441b4..589ca6d8 100644
--- a/src/hydra-queue-runner/state.hh
+++ b/src/hydra-queue-runner/state.hh
@@ -22,6 +22,7 @@
 #include "sync.hh"
 #include "nar-extractor.hh"
 #include "machines.hh"
+#include "serve-protocol.hh"
 
 
 typedef unsigned int BuildID;
@@ -242,14 +243,6 @@ struct Machine : nix::Machine
        we are not yet used to, but once we are, we don't need this. */
     std::string sshName;
 
-    /* TODO Get rid once `nix::Machine::systemTypes` is a set not
-       vector. */
-    std::set<std::string> systemTypesSet;
-
-    /* TODO Get rid once `nix::Machine::systemTypes` is a `float` not
-       an `int`. */
-    float speedFactorFloat = 1.0;
-
     struct State {
         typedef std::shared_ptr<State> ptr;
         counter currentJobs{0};
@@ -276,7 +269,7 @@ struct Machine : nix::Machine
     {
         /* Check that this machine is of the type required by the
            step. */
-        if (!systemTypesSet.count(step->drv->platform == "builtin" ? nix::settings.thisSystem : step->drv->platform))
+        if (!systemTypes.count(step->drv->platform == "builtin" ? nix::settings.thisSystem : step->drv->platform))
             return false;
 
         /* Check that the step requires all mandatory features of this
@@ -436,7 +429,7 @@ private:
 
     /* How often the build steps of a jobset should be repeated in
        order to detect non-determinism. */
-    std::map<std::pair<std::string, std::string>, unsigned int> jobsetRepeats;
+    std::map<std::pair<std::string, std::string>, size_t> jobsetRepeats;
 
     bool uploadLogsToBinaryCache;
 
@@ -465,12 +458,6 @@ private:
 public:
     State(std::optional<std::string> metricsAddrOpt);
 
-    struct BuildOptions {
-        unsigned int maxSilentTime, buildTimeout, repeats;
-        size_t maxLogSize;
-        bool enforceDeterminism;
-    };
-
 private:
 
     nix::MaintainCount<counter> startDbUpdate();
@@ -503,7 +490,7 @@ private:
 
     void queueMonitor();
 
-    void queueMonitorLoop();
+    void queueMonitorLoop(Connection & conn);
 
     /* Check the queue for new builds. */
     bool getQueuedBuilds(Connection & conn,
@@ -555,7 +542,7 @@ private:
 
     void buildRemote(nix::ref<nix::Store> destStore,
         Machine::ptr machine, Step::ptr step,
-        const BuildOptions & buildOptions,
+        const nix::ServeProto::BuildOptions & buildOptions,
         RemoteResult & result, std::shared_ptr<ActiveStep> activeStep,
         std::function<void(StepState)> updateStep,
         NarMemberDatas & narMembers);
diff --git a/src/lib/Hydra/Controller/Build.pm b/src/lib/Hydra/Controller/Build.pm
index c3869838..6b25ff80 100644
--- a/src/lib/Hydra/Controller/Build.pm
+++ b/src/lib/Hydra/Controller/Build.pm
@@ -15,6 +15,7 @@ use Nix::Config;
 use List::SomeUtils qw(all);
 use Encode;
 use JSON::PP;
+use WWW::Form::UrlEncoded::PP qw();
 
 use feature 'state';
 
@@ -141,7 +142,7 @@ sub view_nixlog : Chained('buildChain') PathPart('nixlog') {
     $c->stash->{step} = $step;
 
     my $drvPath = $step->drvpath;
-    my $log_uri = $c->uri_for($c->controller('Root')->action_for("log"), [basename($drvPath)]);
+    my $log_uri = $c->uri_for($c->controller('Root')->action_for("log"), [WWW::Form::UrlEncoded::PP::url_encode(basename($drvPath))]);
     showLog($c, $mode, $log_uri);
 }
 
@@ -150,7 +151,7 @@ sub view_log : Chained('buildChain') PathPart('log') {
     my ($self, $c, $mode) = @_;
 
     my $drvPath = $c->stash->{build}->drvpath;
-    my $log_uri = $c->uri_for($c->controller('Root')->action_for("log"), [basename($drvPath)]);
+    my $log_uri = $c->uri_for($c->controller('Root')->action_for("log"), [WWW::Form::UrlEncoded::PP::url_encode(basename($drvPath))]);
     showLog($c, $mode, $log_uri);
 }
 
diff --git a/src/lib/Hydra/Controller/Root.pm b/src/lib/Hydra/Controller/Root.pm
index 548cfac3..e6c3049f 100644
--- a/src/lib/Hydra/Controller/Root.pm
+++ b/src/lib/Hydra/Controller/Root.pm
@@ -16,6 +16,7 @@ use List::Util qw[min max];
 use List::SomeUtils qw{any};
 use Net::Prometheus;
 use Types::Standard qw/StrMatch/;
+use WWW::Form::UrlEncoded::PP qw();
 
 use constant NARINFO_REGEX => qr{^([a-z0-9]{32})\.narinfo$};
 # e.g.: https://hydra.example.com/realisations/sha256:a62128132508a3a32eef651d6467695944763602f226ac630543e947d9feb140!out.doi
@@ -553,7 +554,7 @@ sub log :Local :Args(1) {
     my $logPrefix = $c->config->{log_prefix};
 
     if (defined $logPrefix) {
-        $c->res->redirect($logPrefix . "log/" . basename($drvPath));
+        $c->res->redirect($logPrefix . "log/" . WWW::Form::UrlEncoded::PP::url_encode(basename($drvPath)));
     } else {
         notFound($c, "The build log of $drvPath is not available.");
     }
diff --git a/src/lib/Hydra/Plugin/GiteaStatus.pm b/src/lib/Hydra/Plugin/GiteaStatus.pm
index 426c93f5..f3498941 100644
--- a/src/lib/Hydra/Plugin/GiteaStatus.pm
+++ b/src/lib/Hydra/Plugin/GiteaStatus.pm
@@ -88,10 +88,6 @@ sub buildQueued {
     common(@_, [], 0);
 }
 
-sub buildStarted {
-    common(@_, [], 1);
-}
-
 sub buildFinished {
     common(@_, 2);
 }
diff --git a/src/root/auth.tt b/src/root/auth.tt
index d1539765..d49ba5bd 100644
--- a/src/root/auth.tt
+++ b/src/root/auth.tt
@@ -33,7 +33,7 @@
   <div id="hydra-signin" class="modal hide fade" tabindex="-1" role="dialog" aria-hidden="true">
     <div class="modal-dialog" role="document">
       <div class="modal-content">
-        <form>
+        <form id="signin-form">
           <div class="modal-body">
             <div class="form-group">
               <label for="username" class="col-form-label">User name</label>
@@ -45,7 +45,7 @@
             </div>
           </div>
           <div class="modal-footer">
-            <button id="do-signin" type="button" class="btn btn-primary">Sign in</button>
+            <button type="submit" class="btn btn-primary">Sign in</button>
             <button type="button" class="btn btn-secondary" data-dismiss="modal">Cancel</button>
           </div>
         </form>
@@ -57,10 +57,11 @@
 
     function finishSignOut() { }
 
-    $("#do-signin").click(function() {
+    $("#signin-form").submit(function(e) {
+      e.preventDefault();
       requestJSON({
         url: "[% c.uri_for('/login') %]",
-        data: $(this).parents("form").serialize(),
+        data: $(this).serialize(),
         type: 'POST',
         success: function(data) {
           window.location.reload();