Recursive type with a legal Zero value fails to compile

[brianberns]

Consider the following code:

type Foo<'t when 't : (static member Zero : 't)> =
    | MkFoo of 't

type Bar =
    | Nil
    | MkBar of Foo<Bar>   // Error: The type 'Bar' does not support the operator 'get_Zero'

    static member Zero
        with get () = Nil

let zeroBar = LanguagePrimitives.GenericZero<Bar>   // this compiles fine, so Bar definitely has a legal Zero value

Expected behavior

Should compile with no problems.

Actual behavior

Compiler error: The type 'Bar' does not support the operator 'get_Zero'

Known workarounds

None

[dsyme]

Yes, this is a bug in phasing in the type checker, thank you. The union cases are being checked before the methods are created, hence the constraint failure. It's a tricky problem in the multiple phases in establishing types