fix(xvm): an asset the payload does not ship is not placed, not a refused install (2026.10.9.2)

.github/workflows/xlings-ci-linux.yml

@@ -340,7 +340,7 @@ jobs:
           echo "XDEV=$xdev" >> "$GITHUB_ENV"
           export XDEV_BIN="$xdev"
           mkdir -p target/xdev/linux-xdev
-          printf '%s\n' '{"name":"linux-xdev","platform":"linux","probes":{}}' > target/xdev/linux-xdev/lane.json
+          printf '{"name":"linux-xdev","platform":"linux","run":"%s:%s","probes":{}}\n' "$GITHUB_RUN_ID" "$GITHUB_RUN_ATTEMPT" > target/xdev/linux-xdev/lane.json
           XTEST_META_OUT="$GITHUB_WORKSPACE/target/xdev/linux-xdev/meta.ndjson" \
           XTEST_RESULTS_OUT="$GITHUB_WORKSPACE/target/xdev/linux-xdev/cases.ndjson" \
             mcpp test -p xdev
@@ -826,7 +826,7 @@ jobs:
           $dir = "target/xdev/windows-wsl"
           New-Item -ItemType Directory -Force $dir | Out-Null
           $name = "wsl: subos export --tar imports with wsl --import (WSL1)"
-          '{"name":"windows-wsl","platform":"windows","probes":{}}' | Set-Content "$dir/lane.json"
+          ('{"name":"windows-wsl","platform":"windows","run":"' + $env:GITHUB_RUN_ID + ':' + $env:GITHUB_RUN_ATTEMPT + '","probes":{}}') | Set-Content "$dir/lane.json"
           ('{"test":"' + $name + '","area":"scenario","covers":["EXPORT-WSL"],"requires":[],"proves":"flow"}') | Set-Content "$dir/meta.ndjson"
           if ("${{ steps.run.outcome }}" -eq "success") { $st = "pass"; $msg = "" }
           elseif ("${{ steps.setup.outcome }}" -ne "success") { $st = "skip"; $msg = "WSL1 could not be set up on this runner" }

.github/workflows/xlings-ci-macos.yml

@@ -290,7 +290,7 @@ jobs:
           xdev="$GITHUB_WORKSPACE/$xdev"
           export XDEV_BIN="$xdev"
           mkdir -p target/xdev/macos-xdev
-          printf '%s\n' '{"name":"macos-xdev","platform":"macosx","probes":{}}' > target/xdev/macos-xdev/lane.json
+          printf '{"name":"macos-xdev","platform":"macos","run":"%s:%s","probes":{}}\n' "$GITHUB_RUN_ID" "$GITHUB_RUN_ATTEMPT" > target/xdev/macos-xdev/lane.json
           XTEST_META_OUT="$GITHUB_WORKSPACE/target/xdev/macos-xdev/meta.ndjson" \
           XTEST_RESULTS_OUT="$GITHUB_WORKSPACE/target/xdev/macos-xdev/cases.ndjson" \
             mcpp test -p xdev

.github/workflows/xlings-ci-windows.yml

@@ -288,7 +288,7 @@ jobs:
           if (-not $xdev) { Write-Host "::error::mcpp build -p xdev produced no xdev.exe under target/"; exit 1 }
           $env:XDEV_BIN = $xdev.FullName
           New-Item -ItemType Directory -Force target/xdev/windows-xdev | Out-Null
-          '{"name":"windows-xdev","platform":"windows","probes":{}}' | Set-Content target/xdev/windows-xdev/lane.json
+          ('{"name":"windows-xdev","platform":"windows","run":"' + $env:GITHUB_RUN_ID + ':' + $env:GITHUB_RUN_ATTEMPT + '","probes":{}}') | Set-Content target/xdev/windows-xdev/lane.json
           $env:XTEST_META_OUT = "$env:GITHUB_WORKSPACE/target/xdev/windows-xdev/meta.ndjson"
           $env:XTEST_RESULTS_OUT = "$env:GITHUB_WORKSPACE/target/xdev/windows-xdev/cases.ndjson"
           mcpp test -p xdev

apps/xdev/src/main.cpp

@@ -696,11 +696,15 @@ int cmd_report_dirs(const std::vector<fs::path>& dirs, bool summary,
             lanes.push_back(l);
         }
         const auto first = records.size();
-        std::string execution = fs::absolute(dir).lexically_normal().string();
+        // A trend sample needs the execution it came from. A lane that does
+        // not say (a hand-written lane.json) is reported but never sampled:
+        // its directory names the same place in every CI run, so it would read
+        // as one execution with two results.
+        std::string execution;
         std::string platform;
         if (!lanes.empty() && lanes.back().value("name", "") == lane_name) {
             platform = lanes.back().value("platform", "");
-            execution = lanes.back().value("run", execution);
+            execution = lanes.back().value("run", "");
         }
         for (auto& j : read_ndjson(dir / "mcpp.ndjson")) {
             if (!j.contains("test")) continue;
@@ -735,7 +739,7 @@ int cmd_report_dirs(const std::vector<fs::path>& dirs, bool summary,
             if (!program.empty()) j["test"] = program + ":" + name;
             meta[{lane_name, j.value("test", "")}] = j;
         }
-        if (!platform.empty())
+        if (!platform.empty() && !execution.empty())
             for (auto i = first; i < records.size(); ++i) {
                 const auto& r = records[i];
                 observations.push_back({r.kind, r.name, platform, lane_name, execution, r.status, r.ms});

apps/xdev/tests/test_cli.cpp

@@ -232,6 +232,21 @@ XTEST(XdevCli, TrendArtifactsPreserveMemberAndPlatformAndFeedFutureShardPlans,
         "--trend", (failure / "trend.json").string(), "--write", (fixture.home.root() / "repeat").string()});
     EXPECT_EQ(duplicate.exit_code, 1);
     EXPECT_EQ(json::parse(tk::read_file(fixture.home.root() / "repeat/trend.json"))["observations"].size(), 3);
+    // A lane that does not name its execution is reported, never sampled:
+    // its directory is the same in every CI run.
+    const auto unnamed = fixture.home.root() / "input-unnamed";
+    tk::write_file(unnamed / "lane.json", json{{"name", "linux-xdev"}, {"platform", "linux"}}.dump());
+    tk::write_file(unnamed / "cases.ndjson", json{{"program", "xdev"}, {"test", "Loopback.Case"},
+        {"status", "pass"}, {"ms", 7}}.dump() + "\n");
+    for (int again = 0; again != 2; ++again) {
+        const auto out = fixture.home.root() / std::format("unnamed-{}", again);
+        const auto rendered = fixture.run({"report", "--in", unnamed.string(), "--trend",
+            (failure / "trend.json").string(), "--write", out.string()});
+        EXPECT_EQ(rendered.exit_code, 0) << rendered.transcript();
+        EXPECT_EQ(json::parse(tk::read_file(out / "trend.json"))["observations"].size(), 3);
+        tk::write_file(unnamed / "cases.ndjson", json{{"program", "xdev"}, {"test", "Loopback.Case"},
+            {"status", "pass"}, {"ms", 9}}.dump() + "\n");
+    }
     tk::write_file(fixture.home.root() / "tests/unit/slow.cpp", "import std;");
     const auto inventory = fixture.discovery({json{{"member", "xdev"}, {"test", "unit/slow"},
         {"main", "tests/unit/slow.cpp"}, {"cases", json::array({test_case("Slow.Check")})}}});

mcpp.toml

@@ -41,7 +41,7 @@ members = [
 
 [package]
 name = "xlings"
-version = "2026.10.9.1"
+version = "2026.10.9.2"
 description = "Universal package management infrastructure tool with SubOS isolation"
 license = "Apache-2.0"
 repo = "https://github.com/openxlings/xlings"

src/core/config.cppm

@@ -11,7 +11,7 @@ import xlings.core.home;
 namespace xlings {
 
 export struct Info {
-    static constexpr std::string_view VERSION = "2026.10.9.1";
+    static constexpr std::string_view VERSION = "2026.10.9.2";
     static constexpr std::string_view REPO = "https://github.com/openxlings/xlings";
 };
 

src/core/xvm/materialize.cpp

@@ -395,13 +395,29 @@ std::expected<Prepared, std::string> preflight_materialization(
             if (!expanded) return std::unexpected(expanded.error());
         }
     }
+    // An asset a recipe declares that this payload does not have is not
+    // placed -- as before this materializer: recipes declare their assets
+    // across versions, and a version without one (gcc 15.1.0 ships no
+    // libasan.so) is not a broken install. What exists and cannot be read
+    // still refuses: that is not "absent".
+    for (auto it = operations.begin(); it != operations.end();) {
+        if (it->second.change.remove) { ++it; continue; }
+        std::error_code ec;
+        const auto status = fs::status(it->second.change.source, ec);
+        if (status.type() == fs::file_type::not_found
+            && (!ec || ec == std::errc::no_such_file_or_directory)) {
+            log::debug("[xvm] asset source missing, not placed: {}", it->second.change.source.string());
+            it = operations.erase(it);
+            continue;
+        }
+        if (ec) return std::unexpected(it->second.change.source.string() + ": asset source is unreadable: " + ec.message());
+        ++it;
+    }
     // A declared directory and another package's descendant must merge into
     // a real directory, never write through the existing payload link.
     for (auto& [destination, operation] : operations) {
         if (operation.change.remove) continue;
         std::error_code ec;
-        if (!fs::exists(operation.change.source, ec) || ec)
-            return std::unexpected(operation.change.source.string() + ": asset source is missing or unreadable");
         if (fs::is_directory(operation.change.source, ec)) {
             for (const auto& [child, nested] : operations)
                 if (!nested.change.remove && below_(destination, child)) operation.unwrap = true;

tests/unit/test_xvm_materialize.cpp

@@ -300,3 +300,27 @@ XTEST(XvmMaterialize, UseConflictDoesNotPublishMetadataOrDeleteUserHeaders, .are
     EXPECT_EQ(tk::read_file(scope / "usr/include/shared.h.xlings-new/sentinel"), "user staging");
     EXPECT_EQ(nlohmann::json::parse(tk::read_file(scope / ".xlings.json")), scopeConfig);
 }
+
+XTEST(XvmMaterialize, AnAssetThePayloadDoesNotShipIsNotPlacedAndDoesNotRefuseTheRest,
+      .area = "xvm", .covers = {"HOME-LAYER-RESOLVE"}) {
+    // gcc 15.1.0's recipe declares lib64/libasan.so, which that build does
+    // not ship. The 2026.10.9.1 materializer refused the whole update over it
+    // (fresh-install, gcc suite); an absent source is skipped, as it was
+    // before -- the others are placed.
+    auto home = tk::Home::isolated("asset-absent-source");
+    const auto scope = home.dir() / "subos/default";
+    const auto payload = home.dir() / "data/xpkgs/xim-x-gcc/15.1.0/lib64";
+    tk::write_file(payload / "libstdc++.so.6", "present");
+    const std::vector<m::AssetChange> changes{
+        {payload / "libstdc++.so.6", scope / "lib/libstdc++.so.6", false},
+        {payload / "libasan.so", scope / "lib/libasan.so", false},
+    };
+    auto prepared = m::preflight_materialization(changes, {}, scope);
+    ASSERT_TRUE(prepared) << prepared.error();
+    auto applied = prepared->execute();
+    ASSERT_TRUE(applied) << applied.error();
+    ASSERT_TRUE(applied->commit());
+    EXPECT_TRUE(fs::exists(scope / "lib/libstdc++.so.6"));
+    std::error_code ec;
+    EXPECT_FALSE(fs::exists(fs::symlink_status(scope / "lib/libasan.so", ec))) << "absent: not placed";
+}