generics_typevartuple_basic_2 error

TypeVarTuple must be unpacked with * operator

When a TypeVarTuple is used in a generic class base list or as a direct type annotation, it must be unpacked using the * operator. Using a TypeVarTuple without unpacking is invalid per PEP 646.

from typing import Generic, TypeVarTuple

Ts = TypeVarTuple("Ts")

# BAD
class Cls(Generic[Ts]):  # E: TypeVarTuple must be unpacked with *
    ...

def f(*args: Ts) -> None:  # E: TypeVarTuple must be unpacked with *
    ...

# GOOD
class Cls2(Generic[*Ts]):  # OK
    ...

def f2(*args: *Ts) -> None:  # OK
    ...

How to handle it

Every rule is on by default — strict is the default, not a cage. You can dial generics_typevartuple_basic_2 down per-file or per-path from your editor or pyproject.toml, or fix the code so it type-checks. See the Type System rules and the complete diagnostic reference.

Canonical URL: https://www.basilisk-python.dev/errors/generics_typevartuple_basic_2