JuliusBrussee/caveman · error · Error

${markerPath} is not a valid Caveman ownership journal; refu

Error message

${markerPath} is not a valid Caveman ownership journal; refusing overwrite

What it means

Validation of the pre-existing ownership journal (marker file) under cavemanHome()/mcp before an MCP transaction writes it: the file exists but does not parse as a Caveman ownership journal. Overwriting it would destroy an unknown owner record, so the transaction refuses to proceed.

Source

Thrown at packages/cli/src/index.ts:12515

function transactOwnedMcpConfig(
  agent: "kilo" | "qwen",
  serverName: string,
  action: "install" | "uninstall",
  mcp?: { command: string; args: string[] },
  lockedConfigPath?: string,
): boolean {
  const plan = action === "install"
    ? agent === "kilo" ? planMcpKiloJson(mcp!, serverName) : planMcpQwenJson(mcp!, serverName)
    : agent === "kilo" ? planRemoveMcpKiloJson(serverName) : planRemoveMcpQwenJson(serverName);
  if (!plan) return false;
  if (lockedConfigPath && plan.path !== canonicalMcpConfigPath(lockedConfigPath)) {
    throw new Error(`${agent} ${serverName} MCP config target changed while acquiring lock; refusing mutation`);
  }

  const markerPath = canonicalOwnedMcpMarkerPath(agent, serverName);
  const markerBefore = fileBytes(markerPath);
  if (markerBefore !== null && !validMcpMarkerBytes(markerBefore, agent, serverName)) {
    throw new Error(`${markerPath} is not a valid Caveman ownership journal; refusing overwrite`);
  }
  const markerBeforeMode = markerBefore === null ? 0o600 : statSync(markerPath).mode & 0o777;
  if (!optionalBytesEqual(fileBytes(markerPath), markerBefore)) {
    throw new Error(`${markerPath} changed while planning MCP update; refusing overwrite`);
  }
  const markerAfter = action === "install" ? mcpMarkerBytes(mcp!, mcpServerToolName(serverName)!, plan.path) : null;
  if (!plan.changed && optionalBytesEqual(markerBefore, markerAfter)) return true;

  const journal: OwnedMcpPendingJournal = {
    schema_version: 1,
    transaction_id: randomUUID(),
    agent,
    server_name: serverName,
    action,
    config_path: plan.path,
    marker_path: markerPath,
    config_before_base64: plan.before?.toString("base64") ?? null,
    config_before_mode: plan.beforeMode,

View on GitHub (pinned to 5184b3d11a)

Solutions

1. Inspect the marker file named in the message; if it is stale or hand-edited, back it up and remove it, then re-run the install
2. If another tool created the file, reconcile ownership manually before using Caveman-managed MCP
3. Ensure the Caveman version writing journals matches the one reading them (no cross-version format drift)

When it happens

Trigger: Thrown at packages/cli/src/index.ts:12515 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of JuliusBrussee/caveman@5184b3d11a (2026-09-06). Data as JSON: /api/errors/29cc3dfd03c226dc. Report an issue: GitHub.