compute: a sole-suspect failure explains sibling failures; cells bottom-align the expander

A failure that pins several unproven toolchains no longer blames all of
them when one of those versions is already the only suspect of another
failure on the same release: the 9.1.1 JDK 25 failures on SDK 36 pinned
build-tools 36.1.0, which had no success of its own and was reported as
failing.

Cells anchor the expander dots to the bottom edge, hide the secondary
label when the column is too narrow for it, and the grid's minimum width
grows so the label fits on most desktop viewports.

Author: rigor789

shared/compute.ts

@@ -201,31 +201,59 @@ export function verifiedPairs(
 
 /**
  * A failed build pins several toolchains at once and cannot say which one is
- * to blame, so a failure only implicates a toolchain version that no
- * successful build of the same release used.
+ * to blame. A failure therefore implicates only toolchain versions that no
+ * successful build of the same release used, and once one of its pinned
+ * versions is the sole suspect of another failure, that version explains the
+ * failure and the rest stay unjudged.
  */
 function verifiedFor(
 	packageName: string,
 	version: string,
 	verified: VerificationResult[],
 	outcome: ResultClass,
 ): VersionCompatibility["verified"] {
-	const forThisVersion = (pairs: ReturnType<typeof verifiedPairs>) =>
-		pairs.filter((pair) => pair.package === packageName && pair.version === version);
-	const successes = forThisVersion(verifiedPairs(verified, "success"));
-	const provenToWork = (pair: (typeof successes)[number]) =>
-		successes.some((ok) => ok.toolchain === pair.toolchain && sameLine(ok.toolchainVersion, pair.toolchainVersion));
+	const forThisVersion = (entries: VerificationResult[]) =>
+		entries.filter((entry) => entry.package === packageName && entry.version === version);
+	const successes = forThisVersion(verified).filter((entry) => classify(entry) === "success");
+	const provenToWork = (toolchain: ToolchainKey, toolchainVersion: string) =>
+		successes.some((ok) => {
+			const okVersion = ok.toolchains[toolchain as Exclude<ToolchainKey, "node">];
+			return okVersion !== undefined && sameLine(okVersion, toolchainVersion);
+		});
 
 	const result: VersionCompatibility["verified"] = {};
-	for (const pair of forThisVersion(verifiedPairs(verified, outcome))) {
-		if (outcome !== "success" && provenToWork(pair)) {
-			continue;
+	const add = (toolchain: ToolchainKey, toolchainVersion: string) => {
+		const list = (result[toolchain] ??= []);
+		if (!list.includes(toolchainVersion)) {
+			list.push(toolchainVersion);
+		}
+	};
+
+	if (outcome === "success") {
+		for (const pair of verifiedPairs(verified, "success")) {
+			if (pair.package === packageName && pair.version === version) {
+				add(pair.toolchain, pair.toolchainVersion);
+			}
 		}
-		const list = (result[pair.toolchain] ??= []);
-		if (!list.includes(pair.toolchainVersion)) {
-			list.push(pair.toolchainVersion);
+	} else {
+		const suspects = forThisVersion(verified)
+			.filter((entry) => classify(entry) === outcome)
+			.map((entry) =>
+				(Object.entries(entry.toolchains) as Array<[ToolchainKey, string]>).filter(
+					([toolchain, toolchainVersion]) => !provenToWork(toolchain, toolchainVersion),
+				),
+			);
+		const culprits = suspects.filter((pins) => pins.length === 1).map(([pin]) => pin);
+		for (const pins of suspects) {
+			const explained = culprits.find(([toolchain, toolchainVersion]) =>
+				pins.some(([key, value]) => key === toolchain && sameLine(value, toolchainVersion)),
+			);
+			for (const [toolchain, toolchainVersion] of explained ? [explained] : pins) {
+				add(toolchain, toolchainVersion);
+			}
 		}
 	}
+
 	for (const list of Object.values(result)) {
 		list.sort((a, b) => semver.rcompare(semver.coerce(a) ?? "0.0.0", semver.coerce(b) ?? "0.0.0"));
 	}

test/compute.test.ts

@@ -282,4 +282,28 @@ describe("failure attribution", () => {
 		expect(cellFor(doc, "@nativescript/android", "9.0.5", "buildTools", "37.0.0").state).toBe("unverified");
 		expect(cellFor(doc, "@nativescript/android", "9.0.5", "jdk", "25").state).toBe("unsupported");
 	});
+
+	it("does not blame an unproven toolchain when a sole suspect explains the failure", () => {
+		const doc = buildDocument({
+			generatedAt: "2026-09-09T00:00:00.000Z",
+			toolchains: { xcode: [], cocoapods: [], compileSdk: [{ version: "37" }, { version: "36" }], buildTools: [{ version: "37.0.0" }, { version: "36.1.0" }], jdk: [{ version: "25" }, { version: "21" }], node: [] },
+			packages: [
+				{
+					spec: { name: "@nativescript/android", toolchains: ["compileSdk", "buildTools", "jdk"], keep: 5 },
+					document: { distTags: {}, manifests: [{ version: "9.1.1", requirements: { jdk: ">=17" } }] },
+				},
+			],
+			overrides: { requirements: [], advisories: [] },
+			verified: [
+				{ package: "@nativescript/android", version: "9.1.1", toolchains: { compileSdk: "37", buildTools: "37.0.0", jdk: "21" }, with: { nativescript: "9.1.1", node: "24" }, recordedAt: "2026-09-09T00:00:00Z" },
+				{ package: "@nativescript/android", version: "9.1.1", toolchains: { compileSdk: "37", buildTools: "37.0.0", jdk: "25" }, with: { nativescript: "9.1.1", node: "24" }, outcome: "failure", attempts: 2, recordedAt: "2026-09-09T00:00:00Z" },
+				// build-tools 36.1.0 has no success of its own, but the failure is already explained by JDK 25.
+				{ package: "@nativescript/android", version: "9.1.1", toolchains: { compileSdk: "36", buildTools: "36.1.0", jdk: "25" }, with: { nativescript: "9.1.1", node: "24" }, outcome: "failure", attempts: 2, recordedAt: "2026-09-09T00:00:00Z" },
+			],
+		});
+		const v911 = doc.packages["@nativescript/android"].versions["9.1.1"];
+		expect(v911.failed).toEqual({ jdk: ["25"] });
+		expect(cellFor(doc, "@nativescript/android", "9.1.1", "buildTools", "36.1.0").state).toBe("unverified");
+		expect(cellFor(doc, "@nativescript/android", "9.1.1", "compileSdk", "36").state).toBe("unverified");
+	});
 });

web/src/components/CompatCell.vue

@@ -50,34 +50,37 @@ const background = computed(() => {
 
 <template>
 	<td
-		class="relative cursor-pointer px-3 pt-3.5 pb-2.5 text-center align-top transition-colors outline-none focus-visible:ring-2 focus-visible:ring-declared/50 focus-visible:ring-inset"
+		class="relative cursor-pointer px-3 pt-3.5 pb-6 text-center align-top transition-colors outline-none focus-visible:ring-2 focus-visible:ring-declared/50 focus-visible:ring-inset"
 		:class="background"
 		tabindex="0"
 		:title="`${STATE_HELP[state]} ${open ? 'Click to collapse.' : 'Click for details.'}`"
 		@click="emit('toggle')"
 		@keydown.enter.prevent="emit('toggle')"
 		@keydown.space.prevent="emit('toggle')"
 	>
-		<StateIcon :state="state" :size="22" class="mx-auto" />
-		<span class="mt-1 block tabular-nums" :class="TEXT[state]">{{ primary?.version ?? "No data" }}</span>
-		<span
-			v-if="secondary"
-			class="mt-0.5 flex items-center justify-center gap-1 text-[11px] tabular-nums"
-			:title="`${secondary.version}: ${secondary.cell.reason}`"
-		>
-			<StateIcon :state="secondary.cell.state" :size="12" />
-			<span class="font-medium" :class="TEXT[secondary.cell.state]">{{ secondary.version }}</span>
-			<span class="text-neutral-500 dark:text-neutral-400">{{ SECONDARY_LABEL[secondary.cell.state] }}</span>
-		</span>
-		<span
-			v-if="summary.prerelease"
-			class="mt-0.5 flex items-center justify-center gap-1 text-[11px] tabular-nums text-neutral-500 dark:text-neutral-400"
-			:title="`${summary.prerelease.version} beta: ${summary.prerelease.cell.reason}`"
-		>
-			<StateIcon :state="summary.prerelease.cell.state" :size="12" />
-			{{ summary.prerelease.version }}
-			<BetaChip />
-		</span>
+		<!-- The label hides when the column is narrower than the line. -->
+		<div class="@container">
+			<StateIcon :state="state" :size="22" class="mx-auto" />
+			<span class="mt-1 block tabular-nums" :class="TEXT[state]">{{ primary?.version ?? "No data" }}</span>
+			<span
+				v-if="secondary"
+				class="mt-0.5 flex items-center justify-center gap-1 text-[11px] tabular-nums"
+				:title="`${secondary.version}: ${secondary.cell.reason}`"
+			>
+				<StateIcon :state="secondary.cell.state" :size="12" />
+				<span class="font-medium" :class="TEXT[secondary.cell.state]">{{ secondary.version }}</span>
+				<span class="text-neutral-500 @max-[7rem]:hidden dark:text-neutral-400">{{ SECONDARY_LABEL[secondary.cell.state] }}</span>
+			</span>
+			<span
+				v-if="summary.prerelease"
+				class="mt-0.5 flex items-center justify-center gap-1 text-[11px] tabular-nums text-neutral-500 dark:text-neutral-400"
+				:title="`${summary.prerelease.version} beta: ${summary.prerelease.cell.reason}`"
+			>
+				<StateIcon :state="summary.prerelease.cell.state" :size="12" />
+				{{ summary.prerelease.version }}
+				<BetaChip />
+			</span>
+		</div>
 		<span
 			v-if="flagged"
 			class="absolute top-1.5 right-2 flex items-center gap-0.5 text-xs font-bold text-advisory"
@@ -86,6 +89,6 @@ const background = computed(() => {
 			<StateIcon state="advisory" :size="16" />
 			<span v-if="summary.advisories.length > 1">{{ summary.advisories.length }}</span>
 		</span>
-		<span class="mt-0.5 block text-xs leading-none tracking-widest text-neutral-400" aria-hidden="true">···</span>
+		<span class="absolute inset-x-0 bottom-2 block text-xs leading-none tracking-widest text-neutral-400" aria-hidden="true">···</span>
 	</td>
 </template>

web/src/components/CompatGrid.vue

@@ -86,7 +86,7 @@ const headCell = `sticky z-10 bg-neutral-50 text-center font-semibold dark:bg-ne
 	<!-- Below the desktop breakpoint the grid scrolls sideways inside this wrapper; above it, the
 	     table fits the page, the wrapper does not clip, and the header can stay pinned. -->
 	<div class="overflow-x-auto border-y border-neutral-200 lg:overflow-visible dark:border-neutral-700/80">
-		<table class="w-full min-w-[60rem] table-fixed border-separate border-spacing-0 text-sm">
+		<table class="w-full min-w-[66rem] table-fixed border-separate border-spacing-0 text-sm">
 			<colgroup>
 				<col class="w-88" />
 				<col v-for="key in ALL_KEYS" :key="key" />