No compiler error when attempting to use voidptr as type argument

[Choosechee]

Using voidptr as a type argument does not cause a compiler error, even though it is invalid and causes a BadImageFormatException or TypeLoadException at runtime.

Repro steps

1. Use voidptr as a type argument, e.g:

let badList: voidptr list = []
printf "%A" badList

2. Compile.

Expected behavior

An error, preventing compilation. This happens in C# with void*.

Actual behavior

No compilation error, but errors at runtime.

Known workarounds

Don't try to use voidptr as a generic type argument.

Related information

• Operating system: Kubuntu 25.10
• .NET Runtime kind: .NET 10
• Editing Tools: JetBrains Rider 2025.3.1

[Choosechee]

I have discovered that this also happens with ilsigptr.