fix(cli): explain hardware GPU screenshot fallback (#5200)

packages/cli/src/ui/format.test.ts

@@ -64,16 +64,58 @@ describe("formatScreenshotFallbackHint", () => {
     platform: "linux" as const,
   };
 
-  it("explains the slow path only for linux + auto-probed software gpu + screenshot", () => {
+  it("explains Linux software screenshot capture after automatic GPU selection", () => {
     expect(formatScreenshotFallbackHint(slow)).toContain("BeginFrame did not run");
     expect(formatScreenshotFallbackHint({ ...slow, platform: "darwin" })).toBeUndefined();
-    expect(formatScreenshotFallbackHint({ ...slow, browserGpuMode: "hardware" })).toBeUndefined();
     expect(formatScreenshotFallbackHint({ ...slow, captureMode: "beginframe" })).toBeUndefined();
   });
 
+  it.each(["auto", "hardware"] as const)(
+    "explains hardware screenshot capture when GPU mode %s was requested",
+    (requestedGpuMode) => {
+      const hint = formatScreenshotFallbackHint({
+        ...slow,
+        browserGpuMode: "hardware",
+        requestedGpuMode,
+      });
+
+      expect(hint).toContain("BeginFrame did not run");
+      expect(hint).toContain("probe");
+      expect(hint).toContain("fewer --workers");
+      expect(hint).not.toContain("software GL");
+    },
+  );
+
+  it.each(["beginframe", "drawelement", "beginframe|screenshot", undefined])(
+    "does not claim BeginFrame was absent for capture mode %s",
+    (captureMode) => {
+      expect(
+        formatScreenshotFallbackHint({ ...slow, captureMode, browserGpuMode: "hardware" }),
+      ).toBeUndefined();
+    },
+  );
+
+  it.each(["darwin", "win32"] as const)("stays silent on %s", (platform) => {
+    expect(
+      formatScreenshotFallbackHint({ ...slow, platform, browserGpuMode: "hardware" }),
+    ).toBeUndefined();
+  });
+
   it("stays silent when software gpu was requested, as --docker and --no-browser-gpu do", () => {
     expect(formatScreenshotFallbackHint({ ...slow, requestedGpuMode: "software" })).toBeUndefined();
     expect(formatScreenshotFallbackHint({ ...slow, requestedGpuMode: undefined })).toBeUndefined();
+    expect(
+      formatScreenshotFallbackHint({
+        ...slow,
+        browserGpuMode: "hardware",
+        requestedGpuMode: "software",
+      }),
+    ).toBeUndefined();
+  });
+
+  it("stays silent when the observed GPU mode is unavailable", () => {
+    expect(formatScreenshotFallbackHint({ ...slow, browserGpuMode: undefined })).toBeUndefined();
+    expect(formatScreenshotFallbackHint({ ...slow, browserGpuMode: "unknown" })).toBeUndefined();
   });
 });
 

packages/cli/src/ui/format.ts

@@ -94,7 +94,7 @@ export function formatRenderPipelineDetail(input: {
 }
 
 /**
- * Why a Linux auto render stayed on screenshot after BeginFrame was requested.
+ * Why a Linux render stayed on screenshot after automatic or hardware GPU selection.
  * Silent when software was requested (--docker, --no-browser-gpu) or off Linux.
  */
 export function formatScreenshotFallbackHint(input: {
@@ -103,8 +103,21 @@ export function formatScreenshotFallbackHint(input: {
   requestedGpuMode?: BrowserGpuMode;
   platform: NodeJS.Platform;
 }): string | undefined {
-  if (input.platform !== "linux" || input.requestedGpuMode !== "auto") return undefined;
-  if (input.captureMode !== "screenshot" || input.browserGpuMode !== "software") return undefined;
+  if (
+    input.platform !== "linux" ||
+    (input.requestedGpuMode !== "auto" && input.requestedGpuMode !== "hardware")
+  ) {
+    return undefined;
+  }
+  if (input.captureMode !== "screenshot") return undefined;
+  if (input.browserGpuMode === "hardware") {
+    return (
+      "Screenshot capture (slower): BeginFrame did not run. Needs chrome-headless-shell and no " +
+      "--resolution upscale. A BeginFrame probe timeout can occur when browsers start together " +
+      "on one GPU; fewer --workers may help."
+    );
+  }
+  if (input.browserGpuMode !== "software" || input.requestedGpuMode !== "auto") return undefined;
   return (
     "Screenshot capture (slower): BeginFrame did not run. Needs chrome-headless-shell and no " +
     "--resolution upscale. Heavy compositions can stall on software GL."