task 'rustc' failed at 'Box<Any>'

task 'rustc' failed at 'Box<Any>'

> export RUST_BACKTRACE=1; rustc bug.rs

error: internal compiler error: ID not mapped to struct fields: enum Two::Two (id=4)
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 'Box<Any>', /Users/dsyang/Sandbox/rustlang/src/libsyntax/diagnostic.rs:168

stack backtrace:
   1:        0x1063f92a8 - rt::backtrace::imp::write::h12b3324ffcfcdd502fq
   2:        0x1063fca95 - failure::on_fail::he36628f56c0f4863lwq
   3:        0x1066a61e9 - unwind::begin_unwind_inner::h8135dee5c8286a22AXd
   4:        0x105b39d05 - unwind::begin_unwind::h12569733258430280161
   5:        0x105b3a7f8 - diagnostic::Handler::bug::h58e97a721ad45ea5D7x
   6:        0x103426828 - driver::session::Session::bug::h91ab18a88f08487apas
   7:        0x1035d08f2 - middle::ty::lookup_struct_fields::hac7572be417da69e1vV
   8:        0x10349737a - middle::ty::struct_fields::hcb3cdd690e89ff167AV
   9:        0x1035ffb46 - middle::ty::type_contents::tc_ty::h6d775dc2c56185308GS
  10:        0x10359a8fd - middle::ty::type_contents::h09cb75c56e154ee94FS
  11:        0x103933dc7 - middle::kind::check_item::h4a32786748d2f540eMU
  12:        0x103935f61 - middle::kind::check_crate::h8d20f100eec1d176DCU
  13:        0x103c14e42 - driver::driver::phase_3_run_analysis_passes::heb010e46b316ca70f8q
  14:        0x103c0f991 - driver::driver::compile_input::h7196c79b698b7ccegUq
  15:        0x103cc1a68 - driver::run_compiler::hae5e32c0270c10d4jSt
  16:        0x103cbf0b6 - driver::main_args::closure.$x22closure$x22$LP$132056$RP$
  17:        0x103cd249b - task::TaskBuilder<S>::try_future::closure.$x22closure$x22$LP$133205$RP$
  18:        0x103cd2391 - task::TaskBuilder<S>::spawn_internal::closure.$x22closure$x22$LP$133182$RP$
  19:        0x1033c28cc - task::spawn_opts::closure.$x22closure$x22$LP$8260$RP$
  20:        0x106709e8c - rust_try
  21:        0x1066a2f4b - unwind::try::h22420274a0b3d039ZLd
  22:        0x1066a2cb3 - task::Task::run::h6be5360930724b3cRXc
  23:        0x1033c2761 - task::spawn_opts::closure.$x22closure$x22$LP$8205$RP$
  24:        0x1066a4f46 - thread::thread_start::h48e14365ddcec355pkd
  25:     0x7fff8a557899 - _pthread_body
  26:     0x7fff8a55772a - _pthread_struct_init