ICE: Type parameter out of range when substituting in region 'a

[thehydroimpulse]

ICE:

Users/daniel/Projects/rust/nanomsg.rs/src/lib.rs:1:1: 1:1 error: internal compiler error: Type parameter out of range when substituting in region 'a (root type='amut Socket<'a>) (space=FnSpace, index=1)
/Users/daniel/Projects/rust/nanomsg.rs/src/lib.rs:1 #![crate_type = "lib"]
                                                    ^
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: http://doc.rust-lang.org/complement-bugreport.html
note: run with `RUST_BACKTRACE=1` for a backtrace
task 'rustc' panicked at 'Box<Any>', /Users/rustbuild/src/rust-buildbot/slave/nightly-mac/build/src/libsyntax/diagnostic.rs:116

I have a struct S that takes lifetime 'a. Because the lifetime is associated with an unsafe pointer (technically, the implementation hides this). I added a ContravariantLifetime<'a> marker type.

pub struct Socket<'a> {
    value: c_int,
   marker: ContravariantLifetime<'a>
}

Now, Socket has a method called bind that creates a new Endpoint

pub struct Endpoint<'a> {
    socket: c_int,
    val: c_int,
    marker: ContravariantLifetime<'a>
}

impl<'a> Socket<'a> {
    pub fn bind<'b, 'a: 'b>(&'a mut self, addr: &str) -> Endpoint<'b> {
        // ...
    }
}

That is, I want a new lifetime 'b that is shorter than the lifetime of 'a.

Having the lifetime of 'a of &mut self results in the ICE, without it works fine.

/cc @aturon @nikomatsakis

[nikomatsakis]

Dup of #18232