Error choosing among several implementations of a trait's static method

[burg]

It seems that rustc isn't able to choose among multiple impls, and insists that some arbitrary one is the "right" one. (Note that type parameters are explicit to work around #3902)

Testcase

mod base {
    trait HasNew<T> {
        static pure fn new() -> T;
    }

    pub struct Foo {
        dummy: (),
    }

    pub impl Foo : HasNew<Foo> {
        static pure fn new() -> Foo {
            Foo { dummy: () }
        }
    }

    pub struct Bar {
        dummy: (),
    }

    pub impl Bar : HasNew<Bar> {
        static pure fn new() -> Bar {
            Bar { dummy: () }
        }
    }
}

fn main() {
    let f: base::Foo = base::new::<base::Foo, base::Foo>();
    debug!("%?", f);
}

Error

[burg@host-5-178 Desktop]# rustc test.rs
test.rs:28:23: 28:56 error: mismatched types: expected `@base::HasNew<base::Bar>` but found `@base::HasNew<base::Foo>` (expected class base::Bar but found class base::Foo)
test.rs:28     let f: base::Foo = base::new::<base::Foo, base::Foo>();
                                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
test.rs:28:23: 28:56 error: mismatched types: expected `base::Foo` but found `base::Bar` (expected class base::Foo but found class base::Bar)
test.rs:28     let f: base::Foo = base::new::<base::Foo, base::Foo>();
                                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
test.rs:28:23: 28:56 error: mismatched types: expected `@base::HasNew<base::Bar>` but found `@base::HasNew<base::Foo>` (expected class base::Bar but found class base::Foo)
test.rs:28     let f: base::Foo = base::new::<base::Foo, base::Foo>();
                                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
test.rs:28:23: 28:56 error: mismatched types: expected `base::Foo` but found `base::Bar` (expected class base::Foo but found class base::Bar)
test.rs:28     let f: base::Foo = base::new::<base::Foo, base::Foo>();
                                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~