Merge branch 'master' into use-store-api

Use `LegacySSHStore`

flake.lock

@@ -1,51 +1,10 @@
 {
   "nodes": {
-    "flake-parts": {
-      "inputs": {
-        "nixpkgs-lib": [
-          "nix-eval-jobs",
-          "nixpkgs"
-        ]
-      },
-      "locked": {
-        "lastModified": 1722555600,
-        "narHash": "sha256-XOQkdLafnb/p9ij77byFQjDf5m5QYl9b2REiVClC+x4=",
-        "owner": "hercules-ci",
-        "repo": "flake-parts",
-        "rev": "8471fe90ad337a8074e957b69ca4d0089218391d",
-        "type": "github"
-      },
-      "original": {
-        "owner": "hercules-ci",
-        "repo": "flake-parts",
-        "type": "github"
-      }
-    },
-    "libgit2": {
-      "flake": false,
-      "locked": {
-        "lastModified": 1715853528,
-        "narHash": "sha256-J2rCxTecyLbbDdsyBWn9w7r3pbKRMkI9E7RvRgAqBdY=",
-        "owner": "libgit2",
-        "repo": "libgit2",
-        "rev": "36f7e21ad757a3dacc58cf7944329da6bc1d6e96",
-        "type": "github"
-      },
-      "original": {
-        "owner": "libgit2",
-        "ref": "v1.8.1",
-        "repo": "libgit2",
-        "type": "github"
-      }
-    },
     "nix": {
       "inputs": {
         "flake-compat": [],
         "flake-parts": [],
         "git-hooks-nix": [],
-        "libgit2": [
-          "libgit2"
-        ],
         "nixpkgs": [
           "nixpkgs"
         ],
@@ -53,88 +12,58 @@
         "nixpkgs-regression": []
       },
       "locked": {
-        "lastModified": 1726787955,
-        "narHash": "sha256-XFznzb8L4SdUm9u+w3DPpMWJhffuv+/6+aiVl00slns=",
+        "lastModified": 1739899400,
+        "narHash": "sha256-q/RgA4bB7zWai4oPySq9mch7qH14IEeom2P64SXdqHs=",
         "owner": "NixOS",
         "repo": "nix",
-        "rev": "a7fdef6858dd45b9d7bda7c92324c63faee7f509",
+        "rev": "e310c19a1aeb1ce1ed4d41d5ab2d02db596e0918",
         "type": "github"
       },
       "original": {
         "owner": "NixOS",
-        "ref": "2.24-maintenance",
+        "ref": "2.26-maintenance",
         "repo": "nix",
         "type": "github"
       }
     },
     "nix-eval-jobs": {
-      "inputs": {
-        "flake-parts": "flake-parts",
-        "nix-github-actions": [],
-        "nixpkgs": [
-          "nixpkgs"
-        ],
-        "treefmt-nix": "treefmt-nix"
-      },
+      "flake": false,
       "locked": {
-        "lastModified": 1733814344,
-        "narHash": "sha256-3wwtKpS5tUBdjaGeSia7CotonbiRB6K5Kp0dsUt3nzU=",
+        "lastModified": 1739500569,
+        "narHash": "sha256-3wIReAqdTALv39gkWXLMZQvHyBOc3yPkWT2ZsItxedY=",
         "owner": "nix-community",
         "repo": "nix-eval-jobs",
-        "rev": "889ea1406736b53cf165b6c28398aae3969418d1",
+        "rev": "4b392b284877d203ae262e16af269f702df036bc",
         "type": "github"
       },
       "original": {
         "owner": "nix-community",
-        "ref": "release-2.24",
         "repo": "nix-eval-jobs",
         "type": "github"
       }
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1726688310,
-        "narHash": "sha256-Xc9lEtentPCEtxc/F1e6jIZsd4MPDYv4Kugl9WtXlz0=",
+        "lastModified": 1739461644,
+        "narHash": "sha256-1o1qR0KYozYGRrnqytSpAhVBYLNBHX+Lv6I39zGRzKM=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "dbebdd67a6006bb145d98c8debf9140ac7e651d0",
+        "rev": "97a719c9f0a07923c957cf51b20b329f9fb9d43f",
         "type": "github"
       },
       "original": {
         "owner": "NixOS",
-        "ref": "nixos-24.05-small",
+        "ref": "nixos-24.11-small",
         "repo": "nixpkgs",
         "type": "github"
       }
     },
     "root": {
       "inputs": {
-        "libgit2": "libgit2",
         "nix": "nix",
         "nix-eval-jobs": "nix-eval-jobs",
         "nixpkgs": "nixpkgs"
       }
-    },
-    "treefmt-nix": {
-      "inputs": {
-        "nixpkgs": [
-          "nix-eval-jobs",
-          "nixpkgs"
-        ]
-      },
-      "locked": {
-        "lastModified": 1723303070,
-        "narHash": "sha256-krGNVA30yptyRonohQ+i9cnK+CfCpedg6z3qzqVJcTs=",
-        "owner": "numtide",
-        "repo": "treefmt-nix",
-        "rev": "14c092e0326de759e16b37535161b3cb9770cea3",
-        "type": "github"
-      },
-      "original": {
-        "owner": "numtide",
-        "repo": "treefmt-nix",
-        "type": "github"
-      }
     }
   },
   "root": "root",

flake.nix

@@ -1,25 +1,25 @@
 {
   description = "A Nix-based continuous build system";
 
-  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-24.05-small";
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-24.11-small";
 
-  inputs.libgit2 = { url = "github:libgit2/libgit2/v1.8.1"; flake = false; };
-  inputs.nix.url = "github:NixOS/nix/2.24-maintenance";
-  inputs.nix.inputs.nixpkgs.follows = "nixpkgs";
-  inputs.nix.inputs.libgit2.follows = "libgit2";
+  inputs.nix = {
+    url = "github:NixOS/nix/2.26-maintenance";
+    inputs.nixpkgs.follows = "nixpkgs";
 
-  inputs.nix-eval-jobs.url = "github:nix-community/nix-eval-jobs/release-2.24";
-  inputs.nix-eval-jobs.inputs.nixpkgs.follows = "nixpkgs";
+    # hide nix dev tooling from our lock file
+    inputs.flake-parts.follows = "";
+    inputs.git-hooks-nix.follows = "";
+    inputs.nixpkgs-regression.follows = "";
+    inputs.nixpkgs-23-11.follows = "";
+    inputs.flake-compat.follows = "";
+  };
 
-  # hide nix dev tooling from our lock file
-  inputs.nix.inputs.flake-parts.follows = "";
-  inputs.nix.inputs.git-hooks-nix.follows = "";
-  inputs.nix.inputs.nixpkgs-regression.follows = "";
-  inputs.nix.inputs.nixpkgs-23-11.follows = "";
-  inputs.nix.inputs.flake-compat.follows = "";
-
-  # hide nix-eval-jobs dev tooling from our lock file
-  inputs.nix-eval-jobs.inputs.nix-github-actions.follows = "";
+  inputs.nix-eval-jobs = {
+    url = "github:nix-community/nix-eval-jobs";
+    # We want to control the deps precisely
+    flake = false;
+  };
 
   outputs = { self, nixpkgs, nix, nix-eval-jobs, ... }:
     let
@@ -30,9 +30,9 @@
 
       # A Nixpkgs overlay that provides a 'hydra' package.
       overlays.default = final: prev: {
+        nix-eval-jobs = final.callPackage nix-eval-jobs {};
         hydra = final.callPackage ./package.nix {
           inherit (nixpkgs.lib) fileset;
-          nix-eval-jobs = nix-eval-jobs.packages.${final.system}.default;
           rawSrc = self;
           nix-perl-bindings = final.nixComponents.nix-perl-bindings;
         };
@@ -74,11 +74,20 @@
       });
 
       packages = forEachSystem (system: {
+        nix-eval-jobs = nixpkgs.legacyPackages.${system}.callPackage nix-eval-jobs {
+          nix = nix.packages.${system}.nix;
+        };
         hydra = nixpkgs.legacyPackages.${system}.callPackage ./package.nix {
           inherit (nixpkgs.lib) fileset;
-          nix-eval-jobs = nix-eval-jobs.packages.${system}.default;
+          inherit (self.packages.${system}) nix-eval-jobs;
           rawSrc = self;
-          nix = nix.packages.${system}.nix;
+          inherit (nix.packages.${system})
+            nix-util
+            nix-store
+            nix-main
+            nix-cmd
+            nix-cli
+            ;
           nix-perl-bindings = nix.hydraJobs.perlBindings.${system};
         };
         default = self.packages.${system}.hydra;

foreman/start-manual.sh

@@ -1,6 +1,6 @@
 #!/bin/sh
 
-mdbook serve \
+exec mdbook serve \
   --port 63332 \
   --dest-dir ./.hydra-data/manual \
   ./doc/manual/

meson.build

@@ -8,22 +8,22 @@ project('hydra', 'cpp',
   ],
 )
 
+nix_util_dep = dependency('nix-util', required: true)
 nix_store_dep = dependency('nix-store', required: true)
 nix_main_dep = dependency('nix-main', required: true)
-nix_expr_dep = dependency('nix-expr', required: true)
-nix_flake_dep = dependency('nix-flake', required: true)
-nix_cmd_dep = dependency('nix-cmd', required: true)
 
 # Nix need extra flags not provided in its pkg-config files.
 nix_dep = declare_dependency(
   dependencies: [
+    nix_util_dep,
     nix_store_dep,
     nix_main_dep,
-    nix_expr_dep,
-    nix_flake_dep,
-    nix_cmd_dep,
   ],
-  compile_args: ['-include', 'nix/config.h'],
+  compile_args: [
+    '-include', 'nix/config-util.hh',
+    '-include', 'nix/config-store.hh',
+    '-include', 'nix/config-main.hh',
+  ],
 )
 
 pqxx_dep = dependency('libpqxx', required: true)

package.nix

@@ -8,7 +8,11 @@
 
 , perlPackages
 
-, nix
+, nix-util
+, nix-store
+, nix-main
+, nix-cmd
+, nix-cli
 , nix-perl-bindings
 , git
 
@@ -90,7 +94,6 @@ let
         DateTime
         DBDPg
         DBDSQLite
-        DBIxClassHelpers
         DigestSHA1
         EmailMIME
         EmailSender
@@ -163,7 +166,7 @@ stdenv.mkDerivation (finalAttrs: {
     nukeReferences
     pkg-config
     mdbook
-    nix
+    nix-cli
     perlDeps
     perl
     unzip
@@ -173,7 +176,10 @@ stdenv.mkDerivation (finalAttrs: {
     libpqxx
     openssl
     libxslt
-    nix
+    nix-util
+    nix-store
+    nix-main
+    nix-cmd
     perlDeps
     perl
     boost
@@ -200,13 +206,14 @@ stdenv.mkDerivation (finalAttrs: {
     glibcLocales
     libressl.nc
     python3
+    nix-cli
   ];
 
   hydraPath = lib.makeBinPath (
     [
       subversion
       openssh
-      nix
+      nix-cli
       coreutils
       findutils
       pixz
@@ -267,7 +274,7 @@ stdenv.mkDerivation (finalAttrs: {
             --prefix PATH ':' $out/bin:$hydraPath \
             --set HYDRA_RELEASE ${version} \
             --set HYDRA_HOME $out/libexec/hydra \
-            --set NIX_RELEASE ${nix.name or "unknown"} \
+            --set NIX_RELEASE ${nix-cli.name or "unknown"} \
             --set NIX_EVAL_JOBS_RELEASE ${nix-eval-jobs.name or "unknown"}
     done
   '';
@@ -275,5 +282,5 @@ stdenv.mkDerivation (finalAttrs: {
   dontStrip = true;
 
   meta.description = "Build of Hydra on ${stdenv.system}";
-  passthru = { inherit perlDeps nix; };
+  passthru = { inherit perlDeps; };
 })

src/hydra-build-step/hydra-build-step.cc

@@ -0,0 +1,213 @@
+/* This is a helper program that performs a build step, i.e. a single
+   derivation. In addition to a derivation path, it takes three store
+   URLs as arguments:
+
+   * --store: The store that will hold the resulting store paths
+       (typically a binary cache).
+
+   * --eval-store: The store that holds the .drv files, as produced by
+       hydra-evaluator.
+
+   * --build-store: The store that performs the build (often a
+       SSHStore for remote builds).
+
+   The build log is written to the path indicated by --log-file.
+*/
+
+#include "util.hh"
+#include "shared.hh"
+#include "common-eval-args.hh"
+#include "store-api.hh"
+#include "build-result.hh"
+#include "derivations.hh"
+#include "worker-protocol.hh"
+
+#include <chrono>
+
+using namespace nix;
+
+// FIXME: cut&paste
+static std::string_view getS(const std::vector<Logger::Field> & fields, size_t n)
+{
+    assert(n < fields.size());
+    assert(fields[n].type == Logger::Field::tString);
+    return fields[n].s;
+}
+
+void mainWrapped(std::list<std::string> args)
+{
+    verbosity = lvlError;
+
+    struct MyArgs : MixEvalArgs, MixCommonArgs, RootArgs
+    {
+        Path drvPath;
+        std::optional<std::string> buildStoreUrl;
+        std::optional<Path> logPath;
+        std::optional<uint64_t> maxOutputSize;
+
+        MyArgs() : MixCommonArgs("hydra-build-step")
+        {
+            expectArg("drv-path", &drvPath);
+
+            addFlag({
+                .longName = "build-store",
+                .description = "The Nix store to use for building the derivation.",
+                //.category = category,
+                .labels = {"store-url"},
+                .handler = {&buildStoreUrl},
+            });
+
+            addFlag({
+                .longName = "log-file",
+                .description = "The path to the build log.",
+                .labels = {"path"},
+                .handler = {&logPath},
+            });
+
+            addFlag({
+                .longName = "max-output-size",
+                .description = "Maximum size of the outputs.",
+                .labels = {"bytes"},
+                .handler = {&maxOutputSize},
+            });
+        }
+    };
+
+    /* A logger that intercepts all build log lines and writes them to
+       the log file. */
+    MyArgs myArgs;
+    myArgs.parseCmdline(args);
+
+    struct MyLogger : public Logger
+    {
+        Logger & prev;
+        AutoCloseFD logFile;
+
+        MyLogger(Logger & prev, Path logPath) : prev(prev)
+        {
+            logFile = open(logPath.c_str(), O_CREAT | O_TRUNC | O_WRONLY, 0666);
+            if (!logFile)
+                throw SysError("creating log file '%s'", logPath);
+        }
+
+        void log(Verbosity lvl, std::string_view s) override
+        { prev.log(lvl, s); }
+
+        void logEI(const ErrorInfo & ei) override
+        { prev.logEI(ei); }
+
+        void writeToStdout(std::string_view s) override
+        { prev.writeToStdout(s); }
+
+        void result(ActivityId act, ResultType type, const Fields & fields) override
+        {
+            if (type == resBuildLogLine)
+                writeLine(logFile.get(), std::string(getS(fields, 0)));
+            else
+                prev.result(act, type, fields);
+        }
+    };
+
+    auto destStore = openStore();
+    auto evalStore = myArgs.evalStoreUrl ? openStore(*myArgs.evalStoreUrl) : destStore;
+    auto buildStore = myArgs.buildStoreUrl ? openStore(*myArgs.buildStoreUrl) : destStore;
+
+    auto drvPath = evalStore->parseStorePath(myArgs.drvPath);
+
+    auto drv = evalStore->readDerivation(drvPath);
+    BasicDerivation basicDrv(drv);
+
+    uint64_t overhead = 0;
+
+    /* Gather the inputs. */
+    StorePathSet inputs;
+
+    for (auto & p : drv.inputSrcs)
+        inputs.insert(p);
+
+    for (auto & [drvPath, node] : drv.inputDrvs.map) {
+        auto drv2 = evalStore->readDerivation(drvPath);
+        for (auto & name : node.value) {
+            if (auto i = get(drv2.outputs, name)) {
+                auto outPath = i->path(*evalStore, drv2.name, name);
+                inputs.insert(*outPath);
+                basicDrv.inputSrcs.insert(*outPath);
+            }
+        }
+    }
+
+    /* Ensure that the inputs exist in the destination store (so that
+       the builder can substitute them from the destination
+       store). This is a no-op for regular stores, but for the binary
+       cache store, this will copy the inputs to the binary cache from
+       the local store. */
+    {
+        auto now1 = std::chrono::steady_clock::now();
+
+        debug("sending closure of '%s' to '%s'",
+            evalStore->printStorePath(drvPath), destStore->getUri());
+
+        if (evalStore != destStore)
+            copyClosure(*evalStore, *destStore, drv.inputSrcs, NoRepair, NoCheckSigs);
+
+        copyClosure(*destStore, *buildStore, inputs, NoRepair, NoCheckSigs, Substitute);
+
+        auto now2 = std::chrono::steady_clock::now();
+
+        overhead += std::chrono::duration_cast<std::chrono::milliseconds>(now2 - now1).count();
+    }
+
+    /* Perform the build. */
+    if (myArgs.logPath)
+        logger = new MyLogger(*logger, *myArgs.logPath);
+
+    auto buildResult = buildStore->buildDerivation(drvPath, basicDrv);
+
+    /* Copy the output paths from the build store to the destination
+       store. */
+    size_t totalNarSize = 0;
+
+    if (buildResult.success()) {
+
+        std::map<StorePath, ValidPathInfo> infos;
+        StorePathSet outputs;
+        for (auto & [output, realisation] : buildResult.builtOutputs) {
+            auto info = buildStore->queryPathInfo(realisation.outPath);
+            totalNarSize += info->narSize;
+            infos.insert_or_assign(info->path, *info);
+            outputs.insert(info->path);
+        }
+
+        if ((!myArgs.maxOutputSize || totalNarSize <= *myArgs.maxOutputSize)
+            && buildStore != destStore)
+        {
+            debug("copying outputs of '%s' from '%s' (%d bytes)",
+                buildStore->printStorePath(drvPath), buildStore->getUri(), totalNarSize);
+
+            auto now1 = std::chrono::steady_clock::now();
+
+            copyPaths(*buildStore, *destStore, outputs, NoRepair, NoCheckSigs);
+
+            auto now2 = std::chrono::steady_clock::now();
+
+            overhead += std::chrono::duration_cast<std::chrono::milliseconds>(now2 - now1).count();
+        }
+    }
+
+    FdSink to { STDOUT_FILENO };
+    WorkerProto::WriteConn wconn {
+        .to = to,
+        // Hardcode latest version because we are deploying hydra
+        // itself atomically
+        .version = PROTOCOL_VERSION,
+    };
+    WorkerProto::write(*evalStore, wconn, buildResult);
+}
+
+int main(int argc, char * * argv)
+{
+    return handleExceptions(argv[0], [&]() {
+        initNix();
+        mainWrapped(argvToStrings(argc, argv));
+    });
+}

src/hydra-build-step/meson.build

@@ -0,0 +1,14 @@
+srcs = files(
+  'hydra-build-step.cc',
+)
+
+hydra_build_step = executable('hydra-build-step',
+  'hydra-build-step.cc',
+  srcs,
+  dependencies: [
+    libhydra_dep,
+    nix_dep,
+    dependency('nix-cmd', required: true)
+  ],
+  install: true,
+)

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

@@ -1,356 +1,27 @@
-#include <algorithm>
-#include <cmath>
-
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
+#include <math.h>
 
 #include "build-result.hh"
-#include "path.hh"
 #include "serve-protocol.hh"
-#include "serve-protocol-impl.hh"
 #include "state.hh"
 #include "current-process.hh"
 #include "processes.hh"
 #include "util.hh"
-#include "serve-protocol.hh"
-#include "serve-protocol-impl.hh"
-#include "ssh.hh"
 #include "finally.hh"
 #include "url.hh"
+#include "worker-protocol.hh"
 
 using namespace nix;
 
 namespace nix::build_remote {
 
-static Strings extraStoreArgs(std::string & machine)
-{
-    Strings result;
-    try {
-        auto parsed = parseURL(machine);
-        if (parsed.scheme != "ssh") {
-            throw SysError("Currently, only (legacy-)ssh stores are supported!");
-        }
-        machine = parsed.authority.value_or("");
-        auto remoteStore = parsed.query.find("remote-store");
-        if (remoteStore != parsed.query.end()) {
-            result = {"--store", shellEscape(remoteStore->second)};
-        }
-    } catch (BadURL &) {
-        // We just try to continue with `machine->sshName` here for backwards compat.
-    }
-
-    return result;
-}
-
-static std::unique_ptr<SSHMaster::Connection> openConnection(
-    ::Machine::ptr machine, SSHMaster & master)
-{
-    Strings command = {"nix-store", "--serve", "--write"};
-    if (machine->isLocalhost()) {
-        command.push_back("--builders");
-        command.push_back("");
-    } else {
-        command.splice(command.end(), extraStoreArgs(machine->sshName));
-    }
-
-    auto ret = master.startCommand(std::move(command), {
-        "-a", "-oBatchMode=yes", "-oConnectTimeout=60", "-oTCPKeepAlive=yes"
-    });
-
-    // XXX: determine the actual max value we can use from /proc.
-
-    // FIXME: Should this be upstreamed into `startCommand` in Nix?
-
-    int pipesize = 1024 * 1024;
-
-    fcntl(ret->in.get(), F_SETPIPE_SZ, &pipesize);
-    fcntl(ret->out.get(), F_SETPIPE_SZ, &pipesize);
-
-    return ret;
-}
-
-
-static void copyClosureTo(
-    ::Machine::Connection & conn,
-    Store & destStore,
-    const StorePathSet & paths,
-    SubstituteFlag useSubstitutes = NoSubstitute)
-{
-    StorePathSet closure;
-    destStore.computeFSClosure(paths, closure);
-
-    /* Send the "query valid paths" command with the "lock" option
-       enabled. This prevents a race where the remote host
-       garbage-collect paths that are already there. Optionally, ask
-       the remote host to substitute missing paths. */
-    // FIXME: substitute output pollutes our build log
-    /* Get back the set of paths that are already valid on the remote
-       host. */
-    auto present = conn.queryValidPaths(
-        destStore, true, closure, useSubstitutes);
-
-    if (present.size() == closure.size()) return;
-
-    auto sorted = destStore.topoSortPaths(closure);
-
-    StorePathSet missing;
-    for (auto i = sorted.rbegin(); i != sorted.rend(); ++i)
-        if (!present.count(*i)) missing.insert(*i);
-
-    printMsg(lvlDebug, "sending %d missing paths", missing.size());
-
-    std::unique_lock<std::timed_mutex> sendLock(conn.machine->state->sendLock,
-        std::chrono::seconds(600));
-
-    conn.to << ServeProto::Command::ImportPaths;
-    destStore.exportPaths(missing, conn.to);
-    conn.to.flush();
-
-    if (readInt(conn.from) != 1)
-        throw Error("remote machine failed to import closure");
-}
-
-
-// FIXME: use Store::topoSortPaths().
-static StorePaths reverseTopoSortPaths(const std::map<StorePath, UnkeyedValidPathInfo> & paths)
-{
-    StorePaths sorted;
-    StorePathSet visited;
-
-    std::function<void(const StorePath & path)> dfsVisit;
-
-    dfsVisit = [&](const StorePath & path) {
-        if (!visited.insert(path).second) return;
-
-        auto info = paths.find(path);
-        auto references = info == paths.end() ? StorePathSet() : info->second.references;
-
-        for (auto & i : references)
-            /* Don't traverse into paths that don't exist.  That can
-               happen due to substitutes for non-existent paths. */
-            if (i != path && paths.count(i))
-                dfsVisit(i);
-
-        sorted.push_back(path);
-    };
-
-    for (auto & i : paths)
-        dfsVisit(i.first);
-
-    return sorted;
-}
-
-static std::pair<Path, AutoCloseFD> openLogFile(const std::string & logDir, const StorePath & drvPath)
+static Path createLogFileDir(const std::string & logDir, const StorePath & drvPath)
 {
     std::string base(drvPath.to_string());
     auto logFile = logDir + "/" + std::string(base, 0, 2) + "/" + std::string(base, 2);
 
     createDirs(dirOf(logFile));
 
-    AutoCloseFD logFD = open(logFile.c_str(), O_CREAT | O_TRUNC | O_WRONLY, 0666);
-    if (!logFD) throw SysError("creating log file ‘%s’", logFile);
-
-    return {std::move(logFile), std::move(logFD)};
-}
-
-static BasicDerivation sendInputs(
-    State & state,
-    Step & step,
-    Store & localStore,
-    Store & destStore,
-    ::Machine::Connection & conn,
-    unsigned int & overhead,
-    counter & nrStepsWaiting,
-    counter & nrStepsCopyingTo
-)
-{
-    /* Replace the input derivations by their output paths to send a
-       minimal closure to the builder.
-
-       `tryResolve` currently does *not* rewrite input addresses, so it
-       is safe to do this in all cases. (It should probably have a mode
-       to do that, however, but we would not use it here.)
-     */
-    BasicDerivation basicDrv = ({
-        auto maybeBasicDrv = step.drv->tryResolve(destStore, &localStore);
-        if (!maybeBasicDrv)
-            throw Error(
-                "the derivation '%s' can’t be resolved. It’s probably "
-                "missing some outputs",
-                localStore.printStorePath(step.drvPath));
-        *maybeBasicDrv;
-    });
-
-    /* Ensure that the inputs exist in the destination store. This is
-       a no-op for regular stores, but for the binary cache store,
-       this will copy the inputs to the binary cache from the local
-       store. */
-    if (&localStore != &destStore) {
-        copyClosure(localStore, destStore,
-            step.drv->inputSrcs,
-            NoRepair, NoCheckSigs, NoSubstitute);
-    }
-
-    {
-        auto mc1 = std::make_shared<MaintainCount<counter>>(nrStepsWaiting);
-        mc1.reset();
-        MaintainCount<counter> mc2(nrStepsCopyingTo);
-
-        printMsg(lvlDebug, "sending closure of ‘%s’ to ‘%s’",
-            localStore.printStorePath(step.drvPath), conn.machine->sshName);
-
-        auto now1 = std::chrono::steady_clock::now();
-
-        /* Copy the input closure. */
-        if (conn.machine->isLocalhost()) {
-            StorePathSet closure;
-            destStore.computeFSClosure(basicDrv.inputSrcs, closure);
-            copyPaths(destStore, localStore, closure, NoRepair, NoCheckSigs, NoSubstitute);
-        } else {
-            copyClosureTo(conn, destStore, basicDrv.inputSrcs, Substitute);
-        }
-
-        auto now2 = std::chrono::steady_clock::now();
-
-        overhead += std::chrono::duration_cast<std::chrono::milliseconds>(now2 - now1).count();
-    }
-
-    return basicDrv;
-}
-
-static BuildResult performBuild(
-    ::Machine::Connection & conn,
-    Store & localStore,
-    StorePath drvPath,
-    const BasicDerivation & drv,
-    const ServeProto::BuildOptions & options,
-    counter & nrStepsBuilding
-)
-{
-    conn.putBuildDerivationRequest(localStore, drvPath, drv, options);
-
-    BuildResult result;
-
-    time_t startTime, stopTime;
-
-    startTime = time(0);
-    {
-        MaintainCount<counter> mc(nrStepsBuilding);
-        result = ServeProto::Serialise<BuildResult>::read(localStore, conn);
-    }
-    stopTime = time(0);
-
-    if (!result.startTime) {
-        // If the builder gave `startTime = 0`, use our measurements
-        // instead of the builder's.
-        //
-        // Note: this represents the duration of a single round, rather
-        // than all rounds.
-        result.startTime = startTime;
-        result.stopTime = stopTime;
-    }
-
-    // If the protocol was too old to give us `builtOutputs`, initialize
-    // it manually by introspecting the derivation.
-    if (GET_PROTOCOL_MINOR(conn.remoteVersion) < 6)
-    {
-        // If the remote is too old to handle CA derivations, we can’t get this
-        // far anyways
-        assert(drv.type().hasKnownOutputPaths());
-        DerivationOutputsAndOptPaths drvOutputs = drv.outputsAndOptPaths(localStore);
-        // Since this a `BasicDerivation`, `staticOutputHashes` will not
-        // do any real work.
-        auto outputHashes = staticOutputHashes(localStore, drv);
-        for (auto & [outputName, output] : drvOutputs) {
-            auto outputPath = output.second;
-            // We’ve just asserted that the output paths of the derivation
-            // were known
-            assert(outputPath);
-            auto outputHash = outputHashes.at(outputName);
-            auto drvOutput = DrvOutput { outputHash, outputName };
-            result.builtOutputs.insert_or_assign(
-                std::move(outputName),
-                Realisation { drvOutput, *outputPath });
-        }
-    }
-
-    return result;
-}
-
-static std::map<StorePath, UnkeyedValidPathInfo> queryPathInfos(
-    ::Machine::Connection & conn,
-    Store & localStore,
-    StorePathSet & outputs,
-    size_t & totalNarSize
-)
-{
-
-    /* Get info about each output path. */
-    std::map<StorePath, UnkeyedValidPathInfo> infos;
-    conn.to << ServeProto::Command::QueryPathInfos;
-    ServeProto::write(localStore, conn, outputs);
-    conn.to.flush();
-    while (true) {
-        auto storePathS = readString(conn.from);
-        if (storePathS == "") break;
-
-        auto storePath = localStore.parseStorePath(storePathS);
-        auto info = ServeProto::Serialise<UnkeyedValidPathInfo>::read(localStore, conn);
-        totalNarSize += info.narSize;
-        infos.insert_or_assign(std::move(storePath), std::move(info));
-    }
-
-    return infos;
-}
-
-static void copyPathFromRemote(
-    ::Machine::Connection & conn,
-    NarMemberDatas & narMembers,
-    Store & localStore,
-    Store & destStore,
-    const ValidPathInfo & info
-)
-{
-      /* Receive the NAR from the remote and add it to the
-          destination store. Meanwhile, extract all the info from the
-          NAR that getBuildOutput() needs. */
-      auto source2 = sinkToSource([&](Sink & sink)
-      {
-          /* Note: we should only send the command to dump the store
-              path to the remote if the NAR is actually going to get read
-              by the destination store, which won't happen if this path
-              is already valid on the destination store. Since this
-              lambda function only gets executed if someone tries to read
-              from source2, we will send the command from here rather
-              than outside the lambda. */
-          conn.to << ServeProto::Command::DumpStorePath << localStore.printStorePath(info.path);
-          conn.to.flush();
-
-          TeeSource tee(conn.from, sink);
-          extractNarData(tee, localStore.printStorePath(info.path), narMembers);
-      });
-
-      destStore.addToStore(info, *source2, NoRepair, NoCheckSigs);
-}
-
-static void copyPathsFromRemote(
-    ::Machine::Connection & conn,
-    NarMemberDatas & narMembers,
-    Store & localStore,
-    Store & destStore,
-    const std::map<StorePath, UnkeyedValidPathInfo> & infos
-)
-{
-      auto pathsSorted = reverseTopoSortPaths(infos);
-
-      for (auto & path : pathsSorted) {
-          auto & info = infos.find(path)->second;
-          copyPathFromRemote(
-              conn, narMembers, localStore, destStore,
-              ValidPathInfo { path, info });
-      }
-
+    return logFile;
 }
 
 }
@@ -359,11 +30,14 @@ static void copyPathsFromRemote(
 
 void RemoteResult::updateWithBuildResult(const nix::BuildResult & buildResult)
 {
-    startTime = buildResult.startTime;
-    stopTime = buildResult.stopTime;
+    // FIXME: make RemoteResult inherit BuildResult.
     timesBuilt = buildResult.timesBuilt;
     errorMsg = buildResult.errorMsg;
     isNonDeterministic = buildResult.isNonDeterministic;
+    if (buildResult.startTime && buildResult.stopTime) {
+        startTime = buildResult.startTime;
+        stopTime = buildResult.stopTime;
+    }
 
     switch ((BuildResult::Status) buildResult.status) {
         case BuildResult::Built:
@@ -412,19 +86,8 @@ void RemoteResult::updateWithBuildResult(const nix::BuildResult & buildResult)
 
 }
 
-/* Utility guard object to auto-release a semaphore on destruction. */
-template <typename T>
-class SemaphoreReleaser {
-public:
-    SemaphoreReleaser(T* s) : sem(s) {}
-    ~SemaphoreReleaser() { sem->release(); }
-
-private:
-    T* sem;
-};
 
 void State::buildRemote(ref<Store> destStore,
-    MachineReservation::ptr & reservation,
     ::Machine::ptr machine, Step::ptr step,
     const ServeProto::BuildOptions & buildOptions,
     RemoteResult & result, std::shared_ptr<ActiveStep> activeStep,
@@ -433,30 +96,44 @@ void State::buildRemote(ref<Store> destStore,
 {
     assert(BuildResult::TimedOut == 8);
 
-    auto [logFile, logFD] = build_remote::openLogFile(logDir, step->drvPath);
-    AutoDelete logFileDel(logFile, false);
-    result.logFile = logFile;
+    result.logFile = build_remote::createLogFileDir(logDir, step->drvPath);
 
     try {
 
-        updateStep(ssConnecting);
+        updateStep(ssBuilding);
+        result.startTime = time(0);
 
-        SSHMaster master {
-            machine->sshName,
-            machine->sshKey,
-            machine->sshPublicHostKey,
-            false, // no SSH master yet
-            false, // no compression yet
-            logFD.get(),
+        auto buildStoreUrl = machine->completeStoreReference().render();
+
+        Strings args = {
+            localStore->printStorePath(step->drvPath),
+            "--store", destStore->getUri(),
+            "--eval-store", localStore->getUri(),
+            "--build-store", buildStoreUrl,
+            "--max-silent-time", std::to_string(buildOptions.maxSilentTime),
+            "--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.nrRepeats),
+            "--log-file", result.logFile,
+            // FIXME: step->isDeterministic
         };
 
-        // FIXME: rewrite to use Store.
-        auto child = build_remote::openConnection(machine, master);
+        // FIXME: set pid for cancellation
 
+        auto [status, childStdout] = [&]() {
+            MaintainCount<counter> mc(nrStepsBuilding);
+            return runProgram({
+                .program = "hydra-build-step",
+                .args = std::move(args),
+            });
+        }();
+
+        #if 0
         {
             auto activeStepState(activeStep->state_.lock());
             if (activeStepState->cancelled) throw Error("step cancelled");
-            activeStepState->pid = child->sshPid;
+            activeStepState->pid = conn.store->getConnectionPid();
         }
 
         Finally clearPid([&]() {
@@ -470,82 +147,32 @@ void State::buildRemote(ref<Store> destStore,
                possibility that we end up killing another
                process. Meh. */
         });
+        #endif
 
-        ::Machine::Connection conn {
-            {
-                .to = child->in.get(),
-                .from = child->out.get(),
-                /* Handshake. */
-                .remoteVersion = 0xdadbeef, // FIXME avoid dummy initialize
-            },
-            /*.machine =*/ machine,
-        };
+        result.stopTime = time(0);
 
-        Finally updateStats([&]() {
-            bytesReceived += conn.from.read;
-            bytesSent += conn.to.written;
-        });
-
-        constexpr ServeProto::Version our_version = 0x206;
-
-        try {
-            conn.remoteVersion = decltype(conn)::handshake(
-                conn.to,
-                conn.from,
-                our_version,
-                machine->sshName);
-        } catch (EndOfFile & e) {
-            child->sshPid.wait();
-            std::string s = chomp(readFile(result.logFile));
-            throw Error("cannot connect to ‘%1%’: %2%", machine->sshName, s);
-        }
-
-        // Do not attempt to speak a newer version of the protocol.
-        //
-        // Per https://github.com/NixOS/nix/issues/9584 should be handled as
-        // part of `handshake` in upstream nix.
-        conn.remoteVersion = std::min(conn.remoteVersion, our_version);
+        if (!statusOk(status))
+            throw ExecError(status, fmt("hydra-build-step %s with output:\n%s", statusToString(status), stdout));
 
+        /* The build was executed successfully, so clear the failure
+           count for this machine. */
         {
             auto info(machine->state->connectInfo.lock());
             info->consecutiveFailures = 0;
         }
 
-        /* Gather the inputs. If the remote side is Nix <= 1.9, we have to
-           copy the entire closure of ‘drvPath’, as well as the required
-           outputs of the input derivations. On Nix > 1.9, we only need to
-           copy the immediate sources of the derivation and the required
-           outputs of the input derivations. */
-        updateStep(ssSendingInputs);
-        BasicDerivation resolvedDrv = build_remote::sendInputs(*this, *step, *localStore, *destStore, conn, result.overhead, nrStepsWaiting, nrStepsCopyingTo);
+        StringSource from { childStdout };
+        /* Read the BuildResult from the child. */
+        WorkerProto::ReadConn rconn {
+            .from = from,
+            // Hardcode latest version because we are deploying hydra
+            // itself atomically
+            .version = PROTOCOL_VERSION,
+        };
+        result.overhead += readNum<uint64_t>(rconn.from);
+        auto totalNarSize = readNum<uint64_t>(rconn.from);
+        auto buildResult = WorkerProto::Serialise<BuildResult>::read(*localStore, rconn);
 
-        logFileDel.cancel();
-
-        /* Truncate the log to get rid of messages about substitutions
-            etc. on the remote system. */
-        if (lseek(logFD.get(), SEEK_SET, 0) != 0)
-            throw SysError("seeking to the start of log file ‘%s’", result.logFile);
-
-        if (ftruncate(logFD.get(), 0) == -1)
-            throw SysError("truncating log file ‘%s’", result.logFile);
-
-        logFD = -1;
-
-        /* Do the build. */
-        printMsg(lvlDebug, "building ‘%s’ on ‘%s’",
-            localStore->printStorePath(step->drvPath),
-            machine->sshName);
-
-        updateStep(ssBuilding);
-
-        BuildResult buildResult = build_remote::performBuild(
-            conn,
-            *localStore,
-            step->drvPath,
-            resolvedDrv,
-            buildOptions,
-            nrStepsBuilding
-        );
 
         result.updateWithBuildResult(buildResult);
 
@@ -553,82 +180,22 @@ void State::buildRemote(ref<Store> destStore,
 
         result.errorMsg = "";
 
+        /* If the NAR size limit was exceeded, then hydra-build-step
+           will not have copied the output paths. */
+        if (totalNarSize > maxOutputSize) {
+            result.stepStatus = bsNarSizeLimitExceeded;
+            return;
+        }
+
         /* If the path was substituted or already valid, then we didn't
            get a build log. */
         if (result.isCached) {
             printMsg(lvlInfo, "outputs of ‘%s’ substituted or already valid on ‘%s’",
-                localStore->printStorePath(step->drvPath), machine->sshName);
+                localStore->printStorePath(step->drvPath), machine->storeUri.render());
             unlink(result.logFile.c_str());
             result.logFile = "";
         }
 
-        /* Throttle CPU-bound work. Opportunistically skip updating the current
-         * step, since this requires a DB roundtrip. */
-        if (!localWorkThrottler.try_acquire()) {
-            MaintainCount<counter> mc(nrStepsWaitingForDownloadSlot);
-            updateStep(ssWaitingForLocalSlot);
-            localWorkThrottler.acquire();
-        }
-        SemaphoreReleaser releaser(&localWorkThrottler);
-
-        /* Once we've started copying outputs, release the machine reservation
-         * so further builds can happen. We do not release the machine earlier
-         * to avoid situations where the queue runner is bottlenecked on
-         * copying outputs and we end up building too many things that we
-         * haven't been able to allow copy slots for. */
-        assert(reservation.unique());
-        reservation = 0;
-        wakeDispatcher();
-
-        StorePathSet outputs;
-        for (auto & [_, realisation] : buildResult.builtOutputs)
-            outputs.insert(realisation.outPath);
-
-        /* Copy the output paths. */
-        if (!machine->isLocalhost() || localStore != std::shared_ptr<Store>(destStore)) {
-            updateStep(ssReceivingOutputs);
-
-            MaintainCount<counter> mc(nrStepsCopyingFrom);
-
-            auto now1 = std::chrono::steady_clock::now();
-
-            size_t totalNarSize = 0;
-            auto infos = build_remote::queryPathInfos(conn, *localStore, outputs, totalNarSize);
-
-            if (totalNarSize > maxOutputSize) {
-                result.stepStatus = bsNarSizeLimitExceeded;
-                return;
-            }
-
-            /* Copy each path. */
-            printMsg(lvlDebug, "copying outputs of ‘%s’ from ‘%s’ (%d bytes)",
-                localStore->printStorePath(step->drvPath), machine->sshName, totalNarSize);
-
-            build_remote::copyPathsFromRemote(conn, narMembers, *localStore, *destStore, infos);
-            auto now2 = std::chrono::steady_clock::now();
-
-            result.overhead += std::chrono::duration_cast<std::chrono::milliseconds>(now2 - now1).count();
-        }
-
-        /* Register the outputs of the newly built drv */
-        if (experimentalFeatureSettings.isEnabled(Xp::CaDerivations)) {
-            auto outputHashes = staticOutputHashes(*localStore, *step->drv);
-            for (auto & [outputName, realisation] : buildResult.builtOutputs) {
-                // Register the resolved drv output
-                destStore->registerDrvOutput(realisation);
-
-                // Also register the unresolved one
-                auto unresolvedRealisation = realisation;
-                unresolvedRealisation.signatures.clear();
-                unresolvedRealisation.id.drvHash = outputHashes.at(outputName);
-                destStore->registerDrvOutput(unresolvedRealisation);
-            }
-        }
-
-        /* Shut down the connection. */
-        child->in = -1;
-        child->sshPid.wait();
-
     } catch (Error & e) {
         /* Disable this machine until a certain period of time has
            passed. This period increases on every consecutive
@@ -641,7 +208,7 @@ void State::buildRemote(ref<Store> destStore,
             info->consecutiveFailures = std::min(info->consecutiveFailures + 1, (unsigned int) 4);
             info->lastFailure = now;
             int delta = retryInterval * std::pow(retryBackoff, info->consecutiveFailures - 1) + (rand() % 30);
-            printMsg(lvlInfo, "will disable machine ‘%1%’ for %2%s", machine->sshName, delta);
+            printMsg(lvlInfo, "will disable machine ‘%1%’ for %2%s", machine->storeUri.render(), delta);
             info->disabledUntil = now + std::chrono::seconds(delta);
         }
         throw;

src/hydra-queue-runner/builder.cc

@@ -3,6 +3,7 @@
 #include "state.hh"
 #include "hydra-build-result.hh"
 #include "finally.hh"
+#include "terminal.hh"
 #include "binary-cache-store.hh"
 
 using namespace nix;
@@ -37,22 +38,19 @@ void State::builder(MachineReservation::ptr reservation)
 
         try {
             auto destStore = getDestStore();
-            // Might release the reservation.
             res = doBuildStep(destStore, reservation, activeStep);
         } catch (std::exception & e) {
             printMsg(lvlError, "uncaught exception building ‘%s’ on ‘%s’: %s",
-                localStore->printStorePath(activeStep->step->drvPath),
-                reservation ? reservation->machine->sshName : std::string("(no machine)"),
+                localStore->printStorePath(reservation->step->drvPath),
+                reservation->machine->storeUri.render(),
                 e.what());
         }
     }
 
-    /* If the machine hasn't been released yet, release and wake up the dispatcher. */
-    if (reservation) {
-        assert(reservation.unique());
-        reservation = 0;
-        wakeDispatcher();
-    }
+    /* Release the machine and wake up the dispatcher. */
+    assert(reservation.unique());
+    reservation = 0;
+    wakeDispatcher();
 
     /* If there was a temporary failure, retry the step after an
        exponentially increasing interval. */
@@ -75,11 +73,11 @@ void State::builder(MachineReservation::ptr reservation)
 
 
 State::StepResult State::doBuildStep(nix::ref<Store> destStore,
-    MachineReservation::ptr & reservation,
+    MachineReservation::ptr reservation,
     std::shared_ptr<ActiveStep> activeStep)
 {
-    auto step(reservation->step);
-    auto machine(reservation->machine);
+    auto & step(reservation->step);
+    auto & machine(reservation->machine);
 
     {
         auto step_(step->state.lock());
@@ -153,7 +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.nrRepeats + 1, machine->sshName, buildId, (dependents.size() - 1));
+            localStore->printStorePath(step->drvPath), buildOptions.nrRepeats + 1, machine->storeUri.render(), buildId, (dependents.size() - 1));
     }
 
     if (!buildOneDone)
@@ -181,7 +179,7 @@ State::StepResult State::doBuildStep(nix::ref<Store> destStore,
                     unlink(result.logFile.c_str());
                 }
             } catch (...) {
-                ignoreException();
+                ignoreExceptionInDestructor();
             }
         }
     });
@@ -199,7 +197,7 @@ State::StepResult State::doBuildStep(nix::ref<Store> destStore,
         {
             auto mc = startDbUpdate();
             pqxx::work txn(*conn);
-            stepNr = createBuildStep(txn, result.startTime, buildId, step, machine->sshName, bsBusy);
+            stepNr = createBuildStep(txn, result.startTime, buildId, step, machine->storeUri.render(), bsBusy);
             txn.commit();
         }
 
@@ -214,7 +212,7 @@ State::StepResult State::doBuildStep(nix::ref<Store> destStore,
 
         try {
             /* FIXME: referring builds may have conflicting timeouts. */
-            buildRemote(destStore, reservation, machine, step, buildOptions, 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);
@@ -222,7 +220,7 @@ State::StepResult State::doBuildStep(nix::ref<Store> destStore,
                 result.canRetry = false;
             } else {
                 result.stepStatus = bsAborted;
-                result.errorMsg = e.msg();
+                result.errorMsg = filterANSIEscapes(e.msg(), true);
                 result.canRetry = true;
             }
         }
@@ -256,7 +254,7 @@ State::StepResult State::doBuildStep(nix::ref<Store> destStore,
     /* Finish the step in the database. */
     if (stepNr) {
         pqxx::work txn(*conn);
-        finishBuildStep(txn, result, buildId, stepNr, machine->sshName);
+        finishBuildStep(txn, result, buildId, stepNr, machine->storeUri.render());
         txn.commit();
     }
 
@@ -264,7 +262,7 @@ State::StepResult State::doBuildStep(nix::ref<Store> destStore,
        issue). Retry a number of times. */
     if (result.canRetry) {
         printMsg(lvlError, "possibly transient failure building ‘%s’ on ‘%s’: %s",
-            localStore->printStorePath(step->drvPath), machine->sshName, result.errorMsg);
+            localStore->printStorePath(step->drvPath), machine->storeUri.render(), result.errorMsg);
         assert(stepNr);
         bool retry;
         {
@@ -455,7 +453,7 @@ void State::failStep(
                     build->finishedInDB)
                     continue;
                 createBuildStep(txn,
-                    0, build->id, step, machine ? machine->sshName : "",
+                    0, build->id, step, machine ? machine->storeUri.render() : "",
                     result.stepStatus, result.errorMsg, buildId == build->id ? 0 : buildId);
             }
 

src/hydra-queue-runner/dispatcher.cc

@@ -40,15 +40,13 @@ void State::dispatcher()
             printMsg(lvlDebug, "dispatcher woken up");
             nrDispatcherWakeups++;
 
-            auto t_before_work = std::chrono::steady_clock::now();
+            auto now1 = std::chrono::steady_clock::now();
 
             auto sleepUntil = doDispatch();
 
-            auto t_after_work = std::chrono::steady_clock::now();
+            auto now2 = std::chrono::steady_clock::now();
 
-            prom.dispatcher_time_spent_running.Increment(
-                std::chrono::duration_cast<std::chrono::microseconds>(t_after_work - t_before_work).count());
-            dispatchTimeMs += std::chrono::duration_cast<std::chrono::milliseconds>(t_after_work - t_before_work).count();
+            dispatchTimeMs += std::chrono::duration_cast<std::chrono::milliseconds>(now2 - now1).count();
 
             /* Sleep until we're woken up (either because a runnable build
                is added, or because a build finishes). */
@@ -62,10 +60,6 @@ void State::dispatcher()
                 *dispatcherWakeup_ = false;
             }
 
-            auto t_after_sleep = std::chrono::steady_clock::now();
-            prom.dispatcher_time_spent_waiting.Increment(
-                std::chrono::duration_cast<std::chrono::microseconds>(t_after_sleep - t_after_work).count());
-
         } catch (std::exception & e) {
             printError("dispatcher: %s", e.what());
             sleep(1);
@@ -262,7 +256,7 @@ system_time State::doDispatch()
                 /* Can this machine do this step? */
                 if (!mi.machine->supportsStep(step)) {
                     debug("machine '%s' does not support step '%s' (system type '%s')",
-                        mi.machine->sshName, localStore->printStorePath(step->drvPath), step->drv->platform);
+                        mi.machine->storeUri.render(), localStore->printStorePath(step->drvPath), step->drv->platform);
                     continue;
                 }
 

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

@@ -70,31 +70,10 @@ State::PromMetrics::PromMetrics()
             .Register(*registry)
             .Add({})
     )
-    , dispatcher_time_spent_running(
-        prometheus::BuildCounter()
-            .Name("hydraqueuerunner_dispatcher_time_spent_running")
-            .Help("Time (in micros) spent running the dispatcher")
-            .Register(*registry)
-            .Add({})
-    )
-    , dispatcher_time_spent_waiting(
-        prometheus::BuildCounter()
-            .Name("hydraqueuerunner_dispatcher_time_spent_waiting")
-            .Help("Time (in micros) spent waiting for the dispatcher to obtain work")
-            .Register(*registry)
-            .Add({})
-    )
-    , queue_monitor_time_spent_running(
-        prometheus::BuildCounter()
-            .Name("hydraqueuerunner_queue_monitor_time_spent_running")
-            .Help("Time (in micros) spent running the queue monitor")
-            .Register(*registry)
-            .Add({})
-    )
-    , queue_monitor_time_spent_waiting(
-        prometheus::BuildCounter()
-            .Name("hydraqueuerunner_queue_monitor_time_spent_waiting")
-            .Help("Time (in micros) spent waiting for the queue monitor to obtain work")
+    , queue_max_id(
+        prometheus::BuildGauge()
+            .Name("hydraqueuerunner_queue_max_build_id_info")
+            .Help("Maximum build record ID in the queue")
             .Register(*registry)
             .Add({})
     )
@@ -106,7 +85,6 @@ State::State(std::optional<std::string> metricsAddrOpt)
     : config(std::make_unique<HydraConfig>())
     , maxUnsupportedTime(config->getIntOption("max_unsupported_time", 0))
     , dbPool(config->getIntOption("max_db_connections", 128))
-    , localWorkThrottler(config->getIntOption("max_local_worker_threads", std::min(maxSupportedLocalWorkers, std::max(4u, std::thread::hardware_concurrency()) - 2)))
     , 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))
@@ -157,65 +135,26 @@ void State::parseMachines(const std::string & contents)
         oldMachines = *machines_;
     }
 
-    for (auto line : tokenizeString<Strings>(contents, "\n")) {
-        line = trim(std::string(line, 0, line.find('#')));
-        auto tokens = tokenizeString<std::vector<std::string>>(line);
-        if (tokens.size() < 3) continue;
-        tokens.resize(8);
-
-        if (tokens[5] == "-") tokens[5] = "";
-        auto supportedFeatures = tokenizeString<StringSet>(tokens[5], ",");
-
-        if (tokens[6] == "-") tokens[6] = "";
-        auto mandatoryFeatures = tokenizeString<StringSet>(tokens[6], ",");
-
-        for (auto & f : mandatoryFeatures)
-            supportedFeatures.insert(f);
-
-        using MaxJobs = std::remove_const<decltype(nix::Machine::maxJobs)>::type;
-
-        auto machine = std::make_shared<::Machine>(nix::Machine {
-            // `storeUri`, not yet used
-            "",
-            // `systemTypes`
-            tokenizeString<StringSet>(tokens[1], ","),
-            // `sshKey`
-            tokens[2] == "-" ? "" : tokens[2],
-            // `maxJobs`
-            tokens[3] != ""
-                ? string2Int<MaxJobs>(tokens[3]).value()
-                : 1,
-            // `speedFactor`
-            std::stof(tokens[4].c_str()),
-            // `supportedFeatures`
-            std::move(supportedFeatures),
-            // `mandatoryFeatures`
-            std::move(mandatoryFeatures),
-            // `sshPublicHostKey`
-            tokens[7] != "" && tokens[7] != "-"
-                ? tokens[7]
-                : "",
-        });
-
-        machine->sshName = tokens[0];
+    for (auto && machine_ : nix::Machine::parseConfig({}, contents)) {
+        auto machine = std::make_shared<::Machine>(std::move(machine_));
 
         /* Re-use the State object of the previous machine with the
            same name. */
-        auto i = oldMachines.find(machine->sshName);
+        auto i = oldMachines.find(machine->storeUri.variant);
         if (i == oldMachines.end())
-            printMsg(lvlChatty, "adding new machine ‘%1%’", machine->sshName);
+            printMsg(lvlChatty, "adding new machine ‘%1%’", machine->storeUri.render());
         else
-            printMsg(lvlChatty, "updating machine ‘%1%’", machine->sshName);
+            printMsg(lvlChatty, "updating machine ‘%1%’", machine->storeUri.render());
         machine->state = i == oldMachines.end()
             ? std::make_shared<::Machine::State>()
             : i->second->state;
-        newMachines[machine->sshName] = machine;
+        newMachines[machine->storeUri.variant] = machine;
     }
 
     for (auto & m : oldMachines)
         if (newMachines.find(m.first) == newMachines.end()) {
             if (m.second->enabled)
-                printInfo("removing machine ‘%1%’", m.first);
+                printInfo("removing machine ‘%1%’", m.second->storeUri.render());
             /* Add a disabled ::Machine object to make sure stats are
                maintained. */
             auto machine = std::make_shared<::Machine>(*(m.second));
@@ -611,13 +550,11 @@ void State::dumpStatus(Connection & conn)
         {"nrQueuedBuilds", builds.lock()->size()},
         {"nrActiveSteps", activeSteps_.lock()->size()},
         {"nrStepsBuilding", nrStepsBuilding.load()},
+        #if 0
         {"nrStepsCopyingTo", nrStepsCopyingTo.load()},
-        {"nrStepsWaitingForDownloadSlot", nrStepsWaitingForDownloadSlot.load()},
         {"nrStepsCopyingFrom", nrStepsCopyingFrom.load()},
-        {"nrStepsWaiting", nrStepsWaiting.load()},
+        #endif
         {"nrUnsupportedSteps", nrUnsupportedSteps.load()},
-        {"bytesSent", bytesSent.load()},
-        {"bytesReceived", bytesReceived.load()},
         {"nrBuildsRead", nrBuildsRead.load()},
         {"buildReadTimeMs", buildReadTimeMs.load()},
         {"buildReadTimeAvgMs", nrBuildsRead == 0 ? 0.0 : (float) buildReadTimeMs / nrBuildsRead},
@@ -680,7 +617,7 @@ void State::dumpStatus(Connection & conn)
                     machine["avgStepTime"] = (float) s->totalStepTime / s->nrStepsDone;
                     machine["avgStepBuildTime"] = (float) s->totalStepBuildTime / s->nrStepsDone;
                 }
-                statusJson["machines"][m->sshName] = machine;
+                statusJson["machines"][m->storeUri.render()] = machine;
             }
         }
 

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

@@ -1,7 +1,6 @@
 #include "state.hh"
 #include "hydra-build-result.hh"
 #include "globals.hh"
-#include "thread-pool.hh"
 
 #include <cstring>
 
@@ -38,21 +37,16 @@ void State::queueMonitorLoop(Connection & conn)
 
     auto destStore = getDestStore();
 
+    unsigned int lastBuildId = 0;
+
     bool quit = false;
     while (!quit) {
-        auto t_before_work = std::chrono::steady_clock::now();
-
         localStore->clearPathInfoCache();
 
-        bool done = getQueuedBuilds(conn, destStore);
+        bool done = getQueuedBuilds(conn, destStore, lastBuildId);
 
         if (buildOne && buildOneDone) quit = true;
 
-        auto t_after_work = std::chrono::steady_clock::now();
-
-        prom.queue_monitor_time_spent_running.Increment(
-            std::chrono::duration_cast<std::chrono::microseconds>(t_after_work - t_before_work).count());
-
         /* Sleep until we get notification from the database about an
            event. */
         if (done && !quit) {
@@ -62,10 +56,12 @@ void State::queueMonitorLoop(Connection & conn)
             conn.get_notifs();
 
         if (auto lowestId = buildsAdded.get()) {
+            lastBuildId = std::min(lastBuildId, static_cast<unsigned>(std::stoul(*lowestId) - 1));
             printMsg(lvlTalkative, "got notification: new builds added to the queue");
         }
         if (buildsRestarted.get()) {
             printMsg(lvlTalkative, "got notification: builds restarted");
+            lastBuildId = 0; // check all builds
         }
         if (buildsCancelled.get() || buildsDeleted.get() || buildsBumped.get()) {
             printMsg(lvlTalkative, "got notification: builds cancelled or bumped");
@@ -75,10 +71,6 @@ void State::queueMonitorLoop(Connection & conn)
             printMsg(lvlTalkative, "got notification: jobset shares changed");
             processJobsetSharesChange(conn);
         }
-
-        auto t_after_sleep = std::chrono::steady_clock::now();
-        prom.queue_monitor_time_spent_waiting.Increment(
-            std::chrono::duration_cast<std::chrono::microseconds>(t_after_sleep - t_after_work).count());
     }
 
     exit(0);
@@ -92,18 +84,20 @@ struct PreviousFailure : public std::exception {
 
 
 bool State::getQueuedBuilds(Connection & conn,
-    ref<Store> destStore)
+    ref<Store> destStore, unsigned int & lastBuildId)
 {
     prom.queue_checks_started.Increment();
 
-    printInfo("checking the queue for builds...");
+    printInfo("checking the queue for builds > %d...", lastBuildId);
 
     /* Grab the queued builds from the database, but don't process
        them yet (since we don't want a long-running transaction). */
     std::vector<BuildID> newIDs;
-    std::unordered_map<BuildID, Build::ptr> newBuildsByID;
+    std::map<BuildID, Build::ptr> newBuildsByID;
     std::multimap<StorePath, BuildID> newBuildsByPath;
 
+    unsigned int newLastBuildId = lastBuildId;
+
     {
         pqxx::work txn(conn);
 
@@ -112,12 +106,17 @@ bool State::getQueuedBuilds(Connection & conn,
              "jobsets.name as jobset, job, drvPath, maxsilent, timeout, timestamp, "
              "globalPriority, priority from Builds "
              "inner join jobsets on builds.jobset_id = jobsets.id "
-             "where finished = 0 order by globalPriority desc, random()");
+             "where builds.id > $1 and finished = 0 order by globalPriority desc, builds.id",
+            lastBuildId);
 
         for (auto const & row : res) {
             auto builds_(builds.lock());
             BuildID id = row["id"].as<BuildID>();
             if (buildOne && id != buildOne) continue;
+            if (id > newLastBuildId) {
+                newLastBuildId = id;
+                prom.queue_max_id.Set(id);
+            }
             if (builds_->count(id)) continue;
 
             auto build = std::make_shared<Build>(
@@ -319,13 +318,15 @@ bool State::getQueuedBuilds(Connection & conn,
 
         /* Stop after a certain time to allow priority bumps to be
            processed. */
-        if (std::chrono::system_clock::now() > start + std::chrono::seconds(60)) {
+        if (std::chrono::system_clock::now() > start + std::chrono::seconds(600)) {
             prom.queue_checks_early_exits.Increment();
             break;
         }
     }
 
     prom.queue_checks_finished.Increment();
+
+    lastBuildId = newBuildsByID.empty() ? newLastBuildId : newBuildsByID.begin()->first - 1;
     return newBuildsByID.empty();
 }
 
@@ -404,34 +405,6 @@ void State::processQueueChange(Connection & conn)
 }
 
 
-std::map<DrvOutput, std::optional<StorePath>> State::getMissingRemotePaths(
-    ref<Store> destStore,
-    const std::map<DrvOutput, std::optional<StorePath>> & paths)
-{
-    Sync<std::map<DrvOutput, std::optional<StorePath>>> missing_;
-    ThreadPool tp;
-
-    for (auto & [output, maybeOutputPath] : paths) {
-        if (!maybeOutputPath) {
-            auto missing(missing_.lock());
-            missing->insert({output, maybeOutputPath});
-        } else {
-            tp.enqueue([&] {
-                if (!destStore->isValidPath(*maybeOutputPath)) {
-                    auto missing(missing_.lock());
-                    missing->insert({output, maybeOutputPath});
-                }
-            });
-        }
-    }
-
-    tp.process();
-
-    auto missing(missing_.lock());
-    return *missing;
-}
-
-
 Step::ptr State::createStep(ref<Store> destStore,
     Connection & conn, Build::ptr build, const StorePath & drvPath,
     Build::ptr referringBuild, Step::ptr referringStep, std::set<StorePath> & finishedDrvs,
@@ -512,15 +485,16 @@ Step::ptr State::createStep(ref<Store> destStore,
 
     /* Are all outputs valid? */
     auto outputHashes = staticOutputHashes(*localStore, *(step->drv));
-    std::map<DrvOutput, std::optional<StorePath>> paths;
+    bool valid = true;
+    std::map<DrvOutput, std::optional<StorePath>> missing;
     for (auto & [outputName, maybeOutputPath] : destStore->queryPartialDerivationOutputMap(drvPath, &*localStore)) {
         auto outputHash = outputHashes.at(outputName);
-        paths.insert({{outputHash, outputName}, maybeOutputPath});
+        if (maybeOutputPath && destStore->isValidPath(*maybeOutputPath))
+            continue;
+        valid = false;
+        missing.insert({{outputHash, outputName}, maybeOutputPath});
     }
 
-    auto missing = getMissingRemotePaths(destStore, paths);
-    bool valid = missing.empty();
-
     /* Try to copy the missing paths from the local store or from
        substitutes. */
     if (!missing.empty()) {

src/hydra-queue-runner/state.hh

@@ -6,8 +6,6 @@
 #include <map>
 #include <memory>
 #include <queue>
-#include <regex>
-#include <semaphore>
 
 #include <prometheus/counter.h>
 #include <prometheus/gauge.h>
@@ -23,8 +21,6 @@
 #include "sync.hh"
 #include "nar-extractor.hh"
 #include "serve-protocol.hh"
-#include "serve-protocol-impl.hh"
-#include "serve-protocol-connection.hh"
 #include "machines.hh"
 
 
@@ -59,7 +55,6 @@ typedef enum {
     ssConnecting = 10,
     ssSendingInputs = 20,
     ssBuilding = 30,
-    ssWaitingForLocalSlot = 35,
     ssReceivingOutputs = 40,
     ssPostProcessing = 50,
 } StepState;
@@ -243,10 +238,6 @@ struct Machine : nix::Machine
 {
     typedef std::shared_ptr<Machine> ptr;
 
-    /* TODO Get rid of: `nix::Machine::storeUri` is normalized in a way
-       we are not yet used to, but once we are, we don't need this. */
-    std::string sshName;
-
     struct State {
         typedef std::shared_ptr<State> ptr;
         counter currentJobs{0};
@@ -296,17 +287,7 @@ struct Machine : nix::Machine
         return true;
     }
 
-    bool isLocalhost()
-    {
-        std::regex r("^(ssh://|ssh-ng://)?localhost$");
-        return std::regex_search(sshName, r);
-    }
-
-    // A connection to a machine
-    struct Connection : nix::ServeProto::BasicClientConnection {
-        // Backpointer to the machine
-        ptr machine;
-    };
+    bool isLocalhost() const;
 };
 
 
@@ -360,13 +341,9 @@ private:
 
     /* The build machines. */
     std::mutex machinesReadyLock;
-    typedef std::map<std::string, Machine::ptr> Machines;
+    typedef std::map<nix::StoreReference::Variant, Machine::ptr> Machines;
     nix::Sync<Machines> machines; // FIXME: use atomic_shared_ptr
 
-    /* Throttler for CPU-bound local work. */
-    static constexpr unsigned int maxSupportedLocalWorkers = 1024;
-    std::counting_semaphore<maxSupportedLocalWorkers> localWorkThrottler;
-
     /* Various stats. */
     time_t startedAt;
     counter nrBuildsRead{0};
@@ -375,10 +352,10 @@ private:
     counter nrStepsStarted{0};
     counter nrStepsDone{0};
     counter nrStepsBuilding{0};
+    #if 0
     counter nrStepsCopyingTo{0};
-    counter nrStepsWaitingForDownloadSlot{0};
     counter nrStepsCopyingFrom{0};
-    counter nrStepsWaiting{0};
+    #endif
     counter nrUnsupportedSteps{0};
     counter nrRetries{0};
     counter maxNrRetries{0};
@@ -387,8 +364,6 @@ private:
     counter nrQueueWakeups{0};
     counter nrDispatcherWakeups{0};
     counter dispatchTimeMs{0};
-    counter bytesSent{0};
-    counter bytesReceived{0};
     counter nrActiveDbUpdates{0};
 
     /* Specific build to do for --build-one (testing only). */
@@ -465,12 +440,7 @@ private:
         prometheus::Counter& queue_steps_created;
         prometheus::Counter& queue_checks_early_exits;
         prometheus::Counter& queue_checks_finished;
-
-        prometheus::Counter& dispatcher_time_spent_running;
-        prometheus::Counter& dispatcher_time_spent_waiting;
-
-        prometheus::Counter& queue_monitor_time_spent_running;
-        prometheus::Counter& queue_monitor_time_spent_waiting;
+        prometheus::Gauge& queue_max_id;
 
         PromMetrics();
     };
@@ -514,7 +484,8 @@ private:
     void queueMonitorLoop(Connection & conn);
 
     /* Check the queue for new builds. */
-    bool getQueuedBuilds(Connection & conn, nix::ref<nix::Store> destStore);
+    bool getQueuedBuilds(Connection & conn,
+        nix::ref<nix::Store> destStore, unsigned int & lastBuildId);
 
     /* Handle cancellation, deletion and priority bumps. */
     void processQueueChange(Connection & conn);
@@ -522,12 +493,6 @@ private:
     BuildOutput getBuildOutputCached(Connection & conn, nix::ref<nix::Store> destStore,
         const nix::StorePath & drvPath);
 
-    /* Returns paths missing from the remote store. Paths are processed in
-     * parallel to work around the possible latency of remote stores. */
-    std::map<nix::DrvOutput, std::optional<nix::StorePath>> getMissingRemotePaths(
-        nix::ref<nix::Store> destStore,
-        const std::map<nix::DrvOutput, std::optional<nix::StorePath>> & paths);
-
     Step::ptr createStep(nix::ref<nix::Store> store,
         Connection & conn, Build::ptr build, const nix::StorePath & drvPath,
         Build::ptr referringBuild, Step::ptr referringStep, std::set<nix::StorePath> & finishedDrvs,
@@ -563,11 +528,10 @@ private:
        retried. */
     enum StepResult { sDone, sRetry, sMaybeCancelled };
     StepResult doBuildStep(nix::ref<nix::Store> destStore,
-        MachineReservation::ptr & reservation,
+        MachineReservation::ptr reservation,
         std::shared_ptr<ActiveStep> activeStep);
 
     void buildRemote(nix::ref<nix::Store> destStore,
-        MachineReservation::ptr & reservation,
         Machine::ptr machine, Step::ptr step,
         const nix::ServeProto::BuildOptions & buildOptions,
         RemoteResult & result, std::shared_ptr<ActiveStep> activeStep,

src/lib/Hydra/Controller/Build.pm

@@ -238,7 +238,7 @@ sub serveFile {
         # XSS hole.
         $c->response->header('Content-Security-Policy' => 'sandbox allow-scripts');
 
-        $c->stash->{'plain'} = { data => readIntoSocket(cmd => ["nix", "--experimental-features", "nix-command",
+        $c->stash->{'plain'} = { data => grab(cmd => ["nix", "--experimental-features", "nix-command",
                                                       "store", "cat", "--store", getStoreUri(), "$path"]) };
 
         # Detect MIME type.

src/lib/Hydra/Controller/Jobset.pm

@@ -364,21 +364,6 @@ sub evals_GET {
     );
 }
 
-sub errors :Chained('jobsetChain') :PathPart('errors') :Args(0) :ActionClass('REST') { }
-
-sub errors_GET {
-    my ($self, $c) = @_;
-
-    $c->stash->{template} = 'eval-error.tt';
-
-    my $jobsetName = $c->stash->{params}->{name};
-    $c->stash->{jobset} = $c->stash->{project}->jobsets->find(
-        { name => $jobsetName },
-        { '+columns' => { 'errormsg' => 'errormsg' } }
-    );
-
-    $self->status_ok($c, entity => $c->stash->{jobset});
-}
 
 # Redirect to the latest finished evaluation of this jobset.
 sub latest_eval : Chained('jobsetChain') PathPart('latest-eval') {

src/lib/Hydra/Controller/JobsetEval.pm

@@ -86,17 +86,6 @@ sub view_GET {
     );
 }
 
-sub errors :Chained('evalChain') :PathPart('errors') :Args(0) :ActionClass('REST') { }
-
-sub errors_GET {
-    my ($self, $c) = @_;
-
-    $c->stash->{template} = 'eval-error.tt';
-
-    $c->stash->{eval} = $c->model('DB::JobsetEvals')->find($c->stash->{eval}->id, { prefetch => 'evaluationerror' });
-
-    $self->status_ok($c, entity => $c->stash->{eval});
-}
 
 sub create_jobset : Chained('evalChain') PathPart('create-jobset') Args(0) {
     my ($self, $c) = @_;

src/lib/Hydra/Controller/Root.pm

@@ -162,7 +162,7 @@ sub status_GET {
             { "buildsteps.busy" => { '!=', 0 } },
             { order_by => ["globalpriority DESC", "id"],
               join => "buildsteps",
-              columns => [@buildListColumns, 'buildsteps.drvpath', 'buildsteps.type']
+              columns => [@buildListColumns]
             })]
     );
 }

src/lib/Hydra/Helper/BuildDiff.pm

@@ -37,16 +37,7 @@ sub buildDiff {
 
     my $n = 0;
     foreach my $build (@{$builds}) {
-        my $aborted = $build->finished != 0 && (
-            # aborted
-            $build->buildstatus == 3
-            # cancelled
-            || $build->buildstatus == 4
-            # timeout
-            || $build->buildstatus == 7
-            # log limit exceeded
-            || $build->buildstatus == 10
-        );
+        my $aborted = $build->finished != 0 && ($build->buildstatus == 3 || $build->buildstatus == 4);
         my $d;
         my $found = 0;
         while ($n < scalar(@{$builds2})) {
@@ -88,4 +79,4 @@ sub buildDiff {
     return $ret;
 }
 
-1;
+1;

src/lib/Hydra/Helper/Nix.pm

@@ -36,7 +36,6 @@ our @EXPORT = qw(
     jobsetOverview
     jobsetOverview_
     pathIsInsidePrefix
-    readIntoSocket
     readNixFile
     registerRoot
     restartBuilds
@@ -297,7 +296,8 @@ sub getEvals {
 
     my @evals = $evals_result_set->search(
         { hasnewbuilds => 1 },
-        { order_by => "$me.id DESC", rows => $rows, offset => $offset });
+        { order_by => "$me.id DESC", rows => $rows, offset => $offset
+        , prefetch => { evaluationerror => [ ] } });
     my @res = ();
     my $cache = {};
 
@@ -417,16 +417,6 @@ sub pathIsInsidePrefix {
     return $cur;
 }
 
-sub readIntoSocket{
-    my (%args) = @_;
-    my $sock;
-
-    eval {
-        open($sock, "-|", @{$args{cmd}}) or die q(failed to open socket from command:\n $x);
-    };
-
-    return $sock;
-}
 
 
 

src/lib/Hydra/Schema/Result/EvaluationErrors.pm

@@ -105,6 +105,4 @@ __PACKAGE__->add_column(
     "+id" => { retrieve_on_insert => 1 }
 );
 
-__PACKAGE__->mk_group_accessors('column' => 'has_error');
-
 1;

src/lib/Hydra/Schema/Result/Jobsets.pm

@@ -386,8 +386,6 @@ __PACKAGE__->add_column(
     "+id" => { retrieve_on_insert => 1 }
 );
 
-__PACKAGE__->mk_group_accessors('column' => 'has_error');
-
 sub supportsDynamicRunCommand {
   my ($self) = @_;
 

src/lib/Hydra/Schema/ResultSet/EvaluationErrors.pm

@@ -1,30 +0,0 @@
-package Hydra::Schema::ResultSet::EvaluationErrors;
-
-use strict;
-use utf8;
-use warnings;
-
-use parent 'DBIx::Class::ResultSet';
-
-use Storable qw(dclone);
-
-__PACKAGE__->load_components('Helper::ResultSet::RemoveColumns');
-
-# Exclude expensive error message values unless explicitly requested, and
-# replace them with a summary field describing their presence/absence.
-sub search_rs {
-  my ( $class, $query, $attrs ) = @_;
-
-  if ($attrs) {
-    $attrs = dclone($attrs);
-  }
-
-  unless (exists $attrs->{'select'} || exists $attrs->{'columns'}) {
-    $attrs->{'+columns'}->{'has_error'} = "errormsg != ''";
-  }
-  unless (exists $attrs->{'+columns'}->{'errormsg'}) {
-    push @{ $attrs->{'remove_columns'} }, 'errormsg';
-  }
-
-  return $class->next::method($query, $attrs);
-}

src/lib/Hydra/Schema/ResultSet/Jobsets.pm

@@ -1,30 +0,0 @@
-package Hydra::Schema::ResultSet::Jobsets;
-
-use strict;
-use utf8;
-use warnings;
-
-use parent 'DBIx::Class::ResultSet';
-
-use Storable qw(dclone);
-
-__PACKAGE__->load_components('Helper::ResultSet::RemoveColumns');
-
-# Exclude expensive error message values unless explicitly requested, and
-# replace them with a summary field describing their presence/absence.
-sub search_rs {
-  my ( $class, $query, $attrs ) = @_;
-
-  if ($attrs) {
-    $attrs = dclone($attrs);
-  }
-
-  unless (exists $attrs->{'select'} || exists $attrs->{'columns'}) {
-    $attrs->{'+columns'}->{'has_error'} = "errormsg != ''";
-  }
-  unless (exists $attrs->{'+columns'}->{'errormsg'}) {
-    push @{ $attrs->{'remove_columns'} }, 'errormsg';
-  }
-
-  return $class->next::method($query, $attrs);
-}

src/meson.build

@@ -1,5 +1,6 @@
 # Native code
 subdir('libhydra')
+subdir('hydra-build-step')
 subdir('hydra-evaluator')
 subdir('hydra-queue-runner')
 

src/root/build.tt

@@ -61,7 +61,21 @@ END;
             <td>[% IF step.busy != 0 || ((step.machine || step.starttime) && (step.status == 0 || step.status == 1 || step.status == 3 || step.status == 4 || step.status == 7)); INCLUDE renderMachineName machine=step.machine; ELSE; "<em>n/a</em>"; END %]</td>
             <td class="step-status">
               [% IF step.busy != 0 %]
-                [% INCLUDE renderBusyStatus %]
+                [% IF step.busy == 1 %]
+                  <strong>Preparing</strong>
+                [% ELSIF step.busy == 10 %]
+                  <strong>Connecting</strong>
+                [% ELSIF step.busy == 20 %]
+                  <strong>Sending inputs</strong>
+                [% ELSIF step.busy == 30 %]
+                  <strong>Building</strong>
+                [% ELSIF step.busy == 40 %]
+                  <strong>Receiving outputs</strong>
+                [% ELSIF step.busy == 50 %]
+                  <strong>Post-processing</strong>
+                [% ELSE %]
+                  <strong>Unknown state</strong>
+                [% END %]
               [% ELSIF step.status == 0 %]
                 [% IF step.isnondeterministic %]
                   <span class="warn">Succeeded with non-determistic result</span>

src/root/common.tt

@@ -91,17 +91,6 @@ BLOCK renderDuration;
   duration % 60 %]s[%
 END;
 
-BLOCK renderDrvInfo;
-  drvname = step.drvpath
-    .substr(11) # strip `/nix/store/`
-    .split('-').slice(1).join("-") # strip hash part
-    .substr(0, -4); # strip `.drv`
-  IF drvname != releasename;
-    IF step.type == 0; action = "Build"; ELSE; action = "Substitution"; END;
-    IF drvname; %]<em> ([% action %] of [% drvname %])</em>[% END;
-  END;
-END;
-
 
 BLOCK renderBuildListHeader %]
   <table class="table table-striped table-condensed clickable-rows">
@@ -142,12 +131,7 @@ BLOCK renderBuildListBody;
       [% END %]
       <td><a class="row-link" href="[% link %]">[% build.id %]</a></td>
       [% IF !hideJobName %]
-        <td>
-          <a href="[%link%]">[% IF !hideJobsetName %][%build.jobset.get_column("project")%]:[%build.jobset.get_column("name")%]:[% END %][%build.get_column("job")%]</a>
-          [% IF showStepName %]
-            [% INCLUDE renderDrvInfo step=build.buildsteps releasename=build.nixname %]
-          [% END %]
-        </td>
+        <td><a href="[%link%]">[% IF !hideJobsetName %][%build.jobset.get_column("project")%]:[%build.jobset.get_column("name")%]:[% END %][%build.get_column("job")%]</td>
       [% END %]
       <td class="nowrap">[% t = showSchedulingInfo ? build.timestamp : build.stoptime; IF t; INCLUDE renderRelativeDate timestamp=(showSchedulingInfo ? build.timestamp : build.stoptime); ELSE; "-"; END %]</td>
       <td>[% !showSchedulingInfo and build.get_column('releasename') ? build.get_column('releasename') : build.nixname %]</td>
@@ -261,27 +245,6 @@ BLOCK renderBuildStatusIcon;
 END;
 
 
-BLOCK renderBusyStatus;
-  IF step.busy == 1 %]
-    <strong>Preparing</strong>
-  [% ELSIF step.busy == 10 %]
-    <strong>Connecting</strong>
-  [% ELSIF step.busy == 20 %]
-    <strong>Sending inputs</strong>
-  [% ELSIF step.busy == 30 %]
-    <strong>Building</strong>
-  [% ELSIF step.busy == 35 %]
-    <strong>Waiting to receive outputs</strong>
-  [% ELSIF step.busy == 40 %]
-    <strong>Receiving outputs</strong>
-  [% ELSIF step.busy == 50 %]
-    <strong>Post-processing</strong>
-  [% ELSE %]
-    <strong>Unknown state</strong>
-  [% END;
-END;
-
-
 BLOCK renderStatus;
   IF build.finished;
     buildstatus = build.buildstatus;
@@ -513,7 +476,7 @@ BLOCK renderEvals %]
             ELSE %]
              -
             [% END %]
-            [% IF eval.evaluationerror.has_error %]
+            [% IF eval.evaluationerror.errormsg %]
               <span class="badge badge-warning">Eval Errors</span>
             [% END %]
           </td>
@@ -639,7 +602,7 @@ BLOCK renderJobsetOverview %]
         <td>[% HTML.escape(j.description) %]</td>
         <td>[% IF j.lastcheckedtime;
                  INCLUDE renderDateTime timestamp = j.lastcheckedtime;
-                 IF j.has_error || j.fetcherrormsg; %]&nbsp;<span class = 'badge badge-warning'>Error</span>[% END;
+                 IF j.errormsg || j.fetcherrormsg; %]&nbsp;<span class = 'badge badge-warning'>Error</span>[% END;
                  ELSE; "-";
                END %]</td>
         [% IF j.get_column('nrtotal') > 0 %]

src/root/eval-error.tt

@@ -1,26 +0,0 @@
-[% PROCESS common.tt %]
-<!DOCTYPE html>
-
-<html lang="en">
-
-  <head>
-    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
-    <meta http-equiv="X-UA-Compatible" content="IE=Edge" />
-    [% INCLUDE style.tt %]
-  </head>
-
-  <body>
-
-    <div class="tab-content tab-pane">
-        <div id="tabs-errors" class="">
-          [% IF jobset %]
-              <p>Errors occurred at [% INCLUDE renderDateTime timestamp=(jobset.errortime || jobset.lastcheckedtime) %].</p>
-              <div class="card bg-light"><div class="card-body"><pre>[% HTML.escape(jobset.fetcherrormsg || jobset.errormsg) %]</pre></div></div>
-          [% ELSIF eval %]
-              <p>Errors occurred at [% INCLUDE renderDateTime timestamp=(eval.evaluationerror.errortime || eval.timestamp) %].</p>
-              <div class="card bg-light"><div class="card-body"><pre>[% HTML.escape(eval.evaluationerror.errormsg) %]</pre></div></div>
-          [% END %]
-        </div>
-    </div>
-  </body>
-</html>

src/root/jobset-eval.tt

@@ -65,7 +65,7 @@ c.uri_for(c.controller('JobsetEval').action_for('view'),
   [% END %]
 
   [% IF aborted.size > 0 %]
-    <li class="nav-item"><a class="nav-link" href="#tabs-aborted" data-toggle="tab"><span class="text-warning">Aborted / Timed out Jobs ([% aborted.size %])</span></a></li>
+    <li class="nav-item"><a class="nav-link" href="#tabs-aborted" data-toggle="tab"><span class="text-warning">Aborted Jobs ([% aborted.size %])</span></a></li>
   [% END %]
   [% IF nowFail.size > 0 %]
     <li class="nav-item"><a class="nav-link" href="#tabs-now-fail" data-toggle="tab"><span class="text-warning">Newly Failing Jobs ([% nowFail.size %])</span></a></li>
@@ -90,7 +90,7 @@ c.uri_for(c.controller('JobsetEval').action_for('view'),
   [% END %]
   <li class="nav-item"><a class="nav-link" href="#tabs-inputs" data-toggle="tab">Inputs</a></li>
 
-  [% IF eval.evaluationerror.has_error %]
+  [% IF eval.evaluationerror.errormsg %]
     <li class="nav-item"><a class="nav-link" href="#tabs-errors" data-toggle="tab"><span class="text-warning">Evaluation Errors</span></a></li>
   [% END %]
 </ul>
@@ -108,6 +108,13 @@ c.uri_for(c.controller('JobsetEval').action_for('view'),
 
 <div class="tab-content">
 
+  [% IF eval.evaluationerror.errormsg %]
+    <div id="tabs-errors" class="tab-pane">
+      <p>Errors occurred at [% INCLUDE renderDateTime timestamp=(eval.evaluationerror.errortime || eval.timestamp) %].</p>
+      <div class="card bg-light"><div class="card-body"><pre>[% HTML.escape(eval.evaluationerror.errormsg) %]</pre></div></div>
+    </div>
+  [% END %]
+
   <div id="tabs-aborted" class="tab-pane">
     [% INCLUDE renderSome builds=aborted tabname="#tabs-aborted" %]
   </div>
@@ -165,9 +172,10 @@ c.uri_for(c.controller('JobsetEval').action_for('view'),
     [% END %]
   </div>
 
-  [% IF eval.evaluationerror.has_error %]
+  [% IF eval.evaluationerror.errormsg %]
     <div id="tabs-errors" class="tab-pane">
-      <iframe src="[% c.uri_for(c.controller('JobsetEval').action_for('errors'), [eval.id], params) %]" loading="lazy" frameBorder="0" width="100%"></iframe>
+      <p>Errors occurred at [% INCLUDE renderDateTime timestamp=(eval.evaluationerror.errortime || eval.timestamp) %].</p>
+      <div class="card bg-light"><div class="card-body"><pre>[% HTML.escape(eval.evaluationerror.errormsg) %]</pre></div></div>
     </div>
   [% END %]
 </div>

src/root/jobset.tt

@@ -61,7 +61,7 @@
   [% END %]
 
   <li class="nav-item"><a class="nav-link active" href="#tabs-evaluations" data-toggle="tab">Evaluations</a></li>
-  [% IF jobset.has_error || jobset.fetcherrormsg %]
+  [% IF jobset.errormsg || jobset.fetcherrormsg %]
     <li class="nav-item"><a class="nav-link" href="#tabs-errors" data-toggle="tab"><span class="text-warning">Evaluation Errors</span></a></li>
   [% END %]
   <li class="nav-item"><a class="nav-link" href="#tabs-jobs" data-toggle="tab">Jobs</a></li>
@@ -79,7 +79,7 @@
         <th>Last checked:</th>
         <td>
           [% IF jobset.lastcheckedtime %]
-            [% INCLUDE renderDateTime timestamp = jobset.lastcheckedtime %], [% IF jobset.has_error || jobset.fetcherrormsg %]<em class="text-warning">with errors!</em>[% ELSE %]<em>no errors</em>[% END %]
+            [% INCLUDE renderDateTime timestamp = jobset.lastcheckedtime %], [% IF jobset.errormsg || jobset.fetcherrormsg %]<em class="text-warning">with errors!</em>[% ELSE %]<em>no errors</em>[% END %]
           [% ELSE %]
             <em>never</em>
           [% END %]
@@ -117,9 +117,10 @@
 
   </div>
 
-  [% IF jobset.has_error || jobset.fetcherrormsg %]
+  [% IF jobset.errormsg || jobset.fetcherrormsg %]
     <div id="tabs-errors" class="tab-pane">
-      <iframe src="[% c.uri_for('/jobset' project.name jobset.name "errors") %]" loading="lazy" frameBorder="0" width="100%"></iframe>
+      <p>Errors occurred at [% INCLUDE renderDateTime timestamp=(jobset.errortime || jobset.lastcheckedtime) %].</p>
+      <div class="card bg-light"><div class="card-body"><pre>[% HTML.escape(jobset.fetcherrormsg || jobset.errormsg) %]</pre></div></div>
     </div>
   [% END %]
 

src/root/layout.tt

@@ -10,7 +10,31 @@
 
     <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
     <meta http-equiv="X-UA-Compatible" content="IE=Edge" />
-    [% INCLUDE style.tt %]
+
+    <script type="text/javascript" src="[% c.uri_for("/static/js/jquery/jquery-3.4.1.min.js") %]"></script>
+    <script type="text/javascript" src="[% c.uri_for("/static/js/jquery/jquery-ui-1.10.4.min.js") %]"></script>
+    <script type="text/javascript" src="[% c.uri_for("/static/js/moment/moment-2.24.0.min.js") %]"></script>
+
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+
+    <link href="[% c.uri_for("/static/fontawesome/css/all.css") %]" rel="stylesheet" />
+    <script type="text/javascript" src="[% c.uri_for("/static/js/popper.min.js") %]"></script>
+    <script type="text/javascript" src="[% c.uri_for("/static/bootstrap/js/bootstrap.min.js") %]"></script>
+    <link href="[% c.uri_for("/static/bootstrap/css/bootstrap.min.css") %]" rel="stylesheet" />
+
+    <!-- hydra.css may need to be moved to before boostrap to make the @media rule work. -->
+    <link rel="stylesheet" href="[% c.uri_for("/static/css/hydra.css") %]" type="text/css" />
+    <link rel="stylesheet" href="[% c.uri_for("/static/css/rotated-th.css") %]" type="text/css" />
+
+    <style>
+      .popover { max-width: 40%; }
+    </style>
+
+    <script type="text/javascript" src="[% c.uri_for("/static/js/bootbox.min.js") %]"></script>
+
+    <link rel="stylesheet" href="[% c.uri_for("/static/css/tree.css") %]" type="text/css" />
+
+    <script type="text/javascript" src="[% c.uri_for("/static/js/common.js") %]"></script>
 
     [% IF c.config.enable_google_login %]
       <meta name="google-signin-client_id" content="[% c.config.google_client_id %]">

src/root/machine-status.tt

@@ -6,10 +6,10 @@
   <thead>
     <tr>
       <th>Job</th>
+      <th>System</th>
       <th>Build</th>
       <th>Step</th>
       <th>What</th>
-      <th>Status</th>
       <th>Since</th>
     </tr>
   </thead>
@@ -40,10 +40,10 @@
           [% idle = 0 %]
           <tr>
             <td><tt>[% INCLUDE renderFullJobName project=step.project jobset=step.jobset job=step.job %]</tt></td>
+            <td><tt>[% step.system %]</tt></td>
             <td><a href="[% c.uri_for('/build' step.build) %]">[% step.build %]</a></td>
             <td>[% IF step.busy >= 30 %]<a class="row-link" href="[% c.uri_for('/build' step.build 'nixlog' step.stepnr 'tail') %]">[% step.stepnr %]</a>[% ELSE; step.stepnr; END %]</td>
             <td><tt>[% step.drvpath.match('-(.*)').0 %]</tt></td>
-            <td>[% INCLUDE renderBusyStatus %]</td>
             <td style="width: 10em">[% INCLUDE renderDuration duration = curTime - step.starttime %] </td>
           </tr>
         [% END %]

src/root/static/js/common.js

@@ -129,12 +129,6 @@ $(document).ready(function() {
             el.addClass("is-local");
         }
     });
-
-    [...document.getElementsByTagName("iframe")].forEach((element) => {
-        element.contentWindow.addEventListener("DOMContentLoaded", (_) => {
-            element.style.height = element.contentWindow.document.body.scrollHeight + 'px';
-        })
-    })
 });
 
 var tabsLoaded = {};

src/root/status.tt

@@ -7,7 +7,7 @@
 
 [% ELSE %]
 
-  [% INCLUDE renderBuildList builds=resource showSchedulingInfo=1 hideResultInfo=1 busy=1 showStepName=1 %]
+  [% INCLUDE renderBuildList builds=resource showSchedulingInfo=1 hideResultInfo=1 busy=1 %]
 
 [% END %]
 

src/root/style.tt

@@ -1,24 +0,0 @@
-<script type="text/javascript" src="[% c.uri_for("/static/js/jquery/jquery-3.4.1.min.js") %]"></script>
-<script type="text/javascript" src="[% c.uri_for("/static/js/jquery/jquery-ui-1.10.4.min.js") %]"></script>
-<script type="text/javascript" src="[% c.uri_for("/static/js/moment/moment-2.24.0.min.js") %]"></script>
-
-<meta name="viewport" content="width=device-width, initial-scale=1.0" />
-
-<link href="[% c.uri_for("/static/fontawesome/css/all.css") %]" rel="stylesheet" />
-<script type="text/javascript" src="[% c.uri_for("/static/js/popper.min.js") %]"></script>
-<script type="text/javascript" src="[% c.uri_for("/static/bootstrap/js/bootstrap.min.js") %]"></script>
-<link href="[% c.uri_for("/static/bootstrap/css/bootstrap.min.css") %]" rel="stylesheet" />
-
-<!-- hydra.css may need to be moved to before boostrap to make the @media rule work. -->
-<link rel="stylesheet" href="[% c.uri_for("/static/css/hydra.css") %]" type="text/css" />
-<link rel="stylesheet" href="[% c.uri_for("/static/css/rotated-th.css") %]" type="text/css" />
-
-<style>
-  .popover { max-width: 40%; }
-</style>
-
-<script type="text/javascript" src="[% c.uri_for("/static/js/bootbox.min.js") %]"></script>
-
-<link rel="stylesheet" href="[% c.uri_for("/static/css/tree.css") %]" type="text/css" />
-
-<script type="text/javascript" src="[% c.uri_for("/static/js/common.js") %]"></script>

t/Hydra/Controller/Jobset/evals.t

@@ -32,9 +32,4 @@ subtest "/jobset/PROJECT/JOBSET/evals" => sub {
     ok($jobsetevals->is_success, "The page showing the jobset evals returns 200.");
 };
 
-subtest "/jobset/PROJECT/JOBSET/errors" => sub {
-    my $jobsetevals = request(GET '/jobset/' . $project->name . '/' . $jobset->name . '/errors');
-    ok($jobsetevals->is_success, "The page showing the jobset eval errors returns 200.");
-};
-
 done_testing;

t/Hydra/Controller/JobsetEval/fetch.t

@@ -35,10 +35,6 @@ subtest "Fetching the eval's overview" => sub {
     is($fetch->code, 200, "channel page is 200");
 };
 
-subtest "Fetching the eval's overview" => sub {
-    my $fetch = request(GET '/eval/' . $eval->id, '/errors');
-    is($fetch->code, 200, "errors page is 200");
-};
 
 
 done_testing;

t/lib/CliRunners.pm

@@ -14,7 +14,7 @@ our @EXPORT = qw(
 sub evalSucceeds {
     my ($jobset) = @_;
     my ($res, $stdout, $stderr) = captureStdoutStderr(60, ("hydra-eval-jobset", $jobset->project->name, $jobset->name));
-    $jobset->discard_changes({ '+columns' => {'errormsg' => 'errormsg'} });  # refresh from DB
+    $jobset->discard_changes;  # refresh from DB
     if ($res) {
         chomp $stdout; chomp $stderr;
         utf8::decode($stdout) or die "Invalid unicode in stdout.";
@@ -29,7 +29,7 @@ sub evalSucceeds {
 sub evalFails {
     my ($jobset) = @_;
     my ($res, $stdout, $stderr) = captureStdoutStderr(60, ("hydra-eval-jobset", $jobset->project->name, $jobset->name));
-    $jobset->discard_changes({ '+columns' => {'errormsg' => 'errormsg'} });  # refresh from DB
+    $jobset->discard_changes;  # refresh from DB
     if (!$res) {
         chomp $stdout; chomp $stderr;
         utf8::decode($stdout) or die "Invalid unicode in stdout.";

t/meson.build

@@ -27,6 +27,8 @@ testenv.prepend('PERL5LIB',
   separator: ':'
 )
 testenv.prepend('PATH',
+  fs.parent(find_program('nix').full_path()),
+  fs.parent(hydra_build_step.full_path()),
   fs.parent(hydra_evaluator.full_path()),
   fs.parent(hydra_queue_runner.full_path()),
   meson.project_source_root() / 'src/script',

t/queue-runner/direct-indirect-constituents.t

@@ -13,7 +13,7 @@ my $constituentBuildA = $builds->{"constituentA"};
 my $constituentBuildB = $builds->{"constituentB"};
 
 my $eval = $constituentBuildA->jobsetevals->first();
-is($eval->evaluationerror->has_error, 0);
+is($eval->evaluationerror->errormsg, "");
 
 subtest "Verifying the direct aggregate" => sub {
     my $aggBuild = $builds->{"direct_aggregate"};