huggingface/smolagents · warning · InterpreterError

This is not a correct function: {call.func}).

Error message

This is not a correct function: {call.func}).

What it means

evaluate_call only accepts callables reached via ast.Call, ast.Lambda, ast.Attribute, ast.Name, or ast.Subscript expressions; any other func node shape raises InterpreterError. It is a defensive structural check on the AST, not a runtime type error (the paren and period in the message are cosmetic).

Source

Thrown at src/smolagents/local_python_executor.py:833

            set_value(elem, value[i], state, static_tools, custom_tools, authorized_imports)
    elif isinstance(target, ast.Subscript):
        obj = evaluate_ast(target.value, state, static_tools, custom_tools, authorized_imports)
        key = evaluate_ast(target.slice, state, static_tools, custom_tools, authorized_imports)
        obj[key] = value
    elif isinstance(target, ast.Attribute):
        obj = evaluate_ast(target.value, state, static_tools, custom_tools, authorized_imports)
        setattr(obj, target.attr, value)


def evaluate_call(
    call: ast.Call,
    state: dict[str, Any],
    static_tools: dict[str, Callable],
    custom_tools: dict[str, Callable],
    authorized_imports: list[str],
) -> Any:
    if not isinstance(call.func, (ast.Call, ast.Lambda, ast.Attribute, ast.Name, ast.Subscript)):
        raise InterpreterError(f"This is not a correct function: {call.func}).")

    func, func_name = None, None

    if isinstance(call.func, ast.Call):
        func = evaluate_ast(call.func, state, static_tools, custom_tools, authorized_imports)
    elif isinstance(call.func, ast.Lambda):
        func = evaluate_ast(call.func, state, static_tools, custom_tools, authorized_imports)
    elif isinstance(call.func, ast.Attribute):
        obj = evaluate_ast(call.func.value, state, static_tools, custom_tools, authorized_imports)
        func_name = call.func.attr
        if not hasattr(obj, func_name):
            raise InterpreterError(f"Object {obj} has no attribute {func_name}")
        func = getattr(obj, func_name)
    elif isinstance(call.func, ast.Name):
        func_name = call.func.id
        if func_name in state:
            func = state[func_name]
        elif func_name in static_tools:

View on GitHub (pinned to 30bb116109)

Solutions

1. Ensure executed code uses standard call syntax (name, attribute, subscript, call or lambda as the callee)
2. If generating ASTs, keep call.func within the five supported node types
3. Execute source strings via evaluate_python/evaluate_script rather than custom ASTs

import ast
for node in ast.walk(ast.parse(code)):
    if isinstance(node, ast.Call) and not isinstance(node.func, (ast.Call, ast.Lambda, ast.Attribute, ast.Name, ast.Subscript)):
        raise ValueError('unsupported call target in AST')

from smolagents.local_python_executor import InterpreterError
try:
    evaluate_python(code)
except InterpreterError as e:
    if 'not a correct function' in str(e):
        raise SyntaxRestriction(str(e)) from e

When it happens

Trigger: Practically unreachable from normal Python source since the grammar only produces those node types for callees; fires only with hand-constructed/mutated ASTs (e.g. calling evaluate_ast directly with an exotic call.func node).

Common situations: Programmatic AST generation feeding the executor; AST transformers/optimizers that replace the callee with an unexpected node type.

Related errors

• Unary operation {expression.op.__class__.__name__} is not su
• Unsupported AnnAssign target in class body: {type(target).__
• AugAssign not supported for {type(target)} targets.
• Operation {type(expression.op).__name__} is not supported.
• Forbidden access to module: {result.__name__}

AI-assisted analysis of huggingface/smolagents@30bb116109 (2026-08-28). Data as JSON: /api/errors/23eba2897be24e20. Report an issue: GitHub.