Defining System.Void in compilation suppresses error about usage of System.Void

[RikkiGibson]

Version Used: e6b5dd8

Steps to Reproduce:

SharpLab

using System;

namespace System
{
    public class Void { } // comment out to get an error instead of a warning
}

public class C {
    public void M(Void v) {  // warning CS0436: The type 'Void' in '_' conflicts with the imported type 'void'
    }
}

Expected Behavior: An error is reported regardless of whether Void is defined in source.

Actual Behavior: An error is only reported when Void is not defined in source.

[jcouv]

Good find.
However, this is likely an old issue and seems niche. Moving to backlog. Feel free to raise priority if appropriate.

[gafter]

I suspect this is not a bug. Defining your own System.Void doesn't define the one that void refers to - that type is always the System.Void that comes from the "core library". (Your assembly isn't the core library)