rustc panic from unwrapping None #67200

thread 'rustc' panicked at 'called `Option::unwrap()` on a `None` value', src/libcore/option.rs:378:21
stack backtrace:
   0:     0x7ff0ab81eaf4 - backtrace::backtrace::libunwind::trace::hda41dbcdfba36aa0
                               at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.37/src/backtrace/libunwind.rs:88
   1:     0x7ff0ab81eaf4 - backtrace::backtrace::trace_unsynchronized::h1a8d6e1f8cb3f5d4
                               at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.37/src/backtrace/mod.rs:66
   2:     0x7ff0ab81eaf4 - std::sys_common::backtrace::_print_fmt::h610c4127487e10da
                               at src/libstd/sys_common/backtrace.rs:76
   3:     0x7ff0ab81eaf4 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h0722dc552e01bd1d
                               at src/libstd/sys_common/backtrace.rs:60
   4:     0x7ff0ab85712c - core::fmt::write::h01edf6dd68a42c9c
                               at src/libcore/fmt/mod.rs:1030
   5:     0x7ff0ab812d17 - std::io::Write::write_fmt::hf15985f193f03c04
                               at src/libstd/io/mod.rs:1412
   6:     0x7ff0ab823325 - std::sys_common::backtrace::_print::hd8d5d08a1795e743
                               at src/libstd/sys_common/backtrace.rs:64
   7:     0x7ff0ab823325 - std::sys_common::backtrace::print::hf89a79e3921a2366
                               at src/libstd/sys_common/backtrace.rs:49
   8:     0x7ff0ab823325 - std::panicking::default_hook::{{closure}}::h3a8f42beb3bb8ae3
                               at src/libstd/panicking.rs:196
   9:     0x7ff0ab823016 - std::panicking::default_hook::h8f803b0bc31a5c37
                               at src/libstd/panicking.rs:210
  10:     0x7ff0abd5a483 - rustc_driver::report_ice::he98718c53edc6d3d
  11:     0x7ff0ab823b0c - std::panicking::rust_panic_with_hook::h825f041245da8739
                               at src/libstd/panicking.rs:477
  12:     0x7ff0ab8235c2 - std::panicking::continue_panic_fmt::hbe0378e33481e81b
                               at src/libstd/panicking.rs:380
  13:     0x7ff0ab8234b6 - rust_begin_unwind
                               at src/libstd/panicking.rs:307
  14:     0x7ff0ab850aca - core::panicking::panic_fmt::h527855ce0bc891f6
                               at src/libcore/panicking.rs:85
  15:     0x7ff0ab850a09 - core::panicking::panic::h2f49f09cf859b728
                               at src/libcore/panicking.rs:49
  16:     0x7ff0ac2d7fc4 - rustc_typeck::check::typeck_tables_of::h7e98a74ad7491971
  17:     0x7ff0ac3294ca - rustc::ty::query::__query_compute::typeck_tables_of::h8235d6e55b8e3584
  18:     0x7ff0ac3c315b - rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::typeck_tables_of>::compute::hef02a238f3e43402
  19:     0x7ff0ac367cc2 - rustc::dep_graph::graph::DepGraph::with_task_impl::hd911b0f10264fdeb
  20:     0x7ff0ac442551 - rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query::hfde020d3574d1a10
  21:     0x7ff0ad5d95eb - rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::typeck_tables_of>::compute::hef02a238f3e43402
  22:     0x7ff0ad15529e - rustc::dep_graph::graph::DepGraph::with_task_impl::he7e3c2c275ef2244
  23:     0x7ff0ad4a557a - rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query::h903a5be3e2161c0c
  24:     0x7ff0ad3a738d - rustc::traits::error_reporting::<impl rustc::infer::InferCtxt>::note_obligation_cause::h2c6cdc829848b452
  25:     0x7ff0ad39f28b - rustc::traits::error_reporting::<impl rustc::infer::InferCtxt>::report_selection_error::he0ecf9fe84056058
  26:     0x7ff0ad397a7c - rustc::traits::error_reporting::<impl rustc::infer::InferCtxt>::report_fulfillment_errors::hbfaf98e94c81acbb
  27:     0x7ff0ac2e57c1 - rustc_typeck::check::FnCtxt::resolve_generator_interiors::hb97defff881a87da
  28:     0x7ff0ac4518ae - rustc::ty::context::GlobalCtxt::enter_local::hee87012a37ec7481
  29:     0x7ff0ac2d7ea2 - rustc_typeck::check::typeck_tables_of::h7e98a74ad7491971
  30:     0x7ff0ac3294ca - rustc::ty::query::__query_compute::typeck_tables_of::h8235d6e55b8e3584
  31:     0x7ff0ac3c315b - rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::typeck_tables_of>::compute::hef02a238f3e43402
  32:     0x7ff0ac367cc2 - rustc::dep_graph::graph::DepGraph::with_task_impl::hd911b0f10264fdeb
  33:     0x7ff0ac442551 - rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query::hfde020d3574d1a10
  34:     0x7ff0ac3294ca - rustc::ty::query::__query_compute::typeck_tables_of::h8235d6e55b8e3584
  35:     0x7ff0ac3c315b - rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::typeck_tables_of>::compute::hef02a238f3e43402
  36:     0x7ff0ac367cc2 - rustc::dep_graph::graph::DepGraph::with_task_impl::hd911b0f10264fdeb
  37:     0x7ff0ac442551 - rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query::hfde020d3574d1a10
  38:     0x7ff0ac4880ae - rustc_typeck::collect::checked_type_of::hd3908c8eaed72ecd
  39:     0x7ff0ac4877dc - rustc_typeck::collect::type_of::h799e995bf65f21ec
  40:     0x7ff0ac32b0b7 - rustc::ty::query::__query_compute::type_of::hb01507aa4b57e392
  41:     0x7ff0ac3c2e5b - rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::type_of>::compute::hd6cd78f07fee48ed
  42:     0x7ff0ac365052 - rustc::dep_graph::graph::DepGraph::with_task_impl::hbdb7bb8db373711b
  43:     0x7ff0ac3d2a04 - rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query::h0ad13fb369585832
  44:     0x7ff0ac4a6bf0 - rustc::hir::intravisit::walk_expr::hf4b6465856d88960
  45:     0x7ff0ac466f2c - rustc::hir::intravisit::Visitor::visit_fn::hd86c16bc3957ea4d
  46:     0x7ff0ac4a92f9 - rustc::hir::intravisit::walk_item::h2499ad75ffa206ec
  47:     0x7ff0ac48375d - <rustc_typeck::collect::CollectItemTypesVisitor as rustc::hir::intravisit::Visitor>::visit_item::h6ecf11c5154ce45d
  48:     0x7ff0ac32e103 - rustc::hir::map::Map::visit_item_likes_in_module::h6cf58cf1c61058c9
  49:     0x7ff0ac483424 - rustc_typeck::collect::collect_mod_item_types::ha8af4c2694cae051
  50:     0x7ff0ac32a44a - rustc::ty::query::__query_compute::collect_mod_item_types::h0959d140ce4a445c
  51:     0x7ff0ac3c334b - rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::collect_mod_item_types>::compute::hcc8bedd87b11d3e0
  52:     0x7ff0ac356f57 - rustc::dep_graph::graph::DepGraph::with_task_impl::h1149bcd7b6e6f8f9
  53:     0x7ff0ac3e51f8 - rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query::h1ad8f3fe22fc6341
  54:     0x7ff0ac34e23d - rustc_typeck::check_crate::{{closure}}::{{closure}}::hef852192e4b21571
  55:     0x7ff0ac32e766 - rustc::util::common::time::h6c804872fd5ef88f
  56:     0x7ff0ac4fe3fc - rustc_typeck::check_crate::h2e77f97476aecad8
  57:     0x7ff0abe0900a - rustc_interface::passes::analysis::h7d37d49a7360493d
  58:     0x7ff0abd1cc01 - rustc::ty::query::__query_compute::analysis::h1c5cc76ea5bb496b
  59:     0x7ff0abd05322 - rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query::hcf7bc9d073dcb36b
  60:     0x7ff0abd2442a - rustc_interface::passes::BoxedGlobalCtxt::access::{{closure}}::h7fc0f9f179325408
  61:     0x7ff0abe851da - rustc_interface::passes::create_global_ctxt::{{closure}}::h10595b15ffb5db35
  62:     0x7ff0abd2664e - rustc_interface::interface::run_compiler_in_existing_thread_pool::ha009ae4607895a11
  63:     0x7ff0abd5c362 - std::thread::local::LocalKey<T>::with::h30eaff0b6e71bc49
  64:     0x7ff0abd613ce - scoped_tls::ScopedKey<T>::set::h6ab0051cc42102a7
  65:     0x7ff0abd821a2 - syntax::with_globals::h9994c1c3242d3263
  66:     0x7ff0abceee10 - std::sys_common::backtrace::__rust_begin_short_backtrace::h229c554686840b66
  67:     0x7ff0ab83425a - __rust_maybe_catch_panic
                               at src/libpanic_unwind/lib.rs:80
  68:     0x7ff0abd18879 - core::ops::function::FnOnce::call_once{{vtable.shim}}::hf2e117c529f2753f
  69:     0x7ff0ab8051ff - <alloc::boxed::Box<F> as core::ops::function::FnOnce<A>>::call_once::h483711add4ba2330
                               at /rustc/4560ea788cb760f0a34127156c78e2552949f734/src/liballoc/boxed.rs:922
  70:     0x7ff0ab832f00 - <alloc::boxed::Box<F> as core::ops::function::FnOnce<A>>::call_once::h7605b45eb29ed0be
                               at /rustc/4560ea788cb760f0a34127156c78e2552949f734/src/liballoc/boxed.rs:922
  71:     0x7ff0ab832f00 - std::sys_common::thread::start_thread::h557b0c2dc4449562
                               at src/libstd/sys_common/thread.rs:13
  72:     0x7ff0ab832f00 - std::sys::unix::thread::Thread::new::thread_start::h7c2a7f9b68fe4bba
                               at src/libstd/sys/unix/thread.rs:79
  73:     0x7ff0ab5976ba - start_thread
  74:     0x7ff0aaea741d - clone
  75:                0x0 - <unknown>

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 1.39.0 (4560ea788 2019-11-04) running on x86_64-unknown-linux-gnu

note: compiler flags: -C debuginfo=2 -C ar=arm-linux-gnueabihf-gcc-ar-4.7 -C linker=arm-linux-gnueabihf-g++-4.7 -C incremental --crate-type bin

note: some of the compiler flags provided by cargo are hidden