nox

error: internal compiler error: src/librustc/infer/region_inference/mod.rs:744: cannot relate bound region: '_#0r <= ReLateBound(DebruijnIndex { depth: 1 }, BrAnon(0))

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: run with `RUST_BACKTRACE=1` for a backtrace

thread 'rustc' panicked at 'Box<Any>', src/librustc_errors/lib.rs:611
stack backtrace:
   1:        0x112dd5578 - std::sys::backtrace::tracing::imp::write::he09d58d1497100a9
   2:        0x112de2edf - std::panicking::default_hook::{{closure}}::hf3f7aa526824ae88
   3:        0x112de02b5 - std::panicking::default_hook::h691f7ee16f920a74
   4:        0x112de09d6 - std::panicking::rust_panic_with_hook::haa794968064098e8
   5:        0x11011358b - std::panicking::begin_panic::hf274f14bdb87fcbf
   6:        0x11038d033 - rustc::session::opt_span_bug_fmt::{{closure}}::h5dd672376874cd4a
   7:        0x1102bd769 - rustc::session::opt_span_bug_fmt::hc5c69a270c708691
   8:        0x1102bd577 - rustc::session::span_bug_fmt::h3aa9210108db3097
   9:        0x11021b7d4 - rustc::infer::region_inference::RegionVarBindings::make_subregion::h93ed4765f004611a
  10:        0x110225176 - <rustc::infer::sub::Sub<'combine, 'infcx, 'gcx, 'tcx> as rustc::ty::relate::TypeRelation<'infcx, 'gcx, 'tcx>>::relate_with_variance::h0d4aeef760bbd016
  11:        0x110317700 - rustc::ty::relate::super_relate_tys::h2022942fa30528d7
  12:        0x1102256e6 - <rustc::infer::sub::Sub<'combine, 'infcx, 'gcx, 'tcx> as rustc::ty::relate::TypeRelation<'infcx, 'gcx, 'tcx>>::tys::h2bf89eb10a9d1e6f
  13:        0x1102297fe - rustc::infer::InferCtxt::sub::hfeaeb686490284f3
  14:        0x110230db3 - rustc::infer::InferCtxt::can_sub_types::hfaf5c719ab494fc4
  15:        0x10fb965b0 - rustc_typeck::check::method::<impl rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx>>::impl_or_return_item::hddfa8ddde664f1f7
  16:        0x10fb88707 - rustc_typeck::check::method::probe::ProbeContext::assemble_inherent_impl_probe::hfb5e2cd03e45b4a0
  17:        0x10fb88690 - rustc_typeck::check::method::probe::ProbeContext::assemble_inherent_impl_candidates_for_type::h709d22153c2adb9f
  18:        0x10fc317d6 - rustc_typeck::check::method::probe::<impl rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx>>::_probe::{{closure}}::h336b5c2a0d934142
  19:        0x10fb87e9b - rustc_typeck::check::method::probe::<impl rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx>>::_probe::h9110cca3e039ab3f
  20:        0x10fb8251f - rustc_typeck::check::demand::<impl rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx>>::demand_coerce::h5657bd1621a34100
  21:        0x10fbecca8 - rustc_typeck::check::FnCtxt::check_decl_initializer::h86d6287f9e226cfe
  22:        0x10fbecd46 - rustc_typeck::check::FnCtxt::check_decl_local::h8e99ebc1fe1fe246
  23:        0x10fbecf5d - rustc_typeck::check::FnCtxt::check_stmt::h0a2801a9369bf649
  24:        0x10fbed39a - rustc_typeck::check::FnCtxt::check_block_with_expected::h9cedf30c38bd09fc
  25:        0x10fbbe6eb - rustc_typeck::check::check_fn::h48704665f765c734
  26:        0x10fbbceb6 - rustc_typeck::check::check_bare_fn::hc4249ac71c21c813
  27:        0x10fbc02f5 - rustc_typeck::check::check_item_body::hbcf00db3a3807973
  28:        0x10fbbae15 - rustc_typeck::check::check_item_bodies::he2ef92955a881b4b
  29:        0x10fc23867 - rustc_typeck::check_crate::hbed19a7d1ad8d4e8
  30:        0x10f39551c - rustc_driver::driver::phase_3_run_analysis_passes::{{closure}}::h7ce10fd09281598f
  31:        0x10f363c64 - rustc_driver::driver::phase_3_run_analysis_passes::he8ee46117275842d
  32:        0x10f34ce6e - rustc_driver::driver::compile_input::h0271fc4a3333b327
  33:        0x10f376109 - rustc_driver::run_compiler::h1315ba568dec0ab8
  34:        0x10f2b7e28 - std::panicking::try::do_call::h10f47cce5c9324d1
  35:        0x112de349a - __rust_maybe_catch_panic
  36:        0x10f2d64cf - <F as alloc::boxed::FnBox<A>>::call_box::ha787c4c8ae12fdd8
  37:        0x112ddf574 - std::sys::thread::Thread::new::thread_start::h2d239c26e84b740e
  38:     0x7fff968b499c - _pthread_body
  39:     0x7fff968b4919 - _pthread_start