pbakaus/impeccable · warning

[impeccable] Could not read source to check the variant wrap

Error message

[impeccable] Could not read source to check the variant wrapper; keeping the session: 

What it means

During the orphan probe, the script fetches the session's source file via the local /source endpoint to check whether the variant wrapper still exists. When the read itself fails for a non-conclusive reason — the server briefly unavailable, a transient fetch error, or a non-404 HTTP error — after exhausting the 3-retry budget it logs this warning but deliberately KEEPS the session, because an unreadable file says nothing about whether the wrapper is gone. A toast tells the user the check will re-run on the next event.

Source

Thrown at skill/scripts/live-browser.js:6265

        injectVariantsFromSource(filePath, sessionId, { ...opts, _orphanAttempt: attempt + 1 });
      }, COMPLETED_SOURCE_FALLBACK_RETRY_MS);
    };
    // Discarding is durable (the session moves to the discarded phase and the
    // picker replaces it), so it needs evidence that the wrapper is gone: a
    // read that answers without the marker, or a 404 (the file itself was
    // renamed or deleted). Either kind retries on the shared budget first.
    // A read that fails for any other reason (the server briefly away, a
    // transient fetch error) says nothing about the wrapper; after the budget
    // the session is kept, the user told, and the next event retries.
    const onNoWrapper = (reason) => {
      if (!stillActive()) return;
      if (attempt < COMPLETED_SOURCE_FALLBACK_RETRIES) { retryLater(); return; }
      discardOrphanedSession(reason);
    };
    const onUnreadable = (detail) => {
      if (!stillActive()) return;
      if (attempt < COMPLETED_SOURCE_FALLBACK_RETRIES) { retryLater(); return; }
      console.warn('[impeccable] Could not read source to check the variant wrapper; keeping the session: ' + detail);
      showToast('Could not read the source file to check this session; it stays open and is checked again on the next event.', 5500);
    };
    fetch(url)
      .then(r => { if (!r.ok) throw new Error('source read failed: ' + r.status); return r.text(); })
      .then(text => {
        if (!stillActive()) return;
        if (sourceHasSessionWrapper(text, sessionId)) return;
        onNoWrapper('variant wrapper missing from source');
      })
      .catch(err => {
        const detail = err && err.message ? err.message : 'fetch failed';
        if (/source read failed: 404$/.test(detail)) {
          onNoWrapper('source file missing (404) while checking for the variant wrapper');
          return;
        }
        onUnreadable(detail);
      });
  }

View on GitHub (pinned to 2bc2879276)

Solutions

1. Do nothing destructive — the session is intentionally kept and rechecked on the next event.
2. Verify the live server is running on the expected port (restart the live server if it was mid-restart).
3. Check the /source endpoint URL, token, and file path by fetching it manually from the page context.
4. Disable interfering service workers or proxies on localhost during live mode.

const url = 'http://localhost:' + PORT + '/source?token=' + TOKEN + '&path=' + encodeURIComponent(filePath);
// pre-check reachability before trusting a read failure as conclusive
const reachable = await fetch(url, { method: 'HEAD' }).then(r => r.ok).catch(() => false);

fetch(url)
  .then(r => { if (!r.ok) throw new Error('source read failed: ' + r.status); return r.text(); })
  .catch(err => {
    // non-conclusive: keep the session, recheck on the next event
    console.warn('could not read source; keeping session:', err.message);
  });

When it happens

Trigger: fetch of http://localhost:PORT/source?token=...&path=... fails (network/TypeError) or returns a non-OK status other than a conclusive 404, on every retry attempt (attempt >= COMPLETED_SOURCE_FALLBACK_RETRIES === 3) while the session is active.

Common situations: The live server was restarting mid-check; the dev machine slept or the port changed; a proxy or service worker intercepted the fetch; token/appRoot mismatch causing repeated auth-style failures rather than 404.

Understand the failure class

Background: 'Something went wrong' / 'Request failed (500)' / 'HTTP error! status: 404' — what failed HTTP requests actually mean and how to find the real cause — this error's family across 28 libraries.

Related errors

• ${String(res.status)}
• source read failed: ${r.status}
• TypeError: fetch failed: {}
• [impeccable] failed to fetch pending count:
• [impeccable] Discarding orphaned session

AI-assisted analysis of pbakaus/impeccable@2bc2879276 (2026-09-08). Data as JSON: /api/errors/eaba3f58437cdc63. Report an issue: GitHub.