ICE on stable 1.26 and nightly 1.27

[Swoorup]

For some reason, the following example fails to compile resulting in ICE.

I have tested on the latest stable 1.26 and nightly.

https://play.rust-lang.org/?gist=5cc063593994ef7a0ee52b298c83116b&version=stable&mode=debug

RUST_BACKTRACE=1 output on 1.27 nightly:

thread 'main' 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 { place: _4 }, MovePath { place: _5 }, MovePath { place: _6 }, MovePath { place: _7 }, MovePath { place: _8 }], moves: [mp7@bb0[10], mp7@bb2[1], mp4@bb2[2], mp5@bb2[2], mp3@bb3[0], mp5@bb4[0], mp6@bb4[1], mp6@bb5[0], mp6@bb6[0], mp8@bb6[1], mp4@bb6[2], mp3@bb6[3], mp3@bb7[0], mp0@bb7[1]], loc_map: LocationMap { map: [[[], [], [], [], [], [], [], [], [], [], [mo0]], [[]], [[], [mo1], [mo2, mo3]], [[mo4]], [[mo5], [mo6]], [[mo7]], [[mo8], [mo9], [mo10], [mo11]], [[mo12], [mo13]]] }, path_map: [[mo13], [], [], [mo4, mo11, mo12], [mo2, mo10], [mo3, mo5], [mo6, mo7, mo8], [mo0, mo1], [mo9]], rev_lookup: MovePathLookup { locals: [mp0, mp1, mp2, mp3, mp4, mp5, mp6, mp7, mp8], projections: {} }, inits: [mp1@ice.rs:9:40: 9:72 (Deep), mp2@ice.rs:9:41: 9:48 (Deep), mp3@ice.rs:9:46: 9:47 (Deep), mp4@ice.rs:9:50: 9:51 (Deep), mp8@ice.rs:9:55: 9:60 (Deep), mp7@ice.rs:9:55: 9:60 (Deep), mp6@ice.rs:9:55: 9:72 (NonPanicPathOnly), mp5@ice.rs:9:55: 9:72 (Deep), mp0@ice.rs:9:50: 9:72 (NonPanicPathOnly)], init_loc_map: LocationMap { map: [[[], [in2], [], [in3], [], [], [], [], [in4], [in5], [in6]], [[]], [[in7], [], [in8]], [[]], [[], []], [[]], [[], [], [], []], [[], []]] }, init_path_map: [[in8], [in0], [in1], [in2], [in3], [in7], [in6], [in5], [in4]] }, [IllegalMove { cannot_move_out_of: IllegalMoveOrigin { span: ice.rs:9:46: 9:47, kind: BorrowedContent } }])', libcore/result.rs:945:5
stack backtrace:
   0: std::sys::unix::backtrace::tracing::imp::unwind_backtrace
   1: std::sys_common::backtrace::print
   2: std::panicking::default_hook::{{closure}}
   3: std::panicking::default_hook
   4: rustc::util::common::panic_hook
   5: std::panicking::rust_panic_with_hook
   6: std::panicking::begin_panic_fmt
   7: rust_begin_unwind
   8: core::panicking::panic_fmt
   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::config::QueryConfig<'tcx> for rustc::ty::maps::queries::optimized_mir<'tcx>>::compute
  14: rustc::dep_graph::graph::DepGraph::with_task_impl
  15: rustc::ty::context::tls::with_related_context
  16: rustc::ty::maps::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::force_query_with_job
  17: rustc::ty::maps::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::get_query
  18: rustc::ty::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::instance_mir
  19: rustc_mir::monomorphize::collector::collect_items_rec
  20: rustc_mir::monomorphize::collector::collect_items_rec
  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_crate_mono_items
  28: rustc::util::common::time
  29: rustc_trans::base::collect_and_partition_translation_items
  30: rustc::dep_graph::graph::DepGraph::with_task_impl
  31: rustc::ty::context::tls::with_related_context
  32: rustc::ty::maps::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::force_query_with_job
  33: rustc::ty::maps::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::get_query
  34: rustc_trans::base::trans_crate
  35: <rustc_trans::LlvmTransCrate as rustc_trans_utils::trans_crate::TransCrate>::trans_crate
  36: rustc::util::common::time
  37: rustc_driver::driver::phase_4_translate_to_llvm
  38: rustc_driver::driver::compile_input::{{closure}}
  39: rustc::ty::context::tls::enter_context
  40: <std::thread::local::LocalKey<T>>::with
  41: rustc::ty::context::TyCtxt::create_and_enter
  42: rustc_driver::driver::compile_input
  43: rustc_driver::run_compiler_impl
  44: <scoped_tls::ScopedKey<T>>::set
  45: syntax::with_globals
  46: <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once
  47: __rust_maybe_catch_panic
  48: rustc_driver::run
  49: rustc_driver::main
  50: std::rt::lang_start::{{closure}}
  51: std::panicking::try::do_call
  52: __rust_maybe_catch_panic
  53: std::rt::lang_start_internal
  54: main
query stack during panic:
#0 [optimized_mir] processing `main::{{closure}}`
#1 [collect_and_partition_translation_items] collect_and_partition_translation_items
end of query stack

error: internal compiler error: unexpected panic

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: rustc 1.27.0-nightly (acd3871ba 2018-05-10) running on x86_64-apple-darwin

[durka]

Looks like a duplicate of #49534.

[Swoorup]

Looks like NLL allows the compiler to report the error correctly:

https://play.rust-lang.org/?gist=598a3b5c5359d4b9d72099a20d8219b4&version=nightly&mode=debug

[ishitatsuyuki]

Closing this in favour of #49534.