ICE: Cannot relate bound region with for and unboxed closures.

[reem]

ICE:

/Users/reem/code/rust/rust-repro/src/lib.rs:13:20: 13:22 error: internal compiler error: cannot relate bound region: ReLateBound(40, BrNamed(DefId { krate: 0, node: 38 }, 'a)) <= '_#2r
/Users/reem/code/rust/rust-repro/src/lib.rs:13         self.call((st,))
                                                                  ^~
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:121

stack backtrace:
   1:        0x10b66c672 - rt::backtrace::imp::write::hbf3dc1e7a4bb0d9fE2s
   2:        0x10b66f81d - failure::on_fail::h19f3f29325059492Fjt
   3:        0x10b8eb8b5 - unwind::begin_unwind_inner::h11f1f10f7191e04ft2c
   4:        0x109603c07 - unwind::begin_unwind::h299357788950154889
   5:        0x109603ba0 - unwind::begin_unwind::h299357788950154889
   6:        0x1088e600a - middle::typeck::infer::region_inference::RegionVarBindings<'a, 'tcx>::make_subregion::h59221b14a213bbc58je
   7:        0x1088f5b9a - middle::typeck::infer::sub::Sub<'f, 'tcx>.Combine<'tcx>::regions::hcbc885f277691bbakSg
   8:        0x1088f58a1 - middle::typeck::infer::sub::Sub<'f, 'tcx>.Combine<'tcx>::contraregions::h7b9c530cae6cb51bKRg
   9:        0x10889c4ac - middle::typeck::infer::sub::Sub<'f, 'tcx>.Combine<'tcx>::tys::h1cd882cb6c9606fb8Zg
  10:        0x10889acee - middle::typeck::infer::coercion::Coerce<'f, 'tcx>::coerce_borrowed_pointer::h60419d2a00735497PU7
  11:        0x10889b34a - middle::typeck::infer::coercion::Coerce<'f, 'tcx>::tys::closure.132651
  12:        0x1088991ba - middle::typeck::infer::coercion::Coerce<'f, 'tcx>::unpack_actual_value::h4042172820200503477
  13:        0x108898fd3 - middle::typeck::infer::coercion::Coerce<'f, 'tcx>::tys::h9098822f957304c3YK7
  14:        0x108903181 - middle::typeck::infer::mk_coercety::closure.134484
  15:        0x108902e7b - middle::typeck::infer::InferCtxt<'a, 'tcx>::commit_if_ok::closure.134476
  16:        0x108902ce2 - middle::typeck::infer::InferCtxt<'a, 'tcx>::commit_unconditionally::h17169791873739487760
  17:        0x1086346df - middle::typeck::infer::mk_coercety::h9fe4bb253c411c79G8j
  18:        0x1087db447 - middle::typeck::check::FnCtxt<'a, 'tcx>::mk_assignty::h5d05f779d9dfa5f0I5Z
  19:        0x1087db285 - middle::typeck::check::demand::coerce::h00e3266736ea9a4fbuT
  20:        0x1088488b9 - middle::typeck::check::check_expr_coercable_to_type::closure.131680
  21:        0x1088460ef - middle::typeck::check::check_expr_with_unifier::h9f8a1b9246334edaoq1
  22:        0x108841e8f - middle::typeck::check::check_expr_with_unifier::h9f8a1b9246334edaoq1
  23:        0x10883eaeb - middle::typeck::check::check_argument_types::hdde5a55181e96ca6ES0
  24:        0x10883b307 - middle::typeck::check::check_method_argument_types::hbe01bcd7c2ac7829PQ0
  25:        0x108843e16 - middle::typeck::check::check_expr_with_unifier::h9f8a1b9246334edaoq1
  26:        0x108805f5f - middle::typeck::check::check_block_with_expected::hfd5adc8884f64ab0IB3
  27:        0x108802ed2 - middle::typeck::check::check_fn::h31448f7d3789f96aZ1X
  28:        0x1088023df - middle::typeck::check::check_bare_fn::h79542489bbb1565eaRX
  29:        0x108808773 - middle::typeck::check::check_method_body::h6674c67abbf753e8jmY
  30:        0x1087ff658 - middle::typeck::check::check_item::h0097c5bb8cb1a848rbY
  31:        0x108802230 - middle::typeck::check::check_item_types::h2eb061d653faf420kQX
  32:        0x10830b986 - util::common::time::h2485648588351033804
  33:        0x108b0b81e - middle::typeck::check_crate::h2980e0b15cfc487a9qr
  34:        0x108b73581 - driver::driver::phase_3_run_analysis_passes::h03ee8ebbed83e7c75gE
  35:        0x108b6d61b - driver::driver::compile_input::h87fe1ab3dfcd86abPXD
  36:        0x108bee225 - driver::run_compiler::h86282bff4e2aa57ckTH
  37:        0x108bec93e - driver::run::closure.144477
  38:        0x10832438b - task::TaskBuilder<S>::try_future::closure.103151
  39:        0x108324283 - task::TaskBuilder<S>::spawn_internal::closure.103122
  40:        0x1082de7bd - task::NativeSpawner.Spawner::spawn::closure.2484
  41:        0x10b94e5ec - rust_try_inner
  42:        0x10b94e5d6 - rust_try
  43:        0x10b8e9057 - unwind::try::h0c66ac3a369bbdae5Qc
  44:        0x10b8e8eec - task::Task::run::h9e20478d3c24ce75S2b
  45:        0x1082de5e3 - task::NativeSpawner.Spawner::spawn::closure.2408
  46:        0x10b8ea727 - thread::thread_start::heb03c58cfc9b7ebfYnc
  47:     0x7fff8a5022fc - _pthread_body
  48:     0x7fff8a502279 - _pthread_body

Reproduce:

pub trait Handler {
    fn handle(&self, &mut String);
}

impl<F> Handler for F
where F: for<'a, 'b> Fn(&'a mut String) {
    fn handle(&self, st: &mut String) {
        self.call((st,))
    }
}

Rustc version:

rustc 0.13.0-nightly (336349c93 2014-11-17 20:37:19 +0000)