NationalSecurityAgency/ghidra · error · TypeError

Method requires trace binding

Error message

Method requires trace binding

What it means

Raised as TypeError by Client._read_argument() when an incoming method argument has schema OBJECT but there is no Trace bound to the invocation (trace is None). An OBJECT argument must be materialized as a TraceObject belonging to a specific Trace; with no trace binding there is nowhere to anchor the object, so the deserialization cannot proceed.

Source

Thrown at Ghidra/Debug/Debugger-rmi-trace/src/main/py/src/ghidratrace/client.py:1274

        return self._batch_or_now(root, 'reply_get_object', _handle)

    @staticmethod
    def _read_values(reply: bufs.ReplyGetValues) -> List[Tuple[
            DetachedObject, Lifespan, str, Tuple[Any, sch.Schema]]]:
        return [
            (Client._read_obj_desc(v.parent), Client._read_span(v.span),
             v.key, Client._read_value(v.value))
            for v in reply.values
        ]

    @staticmethod
    def _read_argument(arg: bufs.MethodArgument,
                       trace: Optional[Trace]) -> Tuple[str, Any]:
        name = arg.name
        value, schema = Client._read_value(arg.value)
        if schema is sch.OBJECT:
            if trace is None:
                raise TypeError("Method requires trace binding")
            if not isinstance(value, DetachedObject):
                raise TypeError(
                    "Internal: sch.OBJECT expects DetachedObject in args")
            id, path = value.id, value.path
            return name, trace.proxy_object(id=id, path=path)
        return name, value

    @staticmethod
    def _read_arguments(arguments: Iterable[bufs.MethodArgument],
                        trace: Optional[Trace]) -> Dict[str, Any]:
        kwargs = {}
        for arg in arguments:
            name, value = Client._read_argument(arg, trace)
            kwargs[name] = value
        return kwargs

    def _get_values(self, id: int, span: Lifespan, pattern: str) -> Union[
        List[Tuple[DetachedObject, Lifespan, str, Tuple[Any, sch.Schema]]],

View on GitHub (pinned to d5f144c24d)

Solutions

1. Ensure methods that declare OBJECT arguments are bound to a trace (include an oid in the invocation).
2. Re-check the method's registration metadata so the trace-required flag matches its argument schema.
3. If the method is genuinely trace-less, do not declare object-typed arguments.

Example fix

// before: method registered as trace-less but takes an object arg
// after: bind the invocation to a trace / mark the method as trace-required

if arg_schema == sch.OBJECT and trace is None:
    raise TypeError('Cannot bind object arg without a trace')

When it happens

Trigger: The server invokes a registered method whose argument list includes an OBJECT-typed parameter, but the request carried no oid (no trace was bound). This happens when a method is registered as not requiring a trace yet declares an object argument, or when a client invokes a method without an oid but passes an object.

Common situations: Registering a method with @method decorators where the trace binding flag disagrees with the presence of object arguments; client/server method-schema disagreement.

Related errors

• Object/proxy has neither id nor path!: {}
• Must have id or path
• Cannot convert: {value:r}
• Cannot write Value: {schema}, {value}, {type(value)}
• Could not read value: {}

AI-assisted analysis of NationalSecurityAgency/ghidra@d5f144c24d (2026-08-14). Data as JSON: /api/errors/b83a2936f7856611. Report an issue: GitHub.