ruvnet/ruflo · error · Error

KV cache file missing SHA256 footer

Error message

KV cache file missing SHA256 footer

What it means

Thrown by loadKvCache after the entry loop when offset + 32 > data.length — the file has no room for the mandatory 32-byte SHA-256 footer. The footer is the integrity check for all entry data, so its absence means the file is incomplete or was not produced by a conformant writer.

Source

Thrown at v3/@claude-flow/cli/src/appliance/gguf-engine.ts:412

    if (version !== RVKV_VERSION) throw new Error(`Unsupported KV cache version: ${version}`);

    const entryCount = data.readUInt32LE(40);
    let offset = 44;
    const entries = new Map<string, Buffer>();

    for (let i = 0; i < entryCount; i++) {
      if (offset + 8 > data.length) throw new Error('KV cache file truncated');
      const keyLen = data.readUInt32LE(offset);
      const valLen = data.readUInt32LE(offset + 4);
      offset += 8;
      if (offset + keyLen + valLen > data.length) throw new Error('KV cache file truncated');
      entries.set(data.toString('utf-8', offset, offset + keyLen), Buffer.from(data.subarray(offset + keyLen, offset + keyLen + valLen)));
      offset += keyLen + valLen;
    }

    // Verify footer hash (mandatory)
    if (offset + 32 > data.length) {
      throw new Error('KV cache file missing SHA256 footer');
    }
    const stored = data.subarray(offset, offset + 32);
    const computed = createHash('sha256').update(data.subarray(44, offset)).digest();
    if (!stored.equals(computed)) throw new Error('KV cache integrity check failed: hash mismatch');

    this.kvCache = entries;
    if (this.config.verbose) console.log(`[gguf-engine] KV cache loaded: ${entries.size} entries`);
  }

  /** Return metadata for all loaded models. */
  getLoadedModels(): GgufMetadata[] { return Array.from(this.loadedModels.values()); }

  /** Store a key-value pair in the in-memory KV cache. */
  setKvEntry(key: string, value: Buffer): void { this.kvCache.set(key, value); }

  /** Retrieve a key-value pair from the in-memory KV cache. */
  getKvEntry(key: string): Buffer | undefined { return this.kvCache.get(key); }

View on GitHub (pinned to 6b01dc5a68)

Solutions

1. Regenerate the cache with persistKvCache and confirm it completes (atomic write-then-rename prevents half-footers).
2. Delete the footerless file and cold-start.
3. Treat missing-footer as recoverable in loadKvCache's caller (catch and continue without cache).
4. Verify no external process (backup/cleanup agent) is truncating cache files.

Example fix

// before
await engine.loadKvCache(path);

// after
try {
  await engine.loadKvCache(path);
} catch (e) {
  if (e instanceof Error && /missing SHA256 footer/.test(e.message)) {
    logger.warn({ path }, 'KV cache missing footer; regenerating');
    await fsUnlink(path).catch(() => {});
  } else throw e;
}

// Ensure the file has room for the 32-byte footer:
const data = await readFile(path);
if (data.length < 44 + 32) {
  await fsUnlink(path).catch(() => {});
  return; // cannot contain header + footer
}
await engine.loadKvCache(path);

function hasRoomForFooter(size: number): boolean {
  return size >= 44 + 32;
}

try {
  await engine.loadKvCache(path);
} catch (e) {
  if (e instanceof Error && /missing SHA256 footer/.test(e.message)) {
    await fsUnlink(path).catch(() => {});
    return;
  }
  throw e;
}

When it happens

Trigger: All declared entries were consumed but the file ends without the trailing 32-byte SHA-256 digest — e.g. persistKvCache was interrupted after writing entries but before (or during) the footer, or the file was trimmed by an external process.

Common situations: Crash during the final Buffer.concat/write of persistKvCache (footer is the last component); a tool that stripped trailing bytes; a cache written by an older writer that did not emit a footer (in which case version mismatch would normally fire first).

Related errors

• KV cache integrity check failed: hash mismatch
• KV cache file too small
• Invalid KV cache magic: 0x${magic.toString(16)}
• KV cache file truncated
• No KV cache output path specified

AI-assisted analysis of ruvnet/ruflo@6b01dc5a68 (2026-08-12). Data as JSON: /api/errors/da8f9952fcd8ce70. Report an issue: GitHub.