ICE in type checking.

[Kimundi]

Got no time right now to reduce my code to something suitable for this issue, but here's the stacktrace:

env RUST_BACKTRACE=1 rustc -Z time-passes --test lib.rs 
time: 0.021 s   parsing
time: 0.001 s   gated feature checking
time: 0.000 s   crate injection
time: 0.006 s   configuration 1
time: 0.004 s   plugin loading
time: 0.000 s   plugin registration
time: 0.153 s   expansion
time: 0.019 s   configuration 2
time: 0.041 s   maybe building test harness
time: 0.020 s   prelude injection
time: 0.024 s   assigning node ids and indexing ast
time: 0.003 s   checking that all macro invocations are gone
time: 0.007 s   external crate/lib resolution
time: 0.006 s   language item collection
time: 0.062 s   resolution
time: 0.003 s   lifetime resolution
time: 0.003 s   looking for entry point
time: 0.003 s   looking for plugin registrar
time: 0.004 s   freevar finding
time: 0.008 s   region resolution
time: 0.003 s   loop checking
time: 0.005 s   stability index
time: 0.010 s   type collecting
time: 0.006 s   variance inference
time: 0.051 s   coherence checking
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://doc.rust-lang.org/complement-bugreport.html
note: run with `RUST_BACKTRACE=1` for a backtrace
task 'rustc' failed at 'index out of bounds: the len is 0 but the index is 0', /build/rust-git/src/rust/src/librustc/middle/subst.rs:405

stack backtrace:
   1:     0x7fd5930924f0 - rt::backtrace::imp::write::he3c153cabf4a7f3cq3p
   2:     0x7fd593095d50 - <unknown>
   3:     0x7fd5938578a0 - unwind::begin_unwind_inner::ha5a65b58df160a4040d
   4:     0x7fd5938574f0 - unwind::begin_unwind_fmt::h70c2f259a714c416xYd
   5:     0x7fd5938574b0 - rust_begin_unwind
   6:     0x7fd593893040 - failure::begin_unwind::hbc3d32be3f0f0eadGsj
   7:     0x7fd5938968f0 - failure::fail_bounds_check::h8a8c6b47b9c92f81Sqj
   8:     0x7fd593fa7e60 - <unknown>
   9:     0x7fd593fa7e20 - <unknown>
  10:     0x7fd593fa6930 - <unknown>
  11:     0x7fd593fa6760 - <unknown>
  12:     0x7fd59410ffa0 - <unknown>
  13:     0x7fd5942507f0 - <unknown>
  14:     0x7fd59423bca0 - middle::typeck::check::check_item::h780bfe8df0600ffbKte
  15:     0x7fd594242850 - middle::typeck::check::check_item_types::ha8e05ac0096302bbRVd
  16:     0x7fd5943b4ad0 - <unknown>
  17:     0x7fd5943b37c0 - middle::typeck::check_crate::h402e13d36885c984UhE
  18:     0x7fd594780d90 - driver::driver::phase_3_run_analysis_passes::hb27e21c9fdbdedb5pIs
  19:     0x7fd59477c630 - driver::driver::compile_input::hf7d515d8bec94a4equs
  20:     0x7fd594833670 - <unknown>
  21:     0x7fd594833580 - <unknown>
  22:     0x7fd5948473d0 - <unknown>
  23:     0x7fd594847160 - <unknown>
  24:     0x7fd59688f510 - <unknown>
  25:     0x7fd5938a7040 - rust_try
  26:     0x7fd593854930 - unwind::try::h63746c58630b0ca2tPd
  27:     0x7fd593854690 - task::Task::run::h93b61e983904f1c5P0c
  28:     0x7fd59688f300 - <unknown>
  29:     0x7fd593856910 - <unknown>
  30:     0x7fd592b12060 - start_thread
  31:     0x7fd59351f489 - __clone
  32:                0x0 - <unknown>

[huonw]

(This is actually an ICE in the phase after coherence checking (i.e. type checking), since the timing is printed after each phase finishes; I have updated the title.)

[pczarn]

An example that gives the same exact "the len is 0 but the index is 0".

#![feature(overloaded_calls)]
use std::ops::{Fn, Add};
struct g;
impl<'a,A:Add<int,int>> Fn<(A,),int> for g {
    #[rust_call_abi_hack]
    fn call(&self, (arg,): (A,)) -> int {
        arg.add(&1)
    }
}
g(1i)

Edit: Unrelated. It has its own issue.

[ghost]

As we're missing the code to reproduce this issue, it's not really actionable, so I'm going to close it.