Mixin template parameter overloading bug?

[monkyyy]

On Saturday, 14 June 2025 at 23:49:19 UTC, Steven Schveighoffer 
wrote:
>
> If I had to guess, I think the compiler is not able to exactly 
> deduce what form your lambda should be instantiated with. I 
> think it's picking the first form it sees.
>
> I think if anything, the error message is really weird. I'd 
> expect possibly an ambiguity error. But I'm not sure the 
> language is supposed to handle your case.
>
> -Steve

theres correct ambiguity errors when the return types are well 
typed; the code was wierd but I confirm theres a bug in here