earendil-works/pi · error · SessionHeaderScanLimitError

Session header exceeds ${MAX_SESSION_HEADER_SCAN_BYTES}-byte

Error message

Session header exceeds ${MAX_SESSION_HEADER_SCAN_BYTES}-byte scan limit: ${filePath}

What it means

Error "Session header exceeds ${MAX_SESSION_HEADER_SCAN_BYTES}-byte scan limit: ${filePath}" thrown in earendil-works/pi.

Source

Thrown at packages/coding-agent/src/core/session-manager.ts:609

			while (newlineIndex !== -1) {
				lineChunks.push(chunk.slice(lineStart, newlineIndex));
				const header = parseSessionHeaderCandidate(lineChunks.join(""));
				if (header !== undefined) return header;
				lineChunks.length = 0;
				lineStart = newlineIndex + 1;
				newlineIndex = chunk.indexOf("\n", lineStart);
			}
			lineChunks.push(chunk.slice(lineStart));
		}

		// Probe for EOF so a final header without a newline is allowed when it ends
		// exactly at the scan limit. Any additional byte exceeds the bounded scan.
		const probe = Buffer.allocUnsafe(1);
		if (readSync(fd, probe, 0, probe.length, null) === 0) {
			lineChunks.push(decoder.end());
			return parseSessionHeaderCandidate(lineChunks.join("")) ?? null;
		}
		throw new SessionHeaderScanLimitError(filePath);
	} finally {
		closeSync(fd);
	}
}

function readSessionHeaderForDiscovery(filePath: string): SessionHeader | null {
	try {
		return readSessionHeader(filePath);
	} catch {
		// Discovery is best-effort: unreadable or oversized files are not sessions,
		// and one corrupt file must not prevent other sessions from being found.
		return null;
	}
}

function getSessionHeaderCwd(header: SessionHeader): string | undefined {
	const cwd = (header as { cwd?: unknown }).cwd;
	return typeof cwd === "string" ? cwd : undefined;

View on GitHub (pinned to 4af9d21d3b)

When it happens

Trigger: Thrown at packages/coding-agent/src/core/session-manager.ts:609 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of earendil-works/pi@4af9d21d3b (2026-08-24). Data as JSON: /api/errors/8a0949a173b1a8f5. Report an issue: GitHub.