NationalSecurityAgency/ghidra · error · RuntimeError

Invalid argument: {arg}

Error message

Invalid argument: {arg}

What it means

Thrown by the retain_values command handler in the drgn agent when the first element of key_list starts with '--' but is not one of the recognized flags (--elements, --attributes, --both). NOTE: the code has a latent inconsistency — it checks key_list[0] in the first and last branch but keys[0] in the middle two branches, suggesting keys and key_list may diverge in some code paths, potentially masking valid flags.

Source

Thrown at Ghidra/Debug/Debugger-agent-drgn/src/main/py/src/ghidradrgn/commands.py:839

    switch, then the switch is required. Only the first argument is taken as the
    switch. All others are taken as keys.
    """

    key_list = keys.split(" ")

    trace, tx = STATE.require_tx()
    kinds = 'elements'
    if key_list[0] == '--elements':
        kinds = 'elements'
        key_list = key_list[1:]
    elif keys[0] == '--attributes':
        kinds = 'attributes'
        key_list = key_list[1:]
    elif keys[0] == '--both':
        kinds = 'both'
        key_list = key_list[1:]
    elif key_list[0].startswith('--'):
        raise RuntimeError("Invalid argument: " + key_list[0])
    trace.proxy_object_path(path).retain_values(key_list, kinds=kinds)


def ghidra_trace_get_obj(path: str) -> None:
    """
    Get an object descriptor by its canonical path.

    This isn't the most informative, but it will at least confirm whether an
    object exists and provide its id.
    """

    trace = STATE.require_trace()
    object = trace.get_object(path)
    print("{}\t{}".format(object.id, object.path))


def ghidra_trace_get_values(pattern: str) -> None:
    """

View on GitHub (pinned to d5f144c24d)

Solutions

1. Use only recognized flags: --elements, --attributes, or --both.
2. Omit the flag entirely to default to 'elements'.
3. If the error persists with a correct flag, inspect the keys vs key_list variables in the source — there is a bug where --attributes and --both check keys[0] instead of key_list[0].

Example fix

// before
ghidra_trace_retain_values('Processes[]', '--all', 'key1', 'key2')
// after
ghidra_trace_retain_values('Processes[]', '--both', 'key1', 'key2')

VALID_FLAGS = {'--elements', '--attributes', '--both'}

def validate_retain_args(key_list):
    if key_list and key_list[0].startswith('--'):
        if key_list[0] not in VALID_FLAGS:
            raise ValueError(
                f"Unrecognized flag '{key_list[0]}'. Valid: {VALID_FLAGS}")
        return key_list[1:], key_list[0]
    return key_list, '--elements'

try:
    ghidra_trace_retain_values(path, *args)
except RuntimeError as e:
    if 'Invalid argument' in str(e):
        print(f"Use --elements, --attributes, or --both. Got: {e}")
    raise

When it happens

Trigger: Calling the retain_values command with an unrecognized flag like '--all', '--keys', or '--merge'. Also, if keys and key_list are different objects (due to the code bug), a valid '--attributes' or '--both' flag checked against keys[0] might fall through to the error branch if key_list[0] has already been modified.

Common situations: Misspelling a flag (e.g. '--atributes'); using a flag from a different version of the API; the keys/key_list variable inconsistency causing unexpected routing to the error branch.

Related errors

• port must be numeric
• address must be 'port' or 'host:port'
• Cannot convert '{}' to length
• {node} is not {err_msg}
• Address {address} is not in process {proc}

AI-assisted analysis of NationalSecurityAgency/ghidra@d5f144c24d (2026-08-14). Data as JSON: /api/errors/28807593c8d68a16. Report an issue: GitHub.