ICE: `Cannot relate bound region`

[zslayton]

Ostensibly related to #10841 which was created 2 days prior.

Error:

simplejson.rs:45:7: 46:7 error: internal compiler error: Cannot relate bound region: ReInfer(60) <= ReLateBound(78, BrNamed(syntax::ast::DefId{crate: 0u32, node: 108u32}, a))
This message reflects a bug in the Rust compiler. 
We would appreciate a bug report: https://github.com/mozilla/rust/wiki/HOWTO-submit-a-Rust-bug-report
simplejson.rs:45                                                        map.find_nested(key_iterator)
simplejson.rs:46                                                },
task 'rustc' failed at 'explicit failure', /home/zslayton/rust/src/libsyntax/diagnostic.rs:76
task '<main>' failed at 'explicit failure', /home/zslayton/rust/src/librustc/lib.rs:393

Source: https://gist.github.com/zslayton/7867213

64-Bit Linux Mint
rustc 0.9-pre (a6310f6 2013-12-08 11:51:22 -0800)
host: x86_64-unknown-linux-gnu

[alexcrichton]

cc @nikomatsakis

[eminence]

I'm not sure if I'm running into the same issue, but if so I think I have a smaller reproducer for this:

trait Tag<'a> {
    fn get_name(&'a self) -> &'a str;
}

struct FooTag {
    _name: ~str
}
impl<'a> Tag<'a> for FooTag {
    fn get_name(&'a self) -> &'a str { self._name.as_slice() }
}

fn main() {
    let tag : ~Tag = ~FooTag {_name: ~"hello" } as ~Tag;
    let s = tag.get_name();

}

a.rs:14:12: 14:15 error: internal compiler error: Cannot relate bound region: ReEarlyBound(13, 0, a) <= ReInfer(3)
This message reflects a bug in the Rust compiler. 
We would appreciate a bug report: https://github.com/mozilla/rust/wiki/HOWTO-submit-a-Rust-bug-report
a.rs:14     let s = tag.get_name();

0.9-pre (aa4455e 2013-12-06 01:11:18 -0800)
host: x96_64 OSX 10.9

[nikomatsakis]

Dup #5121