ICE on rustc 1.26.0-nightly (ae544ee1c 2018-03-29)

[topecongiro]

I encountered an ICE while working on rustfmt (my branch) with this commit. I am using 1.26.0-nightly (ae544ee1c 2018-03-29).

Log

thread 'rustc' panicked at 'called `Result::unwrap()` on an `Err` value: (MoveData { move_paths: [MovePath { place: _0 }, MovePath { place: _1 }, MovePath { place: _2 }, MovePath { place: _3 }, MovePath { first_child: mp30, place: _4 }, MovePath { place: _5 }, MovePath { place: _6 }, MovePath { place: _7 }, MovePath { place: _8 }, MovePath { place: _9 }, MovePath { place: _10 }, MovePath { place: _11 }, MovePath { place: _12 }, MovePath { place: _13 }, MovePath { place: _14 }, MovePath { place: _15 }, MovePath { place: _16 }, MovePath { place: _17 }, MovePath { place: _18 }, MovePath { place: _19 }, MovePath { first_child: mp28, place: _20 }, MovePath { place: _21 }, MovePath { place: _22 }, MovePath { place: _23 }, MovePath { place: _24 }, MovePath { place: _25 }, MovePath { place: _26 }, MovePath { place: _27 }, MovePath { parent: mp20, place: (*_20) }, MovePath { parent: mp4, place: (_4.0: &'<empty> imports::UseSegment) }, MovePath { parent: mp4, next_sibling: mp29 place: (_4.1: &'<empty> &'<empty> mut imports::UseSegment) }], moves: [mp5@bb0[5], mp6@bb0[5], mp6@bb0[6], mp5@bb0[7], mp10@bb0[10], mp1@bb2[7], mp22@bb2[10], mp23@bb2[10], mp13@bb3[10], mp14@bb3[10], mp11@bb4[1], mp9@bb5[0], mp14@bb6[0], mp13@bb6[1], mp15@bb6[2], mp8@bb6[4], mp16@bb6[5], mp16@bb6[6], mp1@bb7[0], mp8@bb8[0], mp9@bb9[0], mp16@bb10[0], mp23@bb11[0], mp22@bb11[1], mp20@bb12[0], mp22@bb13[0], mp21@bb14[0], mp22@bb15[0], mp26@bb15[5], mp26@bb16[0], mp25@bb16[3], mp27@bb16[3], mp27@bb17[0], mp25@bb17[1], mp25@bb18[0], mp24@bb19[0], mp25@bb20[0], mp21@bb20[1], mp24@bb20[1], mp24@bb20[2], mp24@bb21[0], mp21@bb21[1], mp21@bb22[0], mp20@bb22[1], mp19@bb22[2], mp19@bb22[3], mp18@bb23[0], mp20@bb24[0], mp19@bb25[0], mp20@bb25[1], mp20@bb26[0], mp18@bb26[1], mp18@bb27[0], mp17@bb28[0], mp18@bb29[0], mp17@bb29[1], mp17@bb29[2], mp17@bb30[0], mp9@bb31[0], mp8@bb31[1], mp8@bb32[0], mp4@bb32[1], mp1@bb32[2], mp0@bb33[0]], loc_map: LocationMap { map: [[[], [], [], [], [], [mo0, mo1], [mo2], [mo3], [], [], [mo4]], [[]], [[], [], [], [], [], [], [], [mo5], [], [], [mo6, mo7]], [[], [], [], [], [], [], [], [], [], [], [mo8, mo9]], [[], [mo10]], [[mo11]], [[mo12], [mo13], [mo14], [], [mo15], [mo16], [mo17]], [[mo18]], [[mo19]], [[mo20]], [[mo21], []], [[mo22], [mo23]], [[mo24]], [[mo25]], [[mo26]], [[mo27], [], [], [], [], [mo28]], [[mo29], [], [], [mo30, mo31]], [[mo32], [mo33]], [[mo34]], [[mo35]], [[mo36], [mo37, mo38], [mo39]], [[mo40], [mo41]], [[mo42], [mo43], [mo44], [mo45]], [[mo46]], [[mo47]], [[mo48], [mo49]], [[mo50], [mo51]], [[mo52]], [[mo53]], [[mo54], [mo55], [mo56]], [[mo57], []], [[mo58], [mo59]], [[mo60], [mo61], [mo62]], [[mo63]]] }, path_map: [[mo63], [mo5, mo18, mo62], [], [], [mo61], [mo0, mo3], [mo1, mo2], [], [mo15, mo19, mo59, mo60], [mo11, mo20, mo58], [mo4], [mo10], [], [mo8, mo13], [mo9, mo12], [mo14], [mo16, mo17, mo21], [mo53, mo55, mo56, mo57], [mo46, mo51, mo52, mo54], [mo44, mo45, mo48], [mo24, mo43, mo47, mo49, mo50], [mo26, mo37, mo41, mo42], [mo6, mo23, mo25, mo27], [mo7, mo22], [mo35, mo38, mo39, mo40], [mo30, mo33, mo34, mo36], [mo28, mo29], [mo31, mo32], [], [], []], rev_lookup: MovePathLookup { locals: [mp0, mp1, mp2, mp3, mp4, mp5, mp6, mp7, mp8, mp9, mp10, mp11, mp12, mp13, mp14, mp15, mp16, mp17, mp18, mp19, mp20, mp21, mp22, mp23, mp24, mp25, mp26, mp27], projections: {(mp4, Field(field[1], AbstractType)): mp30, (mp20, Deref): mp28, (mp4, Field(field[0], AbstractType)): mp29} }, inits: [mp1@src/imports.rs:145:14: 145:18 (Deep), mp2@src/imports.rs:145:20: 145:25 (Deep), mp3@src/imports.rs:145:44: 145:48 (Deep), mp5@src/imports.rs:146:16: 146:21 (Deep), mp6@src/imports.rs:146:23: 146:29 (Deep), mp4@src/imports.rs:146:15: 146:30 (Deep), mp7@src/imports.rs:146:9: 155:10 (Deep), mp10@src/imports.rs:147:14: 147:38 (Deep), mp20@<vec macros>:3:25: 3:46 (Shallow), mp22@src/imports.rs:152:46: 152:50 (Deep), mp23@src/imports.rs:152:52: 152:56 (Deep), mp21@src/imports.rs:152:17: 152:57 (NonPanicPathOnly), mp8@src/imports.rs:147:31: 147:37 (Deep), mp9@src/imports.rs:147:57: 147:63 (Deep), mp13@src/imports.rs:148:17: 148:19 (Deep), mp15@src/imports.rs:148:27: 148:34 (Deep), mp14@src/imports.rs:148:27: 148:34 (Deep), mp12@src/imports.rs:148:17: 148:35 (NonPanicPathOnly), mp11@src/imports.rs:147:40: 147:64 (Deep), mp16@src/imports.rs:149:34: 149:36 (Deep), mp0@src/imports.rs:149:17: 149:37 (Deep), mp26@src/imports.rs:153:46: 153:51 (Deep), mp25@src/imports.rs:153:46: 153:59 (NonPanicPathOnly), mp27@src/imports.rs:153:61: 153:65 (Deep), mp24@src/imports.rs:153:17: 153:66 (NonPanicPathOnly), mp28@<vec macros>:3:29: 3:46 (Deep), mp19@<vec macros>:3:25: 3:46 (Deep), mp18@<vec macros>:3:25: 3:46 (Deep), mp17@<vec macros>:3:1: 3:48 (NonPanicPathOnly), mp0@src/imports.rs:151:18: 154:15 (Deep)], init_loc_map: LocationMap { map: [[[], [], [in3], [], [in4], [in5], [], [], [in6], [in7], []], [[]], [[], [], [], [], [in8], [], [], [in9], [], [in10], [in11]], [[], [in12], [], [in13], [], [in14], [], [], [in15], [in16], [in17]], [[in18], []], [[]], [[], [], [], [], [in19], [in20], []], [[]], [[]], [[]], [[], []], [[], []], [[]], [[]], [[]], [[], [], [], [], [in21], [in22]], [[], [], [in23], [in24]], [[], []], [[]], [[]], [[], [in25], []], [[], []], [[], [in26], [in27], []], [[]], [[]], [[], []], [[], [in28]], [[]], [[]], [[], [in29], []], [[], []], [[], []], [[], [], []], [[]]] }, init_path_map: [[in20, in29], [in0], [in1], [in2], [in5], [in3], [in4], [in6], [in12], [in13], [in7], [in18], [in17], [in14], [in16], [in15], [in19], [in28], [in27], [in26], [in8], [in11], [in9], [in10], [in24], [in22], [in21], [in23], [in25], [], []] }, [IllegalMove { cannot_move_out_of: IllegalMoveOrigin { span: src/imports.rs:147:31: 147:37, kind: BorrowedContent } }, IllegalMove { cannot_move_out_of: IllegalMoveOrigin { span: src/imports.rs:147:57: 147:63, kind: BorrowedContent } }])', libcore/result.rs:945:5

Backtrace

   0: std::sys::unix::backtrace::tracing::imp::unwind_backtrace
             at libstd/sys/unix/backtrace/tracing/gcc_s.rs:49
   1: std::sys_common::backtrace::print
             at libstd/sys_common/backtrace.rs:71
             at libstd/sys_common/backtrace.rs:59
   2: std::panicking::default_hook::{{closure}}
             at libstd/panicking.rs:207
   3: std::panicking::default_hook
             at libstd/panicking.rs:223
   4: core::ops::function::Fn::call
   5: std::panicking::rust_panic_with_hook
             at libstd/panicking.rs:403
   6: std::panicking::begin_panic_fmt
             at libstd/panicking.rs:349
   7: rust_begin_unwind
             at libstd/panicking.rs:325
   8: core::panicking::panic_fmt
             at libcore/panicking.rs:72
   9: core::result::unwrap_failed
  10: <rustc_mir::transform::elaborate_drops::ElaborateDrops as rustc_mir::transform::MirPass>::run_pass
  11: rustc_mir::transform::optimized_mir::{{closure}}
  12: rustc_mir::transform::optimized_mir
  13: rustc::ty::maps::<impl rustc::ty::maps::queries::optimized_mir<'tcx>>::compute_result
  14: rustc::dep_graph::graph::DepGraph::with_task_impl
  15: rustc_errors::Handler::track_diagnostics
  16: rustc::ty::maps::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::cycle_check
  17: rustc::ty::maps::<impl rustc::ty::maps::queries::optimized_mir<'tcx>>::force
  18: rustc::ty::maps::<impl rustc::ty::maps::queries::optimized_mir<'tcx>>::try_get
  19: rustc::ty::maps::TyCtxtAt::optimized_mir
  20: rustc::ty::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::instance_mir
  21: rustc_mir::monomorphize::collector::collect_items_rec
  22: rustc_mir::monomorphize::collector::collect_items_rec
  23: rustc_mir::monomorphize::collector::collect_items_rec
  24: rustc_mir::monomorphize::collector::collect_items_rec
  25: rustc_mir::monomorphize::collector::collect_items_rec
  26: rustc_mir::monomorphize::collector::collect_items_rec
  27: rustc_mir::monomorphize::collector::collect_items_rec
  28: rustc_mir::monomorphize::collector::collect_items_rec
  29: rustc_mir::monomorphize::collector::collect_items_rec
  30: rustc_mir::monomorphize::collector::collect_items_rec
  31: rustc_mir::monomorphize::collector::collect_items_rec
  32: rustc_mir::monomorphize::collector::collect_items_rec
  33: rustc_mir::monomorphize::collector::collect_items_rec
  34: rustc_mir::monomorphize::collector::collect_items_rec
  35: rustc_mir::monomorphize::collector::collect_items_rec
  36: rustc_mir::monomorphize::collector::collect_items_rec
  37: rustc_mir::monomorphize::collector::collect_items_rec
  38: rustc_mir::monomorphize::collector::collect_items_rec
  39: rustc_mir::monomorphize::collector::collect_crate_mono_items
  40: rustc::util::common::time
  41: rustc_trans::base::collect_and_partition_translation_items
  42: rustc::dep_graph::graph::DepGraph::with_task_impl
  43: rustc_errors::Handler::track_diagnostics
  44: rustc::ty::maps::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::cycle_check
  45: rustc::ty::maps::<impl rustc::ty::maps::queries::collect_and_partition_translation_items<'tcx>>::force
  46: rustc::ty::maps::<impl rustc::ty::maps::queries::collect_and_partition_translation_items<'tcx>>::try_get
  47: rustc::ty::maps::TyCtxtAt::collect_and_partition_translation_items
  48: rustc::ty::maps::<impl rustc::ty::context::TyCtxt<'a, 'tcx, 'lcx>>::collect_and_partition_translation_items
  49: rustc_trans::base::trans_crate
  50: <rustc_trans::LlvmTransCrate as rustc_trans_utils::trans_crate::TransCrate>::trans_crate
  51: rustc::util::common::time
  52: rustc_driver::driver::phase_4_translate_to_llvm
  53: rustc_driver::driver::compile_input::{{closure}}
  54: <std::thread::local::LocalKey<T>>::with
  55: <std::thread::local::LocalKey<T>>::with
  56: rustc::ty::context::TyCtxt::create_and_enter
  57: rustc_driver::driver::compile_input
  58: rustc_driver::run_compiler_impl
  59: syntax::with_globals

[ishitatsuyuki]

Can you try a few older nightlies to determine which day has this regressed? Looks similar to #46197, so maybe you can check that thread as well.

[ishitatsuyuki]

From #50668: this has also regressed stable.

[nikomatsakis]

@topecongiro perhaps you can https://github.com/rust-lang-nursery/cargo-bisect-rustc to nail down more precisely what led to the problem? if so, that would be 💯!

[nikomatsakis]

I'll assign to myself but mostly trying to veirfy if this is indeed a dup of #46197 to start

[Swoorup]

I wonder if this is something a beginner can solve, since this looks like a regression? If so, I can take a look?

[ishitatsuyuki]

@Swoorup #49534 (comment) has some instructions for what you can start with, but actually fixing the root cause may be hard. Either way, if you report back the team members will answer your questions.

[nikomatsakis]

Note that #46197 -- of which this is possibly a dup -- was itself a dup of another issue, which has been fixed. So it's possible that there is no bug here (but in that case, the original source should now fail to compile with a compilation error).

Can anyone verify that? (cc @topecongiro)

[mikhail-m1]

looking at it

[mikhail-m1]

it successfully compiles by rustc 1.28.0-nightly (2a00629 2018-06-09), of cause after several fixes not related to the ICE commit.

[nikomatsakis]

@mikhail-m1 to be clear, you mean that the specific commit of rustfmt is working now? In other words, the ICE is gone? In that case, we can probably close, even if we don't know the exact cause.

[mikhail-m1]

yes, it works, I think it's enough for close

[Swoorup]

Still crashing using this code on playground on nightly
https://play.rust-lang.org/?gist=f0fb16a9c07eaa29468da07063225642&version=nightly&mode=debug

[mikhail-m1]

thanks for nice sample, stack backtrace is same, I will look at it, minimized:

fn main() {
    let a = vec!["".to_string()];
    a.iter().enumerate()
            .take_while(|(_, &t)| false)
            .collect::<Vec<_>>();
}

[nikomatsakis]

This might be fixed by #51686

[nikomatsakis]

Yes, it is.