The following code compiles and runs, but shouldn't: ```fsharp type DU = Case of int let f du = match du with | Case -> printfn "hello!" [<EntryPoint>] let main argv = f (Case 1) 0 // return an integer exit code ``` `Case ->` should be a compile error, resolvable by `Case _ ->` or `Case x ->`. This is with latest .NET SDK 3.1.300, and was not the case with 3.1.200.