{"record":{"id":"c1380f587c3db74d","repo":"pbakaus/impeccable","slug":"impeccable-capture-failed-proceeding-without-sc","errorCode":null,"errorMessage":"[impeccable] capture failed, proceeding without screenshot:","messagePattern":"\\[impeccable\\] capture failed, proceeding without screenshot:","errorType":"console","errorClass":null,"httpStatus":null,"severity":"warning","filePath":"skill/scripts/live-browser.js","lineNumber":8039,"sourceCode":"  async function captureAndEmit(el, basePayload, snapshot, rect) {\n    const hasAnnotations = snapshot && (snapshot.comments.length > 0 || snapshot.strokes.length > 0);\n\n    // Plain requests do not send a screenshot to the agent, so capture is\n    // presentation-only. Wait only for the helper to accept the event before\n    // starting CPU-heavy capture; this yields the browser task and prevents\n    // rasterization from delaying the fetch itself.\n    if (!hasAnnotations) {\n      basePayload.clientSentAt = Date.now();\n      await sendEvent(basePayload);\n    }\n\n    let screenshotPath;\n    let blob;\n    let paper;\n    try {\n      ({ blob, paper } = await captureElementToBlob(el, snapshot, rect));\n    } catch (err) {\n      console.warn('[impeccable] capture failed, proceeding without screenshot:', err);\n    }\n    // Light up the shader overlay the moment capture is ready - no reason to\n    // wait for the upload to complete before the user sees something alive.\n    if (blob && state === 'GENERATING') {\n      showShaderOverlay(el, blob, rect, paper);\n    }\n    // Only upload + forward the screenshot when annotations (comments/strokes)\n    // are present. Without annotations the image is pure visual anchoring -\n    // it biases the model toward the current rendering and works against the\n    // three-distinct-directions brief.\n    if (blob && hasAnnotations) {\n      try {\n        const uploadRes = await fetch(\n          'http://localhost:' + PORT + '/annotation?token=' + encodeURIComponent(TOKEN) +\n          '&eventId=' + encodeURIComponent(basePayload.id),\n          { method: 'POST', headers: { 'Content-Type': 'image/png' }, body: blob },\n        );\n        if (uploadRes.ok) {","sourceCodeStart":8021,"sourceCodeEnd":8057,"githubUrl":"https://github.com/pbakaus/impeccable/blob/f88b2837a7d7c3182e46307bbbb091a1ed547571/skill/scripts/live-browser.js#L8021-L8057","documentation":"Before dispatching a generate/steer event, the client captures the target element to a PNG blob via captureElementToBlob. If that capture throws (modern-screenshot failure, tainted canvas, layout mid-transition), the error is logged as 'capture failed, proceeding without screenshot:' and the flow continues without the image: non-annotated events were already sent before capture, annotated ones are sent afterwards minus the screenshotPath.","triggerScenarios":"modern-screenshot throws on the element (foreignObject-hostile content, cross-origin images without CORS, fonts still loading); capture racing a hot-reload remount of the target; capturing during page teardown.","commonSituations":"Dev-server hot reload swaps the element mid-capture; target contains cross-origin <img> without CORS headers; heavy pages where the rasterizer times out or OOMs.","solutions":["Check the request still succeeded — the event goes through without the screenshot","Retrigger the generate to get a screenshot-backed run if visual anchoring mattered","Serve images/fonts with permissive CORS so the canvas is not tainted"],"exampleFix":null,"handlingStrategy":"fallback","validationCode":"if (!el.isConnected) { sendWithoutScreenshot(); return; } // capture is pointless on detached elements","typeGuard":null,"tryCatchPattern":"try { ({ blob, paper } = await captureElementToBlob(el, snapshot, rect)); } catch (err) { console.warn('capture failed', err); } // event still dispatched without screenshotPath","preventionTips":["Do not trigger generate during hot-reload churn — wait for the DOM to settle","Fix cross-origin asset CORS so canvas capture is reliable","Design consumers to treat the screenshot as optional anchoring, never required input"],"tags":["screenshot","capture","generate-flow","fallback"],"backgroundTag":"screenshot-capture-failed","analyzedSha":"f88b2837a7d7c3182e46307bbbb091a1ed547571","analyzedAt":"2026-08-18T04:58:36.608Z","schemaVersion":2},"datasetVersion":"2026-08-30T08:17:16.595Z"}