ICE: diagnostic.rs panics due to index out of bounds error

[0x1cedc0ffee]

I was experimenting with macros on a dummy project of mine. After doing something stupid I recieved this message:

 ➜  src git:(master) ✗ cargo test                                              
   Compiling libstuff v0.0.1 (file:///home/cake/projects/libstuff)
/home/cake/projects/libstuff/src/suffix.rs:53:35: 53:41 error: cannot borrow `*suffix` as immutable because it is also borrowed as mutable
/home/cake/projects/libstuff/src/suffix.rs:53             mutate_char!(suffix->[suffix.char_len() - 1] = mutation);
                                                                                 ^~~~~~
/home/cake/projects/libstuff/src/common.rs:21:1: 28:2 note: in expansion of mutate_char!
/home/cake/projects/libstuff/src/suffix.rs:53:13: 53:70 note: expansion site
/home/cake/projects/libstuff/src/suffix.rs:53:26: 53:32 note: previous borrow of `*suffix` occurs here; the mutable borrow prevents subsequent moves, borrows, or modification of `*suffix` until the borrow ends
/home/cake/projects/libstuff/src/suffix.rs:53             mutate_char!(suffix->[suffix.char_len() - 1] = mutation);
                                                                        ^~~~~~
/home/cake/projects/libstuff/src/common.rs:21:1: 28:2 note: in expansion of mutate_char!
/home/cake/projects/libstuff/src/suffix.rs:53:13: 53:70 note: expansion site
/home/cake/projects/libstuff/src/common.rs:24:35: 24:35 note: previous borrow ends here
/home/cake/projects/libstuff/src/suffix.rs:53:35: 53:41 error: cannot borrow `*suffix` as immutable because it is also borrowed as mutable
/home/cake/projects/libstuff/src/suffix.rs:53             mutate_char!(suffix->[suffix.char_len() - 1] = mutation);
                                                                                 ^~~~~~
/home/cake/projects/libstuff/src/common.rs:21:1: 28:2 note: in expansion of mutate_char!
/home/cake/projects/libstuff/src/suffix.rs:53:13: 53:70 note: expansion site
/home/cake/projects/libstuff/src/suffix.rs:53:26: 53:32 note: previous borrow of `*suffix` occurs here; the mutable borrow prevents subsequent moves, borrows, or modification of `*suffix` until the borrow ends
error: internal compiler error: unexpected panic
/home/cake/projects/libstuff/src/suffix.rs:53             mutate_char!(suffix->[suffix.char_len() - 1] = mutation);
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
/home/cake/projects/libstuff/src/common.rs:21:1: 28:2 note: in expansion of mutate_char!
/home/cake/projects/libstuff/src/suffix.rs:53:13: 53:70 note: expansion site
/home/cake/projects/libstuff/src/common.rs:24:35: 24:35 note: previous borrow ends here
task 'rustc' panicked at 'index out of bounds: the len is 0 but the index is 4294967295', /home/rustbuild/src/rust-buildbot/slave/nightly-linux/build/src/libsyntax/diagnostic.rs:535

stack backtrace:
   1: 0xb71fab50 - rt::backtrace::imp::write::ha919104d3a2cc2d39ay
   2: 0xb71fd9d0 - failure::on_fail::hc1b4eecd3de36abczDy
   3: 0xb706d550 - unwind::begin_unwind_inner::hb8ade4b3c397e25d6Qc
   4: 0xb706d170 - unwind::begin_unwind_fmt::h96b3ecc0c9195862hOc
   5: 0xb706d110 - rust_begin_unwind
   6: 0xb70b7fc0 - panicking::panic_fmt::h954780ce7200e90bVXl
   7: 0xb70be750 - panicking::panic_bounds_check::hf8e9aa67b630c0a4tWl
   8: 0xb59734a0 - diagnostic::emit::ha133b318627bd6d5oCG
   9: 0xb5970250 - diagnostic::EmitterWriter.Emitter::custom_emit::h219dee222ab8e3dbvAG
  10: 0xb596eda0 - diagnostic::SpanHandler::span_end_note::h07d1c89382f3eb8365F
  11: 0xb617ccd0 - middle::borrowck::check_loans::CheckLoanCtxt<'a, 'tcx>::report_error_if_loan_conflicts_with_restriction::hf5390e53f971a3a9lpd
  12: 0xb617c2d0 - middle::borrowck::check_loans::CheckLoanCtxt<'a, 'tcx>::report_error_if_loans_conflict::he4b6f11c9a52f8e4rmd
  13: 0xb617c220 - middle::borrowck::check_loans::CheckLoanCtxt<'a, 'tcx>::check_for_conflicting_loans::closure.93330
  14: 0xb617b940 - middle::borrowck::check_loans::CheckLoanCtxt<'a, 'tcx>::each_issued_loan::closure.93302
  15: 0xb617a9f0 - middle::dataflow::DataFlowContext<'a, 'tcx, O>::each_bit_for_node::h2757123354813815921
  16: 0xb617a630 - middle::borrowck::check_loans::CheckLoanCtxt<'a, 'tcx>::each_issued_loan::h15ff3291d452c8edDcd
  17: 0xb6168a80 - middle::borrowck::check_loans::CheckLoanCtxt<'a, 'tcx>.euv..Delegate<'tcx>::borrow::h5a6a3537b8882e35EZc
  18: 0xb6172e00 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'tcx, TYPER>::walk_expr::h6597893224547873452
  19: 0xb6178e90 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'tcx, TYPER>::consume_expr::h8888979236244829760
  20: 0xb6172e00 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'tcx, TYPER>::walk_expr::h6597893224547873452
  21: 0xb6178e90 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'tcx, TYPER>::consume_expr::h8888979236244829760
  22: 0xb6172e00 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'tcx, TYPER>::walk_expr::h6597893224547873452
  23: 0xb6178e90 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'tcx, TYPER>::consume_expr::h8888979236244829760
  24: 0xb6172e00 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'tcx, TYPER>::walk_expr::h6597893224547873452
  25: 0xb6178e90 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'tcx, TYPER>::consume_expr::h8888979236244829760
  26: 0xb6172a30 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'tcx, TYPER>::walk_block::h7708675825477625079
  27: 0xb6172e00 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'tcx, TYPER>::walk_expr::h6597893224547873452
  28: 0xb6178e90 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'tcx, TYPER>::consume_expr::h8888979236244829760
  29: 0xb6172a30 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'tcx, TYPER>::walk_block::h7708675825477625079
  30: 0xb6172e00 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'tcx, TYPER>::walk_expr::h6597893224547873452
  31: 0xb6178e90 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'tcx, TYPER>::consume_expr::h8888979236244829760
  32: 0xb6172a30 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'tcx, TYPER>::walk_block::h7708675825477625079
  33: 0xb616c0d0 - middle::borrowck::check_loans::check_loans::h03c8805865748350l6c
  34: 0xb61afe70 - middle::borrowck::borrowck_fn::h7bffaa42cc140af0Jli
  35: 0xb61b1ed0 - visit::walk_item::h8054865281593630383
  36: 0xb61b0e40 - visit::walk_mod::h11576973683542387380
  37: 0xb61b1ed0 - visit::walk_item::h8054865281593630383
  38: 0xb61b0e40 - visit::walk_mod::h11576973683542387380
  39: 0xb61b0890 - middle::borrowck::check_crate::ha9f42352a77d91e4fei
  40: 0xb766df00 - driver::driver::phase_3_run_analysis_passes::closure.58445
  41: 0xb74633a0 - util::common::time::h13760200948250138612
  42: 0xb76095f0 - driver::driver::phase_3_run_analysis_passes::h82d85a20fe7af3b07mS
  43: 0xb75fdfe0 - driver::driver::compile_input::he7a063ddc92829ca73R
  44: 0xb76833c0 - driver::run_compiler::h592ab58384c3f9d5n2T
  45: 0xb76832a0 - driver::run::closure.60785
  46: 0xb747bb50 - task::TaskBuilder::try_future::closure.39742
  47: 0xb71ce980 - task::TaskBuilder::spawn_internal::closure.30929
  48: 0xb706b350 - task::Task::spawn::closure.5761
  49: 0xb706cf40 - unwind::try::try_fn::hcc972c8eed9f09daDHc
  50: 0xb70ce440 - rust_try_inner
  51: 0xb70ce400 - rust_try
  52: 0xb706b430 - unwind::try::hd0fca846ae5e5c96pFc
  53: 0xb706b1e0 - task::Task::run::h4011677d931ed843fOb
  54: 0xb706add0 - task::Task::spawn::closure.5737
  55: 0xb706c760 - thread::thread_start::h1333e306c9ad24dci6b
  56: 0xb37d6c80 - start_thread
  57:        0x0 - <unknown>

Build failed, waiting for other jobs to finish...
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
task 'rustc' panicked at 'index out of bounds: the len is 0 but the index is 4294967295', /home/rustbuild/src/rust-buildbot/slave/nightly-linux/build/src/libsyntax/diagnostic.rs:535

stack backtrace:
   1: 0xb7201b50 - rt::backtrace::imp::write::ha919104d3a2cc2d39ay
   2: 0xb72049d0 - failure::on_fail::hc1b4eecd3de36abczDy
   3: 0xb7074550 - unwind::begin_unwind_inner::hb8ade4b3c397e25d6Qc
   4: 0xb7074170 - unwind::begin_unwind_fmt::h96b3ecc0c9195862hOc
   5: 0xb7074110 - rust_begin_unwind
   6: 0xb70befc0 - panicking::panic_fmt::h954780ce7200e90bVXl
   7: 0xb70c5750 - panicking::panic_bounds_check::hf8e9aa67b630c0a4tWl
   8: 0xb597a4a0 - diagnostic::emit::ha133b318627bd6d5oCG
   9: 0xb5977250 - diagnostic::EmitterWriter.Emitter::custom_emit::h219dee222ab8e3dbvAG
  10: 0xb5975da0 - diagnostic::SpanHandler::span_end_note::h07d1c89382f3eb8365F
  11: 0xb6183cd0 - middle::borrowck::check_loans::CheckLoanCtxt<'a, 'tcx>::report_error_if_loan_conflicts_with_restriction::hf5390e53f971a3a9lpd
  12: 0xb61832d0 - middle::borrowck::check_loans::CheckLoanCtxt<'a, 'tcx>::report_error_if_loans_conflict::he4b6f11c9a52f8e4rmd
  13: 0xb6183220 - middle::borrowck::check_loans::CheckLoanCtxt<'a, 'tcx>::check_for_conflicting_loans::closure.93330
  14: 0xb6182940 - middle::borrowck::check_loans::CheckLoanCtxt<'a, 'tcx>::each_issued_loan::closure.93302
  15: 0xb61819f0 - middle::dataflow::DataFlowContext<'a, 'tcx, O>::each_bit_for_node::h2757123354813815921
  16: 0xb6181630 - middle::borrowck::check_loans::CheckLoanCtxt<'a, 'tcx>::each_issued_loan::h15ff3291d452c8edDcd
  17: 0xb616fa80 - middle::borrowck::check_loans::CheckLoanCtxt<'a, 'tcx>.euv..Delegate<'tcx>::borrow::h5a6a3537b8882e35EZc
  18: 0xb6179e00 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'tcx, TYPER>::walk_expr::h6597893224547873452
  19: 0xb617fe90 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'tcx, TYPER>::consume_expr::h8888979236244829760
  20: 0xb6179e00 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'tcx, TYPER>::walk_expr::h6597893224547873452
  21: 0xb617fe90 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'tcx, TYPER>::consume_expr::h8888979236244829760
  22: 0xb6179e00 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'tcx, TYPER>::walk_expr::h6597893224547873452
  23: 0xb617fe90 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'tcx, TYPER>::consume_expr::h8888979236244829760
  24: 0xb6179e00 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'tcx, TYPER>::walk_expr::h6597893224547873452
  25: 0xb617fe90 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'tcx, TYPER>::consume_expr::h8888979236244829760
  26: 0xb6179a30 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'tcx, TYPER>::walk_block::h7708675825477625079
  27: 0xb6179e00 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'tcx, TYPER>::walk_expr::h6597893224547873452
  28: 0xb617fe90 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'tcx, TYPER>::consume_expr::h8888979236244829760
  29: 0xb6179a30 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'tcx, TYPER>::walk_block::h7708675825477625079
  30: 0xb6179e00 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'tcx, TYPER>::walk_expr::h6597893224547873452
  31: 0xb617fe90 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'tcx, TYPER>::consume_expr::h8888979236244829760
  32: 0xb6179a30 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'tcx, TYPER>::walk_block::h7708675825477625079
  33: 0xb61730d0 - middle::borrowck::check_loans::check_loans::h03c8805865748350l6c
  34: 0xb61b6e70 - middle::borrowck::borrowck_fn::h7bffaa42cc140af0Jli
  35: 0xb61b8ed0 - visit::walk_item::h8054865281593630383
  36: 0xb61b7e40 - visit::walk_mod::h11576973683542387380
  37: 0xb61b8ed0 - visit::walk_item::h8054865281593630383
  38: 0xb61b7e40 - visit::walk_mod::h11576973683542387380
  39: 0xb61b7890 - middle::borrowck::check_crate::ha9f42352a77d91e4fei
  40: 0xb7674f00 - driver::driver::phase_3_run_analysis_passes::closure.58445
  41: 0xb746a3a0 - util::common::time::h13760200948250138612
  42: 0xb76105f0 - driver::driver::phase_3_run_analysis_passes::h82d85a20fe7af3b07mS
  43: 0xb7604fe0 - driver::driver::compile_input::he7a063ddc92829ca73R
  44: 0xb768a3c0 - driver::run_compiler::h592ab58384c3f9d5n2T
  45: 0xb768a2a0 - driver::run::closure.60785
  46: 0xb7482b50 - task::TaskBuilder::try_future::closure.39742
  47: 0xb71d5980 - task::TaskBuilder::spawn_internal::closure.30929
  48: 0xb7072350 - task::Task::spawn::closure.5761
  49: 0xb7073f40 - unwind::try::try_fn::hcc972c8eed9f09daDHc
  50: 0xb70d5440 - rust_try_inner
  51: 0xb70d5400 - rust_try
  52: 0xb7072430 - unwind::try::hd0fca846ae5e5c96pFc
  53: 0xb70721e0 - task::Task::run::h4011677d931ed843fOb
  54: 0xb7071dd0 - task::Task::spawn::closure.5737
  55: 0xb7073760 - thread::thread_start::h1333e306c9ad24dci6b
  56: 0xb37ddc80 - start_thread
  57:        0x0 - <unknown>

Could not compile `libstuff`.

To learn more, run the command again with --verbose.
➜  src git:(master) ✗ rustc --version=verbose
rustc 0.13.0-nightly (5484d6f6d 2014-12-02 00:22:00 +0000)
binary: rustc
commit-hash: 5484d6f6d2844e9c52d42db52a1ba94739e10996
commit-date: 2014-12-02 00:22:00 +0000
host: i686-unknown-linux-gnu
release: 0.13.0-nightly

This seems to be the guilty line: https://github.com/rust-lang/rust/blob/master/src/libsyntax/diagnostic.rs#L535

Also, as you can see I am running the latest rust, installed using rustup.sh

Hope someone with better skill sets can determine the reason and submit a fix, though it looks like a minor issue.

[tamird]

@0x1cedc0ffee can you include your code that triggers this?

[steveklabnik]

Without a reproduction, we can't fix. @0x1cedc0ffee , please let us know if you are still having this problem, and can share the code that reproduces it.