Parameter pack type cannot be Sendable?

[mattmassicotte]

Description

Having a hard time figuring out how to make parameter pack types Sendable.

error: capture of 'parameters' with non-sendable type 'repeat each ParameterType' in a `@Sendable` closure
 5 | ) -> @Sendable () async -> Void where repeat each ParameterType: Sendable {
 6 |     {
 7 |         await effect(repeat each parameters)
   |                                  `- error: capture of 'parameters' with non-sendable type 'repeat each ParameterType' in a `@Sendable` closure
 8 |     }
 9 | }

Reproduction

func doThing<each ParameterType: Sendable>(
    _ effect: @Sendable @escaping (repeat each ParameterType) async -> Void,
    with parameters: repeat each ParameterType
) -> @Sendable () async -> Void {
    {
        await effect(repeat each parameters)
    }
}

Expected behavior

This should compile without error.

Environment

Apple Swift version 6.0-dev (LLVM bf8bbb910874156, Swift a0bb875)
Target: arm64-apple-macosx14.0

Additional information

No response