thread 'rustc' panicked at 'index out of bounds: the len is 0 but the index is 0'

[mediremi]

While cargo was compiling traverse, I encountered the error thread 'rustc' panicked at 'index out of bounds: the len is 0 but the index is 0'.

$ uname -rsm
Linux 3.13.0-24-generic x86_64

$ rustc --version --verbose
rustc 1.0.0-dev
binary: rustc
commit-hash: unknown
commit-date: unknown
host: x86_64-unknown-linux-gnu
release: 1.0.0-dev

Compiling traverse v0.0.6
error: internal compiler error: unexpected panic
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
thread 'rustc' panicked at 'index out of bounds: the len is 0 but the index is 0', /build/buildd/rust-nightly-201501310408~1d00c54~trusty/src/librustc/middle/infer/region_inference/mod.rs:1015

Backtrace:

stack backtrace:
   1:     0x7f52fa93e4d0 - sys::backtrace::write::hab6dd99acb511764H8t
   2:     0x7f52fa961840 - <unknown>
   3:     0x7f52fa8cde50 - rt::unwind::begin_unwind_inner::h3266fe1d96f60e3fAZA
   4:     0x7f52fa8ce970 - rt::unwind::begin_unwind_fmt::he5da4c6aaeb74bfa6XA
   5:     0x7f52fa9616a0 - rust_begin_unwind
   6:     0x7f52fa9a9a50 - panicking::panic_fmt::h18479da70a65102cARv
   7:     0x7f52fa9b2120 - panicking::panic_bounds_check::h3eb82e89c0e73253BQv
   8:     0x7f52f8ab4000 - <unknown>
   9:     0x7f52f8ab3c90 - middle::infer::region_inference::RegionVarBindings<'a, 'tcx>::resolve_regions::hf123a4c5108ce144Yyv
  10:     0x7f52f8ad3400 - middle::infer::InferCtxt<'a, 'tcx>::resolve_regions_and_report_errors::h70d3d0c25f8018a9d8z
  11:     0x7f52fa0a61a0 - <unknown>
  12:     0x7f52fa0ae7d0 - <unknown>
  13:     0x7f52fa0b4e20 - <unknown>
  14:     0x7f52fa0b4e20 - <unknown>
  15:     0x7f52fa17e550 - <unknown>
  16:     0x7f52fa179030 - check_crate::hcad51444396ed313IEz
  17:     0x7f52faec7b70 - driver::phase_3_run_analysis_passes::h7f0251bcf43e0862NFa
  18:     0x7f52faeaef50 - driver::compile_input::h10073932bcf4c3a9Bba
  19:     0x7f52faf74f50 - <unknown>
  20:     0x7f52faf735e0 - <unknown>
  21:     0x7f52faf72510 - <unknown>
  22:     0x7f52fa9cbe80 - <unknown>
  23:     0x7f52fa9cbe70 - rust_try
  24:     0x7f52faf727c0 - <unknown>
  25:     0x7f52fa94e010 - <unknown>
  26:     0x7f52f4cb20c0 - start_thread
  27:     0x7f52fa54dec9 - __clone
  28:                0x0 - <unknown>

[renato-zannon]

Seems like a duplicate of #21750

[alexcrichton]

Thanks @renato-zannon!