ICE with lifetimes in generic default methods

[carllerche]

Not exactly sure what the minimal failing test case is yet.

error: internal compiler error: unexpected failure
note: the compiler hit an unexpected failure path. this is a bug.
note: we would appreciate a bug report: http://static.rust-lang.org/doc/master/complement-bugreport.html
note: run with `RUST_BACKTRACE=1` for a backtrace
task 'rustc' failed at 'OwnedSlice: index out of bounds', /Users/carllerche/Code/oss/rust/src/libstd/option.rs:245
stack backtrace:
   1:        0x10c904d44 - rt::backtrace::imp::write::h561905b05278d6a1p8b::v0.10.pre
   2:        0x10c868f96 - rt::unwind::begin_unwind_inner::hda870342e18ba7c6TIb::v0.10.pre
   3:        0x1099f79a8 - rt::unwind::begin_unwind::h2e9e620644e625a9Ufr::v0.10.pre
   4:        0x109ba197c - middle::subst::ty..Region.Subst::subst_spanned::hafbe75f2b264bc4cB1R::v0.10.pre
   5:        0x109ba1cbc - middle::ty_fold::super_fold_sty::hfc1e43770e7f0d16lyR::v0.10.pre
   6:        0x109ba1293 - middle::subst::SubstFolder$LT$$x27a$GT$.TypeFolder::fold_ty::he9aa66e8dd4bec304LR::v0.10.pre
   7:        0x109b6a5c5 - middle::subst::ty..t.Subst::subst_spanned::hfef2031e6fd85109gKR::v0.10.pre
   8:        0x109a63783 - middle::subst::ty..substs.Subst::subst_spanned::hef6840c283de9d3cGWR::v0.10.pre
   9:        0x109b80045 - middle::subst::_$SP$T.Subst::subst_spanned::he352143217d87cf9HUR::v0.10.pre
  10:        0x109ba2bac - middle::subst::Vec$LT$T$GT$.Subst::subst_spanned::h7a9857957be41586vSR::v0.10.pre
  11:        0x109ba2e99 - middle::subst::ty..TypeParameterDef.Subst::subst_spanned::h876498d43b710aacEZR::v0.10.pre
  12:        0x109ba36b9 - middle::subst::Rc$LT$T$GT$.Subst::subst_spanned::h4e952c126f698753hTR::v0.10.pre
  13:        0x109ba3097 - middle::subst::ty..Generics.Subst::subst_spanned::h3db8a831718b4dfau0R::v0.10.pre
  14:        0x109d9542c - middle::typeck::coherence::CoherenceChecker$LT$$x27a$GT$::check_implementation::h8cf669eddb04046f4Zr::v0.10.pre
  15:        0x109d94029 - middle::typeck::coherence::CoherenceCheckVisitor$LT$$x27a$GT$.visit..Visitor$LT$$LP$$RP$$GT$::visit_item::h8b083113a4441edecWr::v0.10.pre
  16:        0x109d94901 - middle::typeck::coherence::CoherenceCheckVisitor$LT$$x27a$GT$.visit..Visitor$LT$$LP$$RP$$GT$::visit_item::h8b083113a4441edecWr::v0.10.pre
  17:        0x109da0211 - middle::typeck::coherence::check_coherence::hce2bf3bb6cab6432uKs::v0.10.pre
  18:        0x109db2a8f - util::common::time::hbc09d756ba2aa4cbwIh::v0.10.pre
  19:        0x109db18b1 - middle::typeck::check_crate::hf9819e1c3379e4f5YTu::v0.10.pre
  20:        0x10a1c2135 - driver::driver::phase_3_run_analysis_passes::h7847587d3ac359526xf::v0.10.pre
  21:        0x10a1c8423 - driver::driver::compile_input::hb54a51743aeaaa393Wf::v0.10.pre
  22:        0x10a1ee0e4 - run_compiler::h1e92e1871c644e1dxAn::v0.10.pre
  23:        0x10a201d8d - main_args::closure.92068
  24:        0x10a2005a2 - monitor::closure.91953
  25:        0x10a1fc14b - task::TaskBuilder::try::closure.91728
  26:        0x10c7ed49c - task::spawn_opts::closure.7957
  27:        0x10c900168 - rt::task::Task::run::closure.41637
  28:        0x10c90ab5c - rust_try
  29:        0x10c8fffe7 - rt::task::Task::run::h71f777d9db75993fWB9::v0.10.pre
  30:        0x10c7ed31f - task::spawn_opts::closure.7929
  31:        0x10c903726 - rt::thread::thread_start::h64defda557fd4656Dga::v0.10.pre
  32:     0x7fff8f23b772 - _pthread_start

$rustc --version
rustc 0.10-pre (d79fbba 2014-03-29 18:56:36 -0700)
host: x86_64-apple-darwin

[carllerche]

I think that I was running an out of date rustc. I don't think that this is a problem on master.

[carllerche]

Actually, I hit this on rustc that I just built from master.

[huonw]

I talked to @carllerche and he gave me access to his codebase, which I used to narrow down:

pub trait Foo {
  fn bar<'a, I: Iterator<&'a ()>>(&mut self, _: I) {}
}

pub struct Baz;

impl Foo for Baz {}

fn main() {}

Converting bar to a normal trait method and implementing it for Baz stops the ICE.

cc @pnkfelix