internal compiler error: coherence failed to report ambiguity

[paulosuzart]

Hi,

this happens both with beta version and to nightly version 1.0.0-nightly (083b8a404 2015-04-05) (built 2015-04-05).

This issue #23037 is open at rust repo. Not sure if the lib authors can solve alone.

src/router.rs:158:1: 158:45 error: internal compiler error: coherence failed to report ambiguity: cannot locate the impl of the trait `core::marker::MarkerTrait` for the type `iron::middleware::Handler`
src/router.rs:158 impl Key for Router { type Value = Params; }
                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports
note: run with `RUST_BACKTRACE=1` for a backtrace
thread 'rustc' panicked at 'Box<Any>', /home/rustbuild/src/rust-buildbot/slave/nightly-dist-rustc-linux/build/src/libsyntax/diagnostic.rs:130

stack backtrace:
   1:     0x7fb7a59807b8 - sys::backtrace::write::h4618bbda30a2c1fakHC
   2:     0x7fb7a59abb87 - panicking::on_panic::h94b32ff0a2406463uUI
   3:     0x7fb7a58e3893 - rt::unwind::begin_unwind_inner::h310b6bce2d1d1820CzI
   4:     0x7fb7a2c8af1d - rt::unwind::begin_unwind::h11208009626465183390
   5:     0x7fb7a2c8aec3 - diagnostic::SpanHandler::span_bug::he0c1a59febe6c207YmB
   6:     0x7fb7a385106d - middle::traits::error_reporting::report_fulfillment_error::h978d9d7604a71a71FQN
   7:     0x7fb7a36cf1c1 - middle::traits::error_reporting::report_fulfillment_errors::hecc972a8fd21c54dVPN
   8:     0x7fb7a45c65ec - check::vtable::select_all_fcx_obligations_or_error::haf7db39d8950f48dX1b
   9:     0x7fb7a4650389 - check::wf::CheckTypeWellFormedVisitor<'ccx, 'tcx>::check_item_well_formed::h857600b69cfccd2amWk
  10:     0x7fb7a4658b52 - visit::walk_item::h9604823204726736875
  11:     0x7fb7a4752ec9 - check_crate::closure.36365
  12:     0x7fb7a474d473 - check_crate::hda9802680caa3ff01oC
  13:     0x7fb7a6000efd - driver::phase_3_run_analysis_passes::h763b1cd8b2718376gGa
  14:     0x7fb7a5fe4d55 - driver::compile_input::hd78076fc32781e7dQba
  15:     0x7fb7a609c3c5 - run_compiler::hff161264a18135f2S4b
  16:     0x7fb7a6099cdd - boxed::F.FnBox<A>::call_box::h610426945469311335
  17:     0x7fb7a6099219 - rt::unwind::try::try_fn::h14135578949834830543
  18:     0x7fb7a5a28338 - rust_try_inner
  19:     0x7fb7a5a28325 - rust_try
  20:     0x7fb7a60994eb - boxed::F.FnBox<A>::call_box::h11897562677317506333
  21:     0x7fb7a5996b71 - sys::thread::create::thread_start::h0a2c84bef4c472f7MuH
  22:     0x7fb79f76a181 - start_thread
  23:     0x7fb7a554647c - __clone
  24:                0x0 - <unknown>

Could not compile `router`.

Bests

[gsingh93]

This is a bug with Rust, not the router package. The patch for the bug is being reviewed and should be merged in the next day or two.

[gsingh93]

Try with the latest nightly, this should be fixed.

[reem]

It is.

EDIT: To be clear, I actually changed some code to make this work, I'm not sure if the ICE is actually fixed.