`Delegate.Method` doesn't work with open instance delegates over methods on a generic type in CoreCLR

[SingleAccretion]

Reproduction: godbolt.

Expected behavior: things work.
Actual behavior:

Unhandled exception. System.ArgumentException: Type handle 'Program+OpenInstanceDelStruct`1[System.Int32]&' and method handle with declaring type 'Program+OpenInstanceDelStruct`1[System.Int32]' are incompatible. Get RuntimeMethodHandle and declaring RuntimeTypeHandle off the same MethodBase.
   at System.RuntimeType.GetMethodBase(RuntimeType reflectedType, RuntimeMethodHandleInternal methodHandle)
   at System.Delegate.GetMethodImpl()
   at System.Diagnostics.DiagnosticMethodInfo.Create(Delegate delegate)
   at Program.Main() in /app/example.cs:line 11

[tommcdon]

@MichalStrehovsky would you mind take a look?

[MichalStrehovsky]

This API doesn't do anything but call Delegate.Method property on CoreCLR. If it's throwing, it would be a reflection bug.

[steveharter]

Here's a minimal repro:

...
        MethodInfo delMethod = typeof(OpenInstanceDelStruct<int>).GetMethod("InstanceMethod");
        OpenInstanceDel openDel = delMethod.CreateDelegate<OpenInstanceDel>();
        MethodInfo mi = openDel.Method;
....

    delegate void OpenInstanceDel(ref OpenInstanceDelStruct<int> del);

    struct OpenInstanceDelStruct<T>
    {
        public void InstanceMethod() { }
    }
}

which also repros in v8 and v7.

[steveharter]

I moved this to Future; SingleAccretion is there priority for addressing this?

[SingleAccretion]

is there priority for addressing this?

Nothing in particular. I have just noticed this bug while working on stack trace support downstream.