Mixin template parameter overloading bug?

[Andrey Zherikov]

On Saturday, 14 June 2025 at 00:02:32 UTC, Andrey Zherikov wrote:
Simplified test case a bit more.
This works:
```d
template f(void function(int) F) {}
template f(int function(int) F) {}

mixin f!((int _) {});
mixin f!((int _) => 0);

mixin f!((int) {});
mixin f!((int) => 0);

mixin f!((_) {});
mixin f!((_) => 0);  // Error: cannot return non-void from `void` 
function
```

Can anyone explain why adding type of the parameter in lambda 
(`int`) makes this working?