JuliusBrussee/caveman · error · Error

caveman build: agent definition contains an unsupported valu

Error message

caveman build: agent definition contains an unsupported value

What it means

Error "caveman build: agent definition contains an unsupported value" thrown in JuliusBrussee/caveman.

Source

Thrown at packages/agent/src/build.ts:582

export function toolDefinitionSHA256(tool: ToolDefinition): string {
  return sha256(stableStringify(lockableValue(tool, new WeakSet<object>())));
}

export function contextIRSHA256(contextIR: ContextIR): string {
  return sha256(stableStringify(contextIRToWire(contextIR)));
}

function lockableValue(value: unknown, seen: WeakSet<object>): unknown {
  if (value === null || typeof value === "string" || typeof value === "boolean" ||
      typeof value === "number") {
    return value;
  }
  if (typeof value === "bigint") return { cave_bigint: value.toString() };
  if (typeof value === "function" || typeof value === "undefined" || typeof value === "symbol") {
    return undefined;
  }
  if (typeof value !== "object") {
    throw new Error("caveman build: agent definition contains an unsupported value");
  }
  if (seen.has(value)) throw new Error("caveman build: cyclic agent definition is not lockable");
  seen.add(value);
  try {
    if (Array.isArray(value)) {
      return value.map((item) => lockableValue(item, seen) ?? null);
    }
    const projected: Record<string, unknown> = {};
    for (const [key, item] of Object.entries(value)) {
      const locked = lockableValue(item, seen);
      if (locked !== undefined) projected[key] = locked;
    }
    const implementationSource = Reflect.get(
      value,
      Symbol.for("@caveman-ai/agent:tool-implementation-source"),
    );
    if (typeof implementationSource === "string") {
      projected.cave_tool_implementation_sha256 = sha256(implementationSource);

View on GitHub (pinned to 27d5a3981a)

Solutions

1. Remove the unsupported value from the agent definition; only canonically serializable values are lockable.

When it happens

Trigger: Thrown at packages/agent/src/build.ts:582 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of JuliusBrussee/caveman@27d5a3981a (2026-08-15). Data as JSON: /api/errors/d6272fa2e2584c68. Report an issue: GitHub.