ICE: `unexpected region: ReError`

[matthiaskrgr]

Code

rustc -Zdrop-tracking-mir=yes --edition=2021 treereduce.rs

use std::future::Future;

trait Client {
    type Connecting<'a>: Future + Send
    where
        Self: 'a;

    fn connect(&'_ self) -> Self::Connecting<'a>;
}

fn call_connect<C>(c: &'_ C) -> impl '_ + Future + Send
where
    C: Client + Send + Sync,
{
    async move { c.connect().await }
}

Meta

rustc --version --verbose:

rustc 1.71.0-nightly (c4190f2d3 2023-05-07)
binary: rustc
commit-hash: c4190f2d3a46a59f435f7b42f58bc22b2f4d6917
commit-date: 2023-05-07
host: x86_64-unknown-linux-gnu
release: 1.71.0-nightly
LLVM version: 16.0.2

Error output

<output>

Backtrace

error: internal compiler error: compiler/rustc_trait_selection/src/traits/select/mod.rs:3019:26: unexpected region: ReError

thread 'rustc' panicked at 'Box<dyn Any>', /rustc/c4190f2d3a46a59f435f7b42f58bc22b2f4d6917/compiler/rustc_errors/src/lib.rs:1650:9
stack backtrace:
   0:     0x7f22a7d69e71 - std::backtrace_rs::backtrace::libunwind::trace::hdca2f1d760ae3bfc
                               at /rustc/c4190f2d3a46a59f435f7b42f58bc22b2f4d6917/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5
   1:     0x7f22a7d69e71 - std::backtrace_rs::backtrace::trace_unsynchronized::hd02181015534cc1c
                               at /rustc/c4190f2d3a46a59f435f7b42f58bc22b2f4d6917/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7f22a7d69e71 - std::sys_common::backtrace::_print_fmt::h027d0dd83d9c6057
                               at /rustc/c4190f2d3a46a59f435f7b42f58bc22b2f4d6917/library/std/src/sys_common/backtrace.rs:65:5
   3:     0x7f22a7d69e71 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hc3454f8104aa16e4
                               at /rustc/c4190f2d3a46a59f435f7b42f58bc22b2f4d6917/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x7f22a7dca1bf - core::fmt::rt::Argument::fmt::haca00ab3f8062a1f
                               at /rustc/c4190f2d3a46a59f435f7b42f58bc22b2f4d6917/library/core/src/fmt/rt.rs:138:9
   5:     0x7f22a7dca1bf - core::fmt::write::he3e34afeea0f8a6d
                               at /rustc/c4190f2d3a46a59f435f7b42f58bc22b2f4d6917/library/core/src/fmt/mod.rs:1094:21
   6:     0x7f22a7d5d141 - std::io::Write::write_fmt::h0dda8fe866ff6ad9
                               at /rustc/c4190f2d3a46a59f435f7b42f58bc22b2f4d6917/library/std/src/io/mod.rs:1712:15
   7:     0x7f22a7d69c85 - std::sys_common::backtrace::_print::hdee7445a3e0bc35e
                               at /rustc/c4190f2d3a46a59f435f7b42f58bc22b2f4d6917/library/std/src/sys_common/backtrace.rs:47:5
   8:     0x7f22a7d69c85 - std::sys_common::backtrace::print::h88d45cc795ad4f3a
                               at /rustc/c4190f2d3a46a59f435f7b42f58bc22b2f4d6917/library/std/src/sys_common/backtrace.rs:34:9
   9:     0x7f22a7d6c917 - std::panicking::default_hook::{{closure}}::h0c28f70af069bb4e
  10:     0x7f22a7d6c704 - std::panicking::default_hook::h9d9751edb4b25952
                               at /rustc/c4190f2d3a46a59f435f7b42f58bc22b2f4d6917/library/std/src/panicking.rs:288:9
  11:     0x7f22aaf89e4b - rustc_driver_impl[dde0876b390e6a89]::install_ice_hook::{closure#0}
  12:     0x7f22a7d6d037 - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::hd829a428c0494b99
                               at /rustc/c4190f2d3a46a59f435f7b42f58bc22b2f4d6917/library/alloc/src/boxed.rs:1999:9
  13:     0x7f22a7d6d037 - std::panicking::rust_panic_with_hook::hb6e77b312dba3d0e
                               at /rustc/c4190f2d3a46a59f435f7b42f58bc22b2f4d6917/library/std/src/panicking.rs:695:13
  14:     0x7f22ab44e221 - std[d48aaa48ad184f7f]::panicking::begin_panic::<rustc_errors[f0db23b40a7f92ee]::ExplicitBug>::{closure#0}
  15:     0x7f22ab44de16 - std[d48aaa48ad184f7f]::sys_common::backtrace::__rust_end_short_backtrace::<std[d48aaa48ad184f7f]::panicking::begin_panic<rustc_errors[f0db23b40a7f92ee]::ExplicitBug>::{closure#0}, !>
  16:     0x7f22ab477ac6 - std[d48aaa48ad184f7f]::panicking::begin_panic::<rustc_errors[f0db23b40a7f92ee]::ExplicitBug>
  17:     0x7f22ab471ec4 - <rustc_errors[f0db23b40a7f92ee]::HandlerInner>::bug::<alloc[f90fa24b258e2697]::string::String>
  18:     0x7f22ab471bf6 - <rustc_errors[f0db23b40a7f92ee]::Handler>::bug::<alloc[f90fa24b258e2697]::string::String>
  19:     0x7f22ab4f9aac - rustc_middle[f12e14326fcb6d37]::util::bug::opt_span_bug_fmt::<rustc_span[3e163d59592952e6]::span_encoding::Span>::{closure#0}
  20:     0x7f22ab4f92da - rustc_middle[f12e14326fcb6d37]::ty::context::tls::with_opt::<rustc_middle[f12e14326fcb6d37]::util::bug::opt_span_bug_fmt<rustc_span[3e163d59592952e6]::span_encoding::Span>::{closure#0}, !>::{closure#0}
  21:     0x7f22ab4f92aa - rustc_middle[f12e14326fcb6d37]::ty::context::tls::with_context_opt::<rustc_middle[f12e14326fcb6d37]::ty::context::tls::with_opt<rustc_middle[f12e14326fcb6d37]::util::bug::opt_span_bug_fmt<rustc_span[3e163d59592952e6]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
  22:     0x7f22a919becd - rustc_middle[f12e14326fcb6d37]::util::bug::bug_fmt
  23:     0x7f22abbab674 - rustc_trait_selection[f271c5c5f9af5999]::traits::select::bind_generator_hidden_types_above::{closure#0}::{closure#1}::{closure#0}
  24:     0x7f22abb4fea2 - <rustc_middle[f12e14326fcb6d37]::ty::subst::GenericArg as rustc_type_ir[79abdb9a60271110]::fold::TypeFoldable<rustc_middle[f12e14326fcb6d37]::ty::context::TyCtxt>>::try_fold_with::<rustc_middle[f12e14326fcb6d37]::ty::fold::RegionFolder>
  25:     0x7f22abb04c0f - <&rustc_middle[f12e14326fcb6d37]::ty::list::List<rustc_middle[f12e14326fcb6d37]::ty::subst::GenericArg> as rustc_type_ir[79abdb9a60271110]::fold::TypeFoldable<rustc_middle[f12e14326fcb6d37]::ty::context::TyCtxt>>::try_fold_with::<rustc_middle[f12e14326fcb6d37]::ty::fold::RegionFolder>
  26:     0x7f22ababc596 - <rustc_middle[f12e14326fcb6d37]::ty::sty::AliasTy as rustc_type_ir[79abdb9a60271110]::fold::TypeFoldable<rustc_middle[f12e14326fcb6d37]::ty::context::TyCtxt>>::try_fold_with::<rustc_middle[f12e14326fcb6d37]::ty::fold::RegionFolder>
  27:     0x7f22abb3731a - <rustc_middle[f12e14326fcb6d37]::ty::Ty as rustc_type_ir[79abdb9a60271110]::fold::TypeSuperFoldable<rustc_middle[f12e14326fcb6d37]::ty::context::TyCtxt>>::super_fold_with::<rustc_middle[f12e14326fcb6d37]::ty::fold::RegionFolder>
  28:     0x7f22abba6f39 - <rustc_middle[f12e14326fcb6d37]::ty::context::TyCtxt>::fold_regions::<rustc_middle[f12e14326fcb6d37]::ty::Ty, rustc_trait_selection[f271c5c5f9af5999]::traits::select::bind_generator_hidden_types_above::{closure#0}::{closure#1}::{closure#0}>
  29:     0x7f22abba0e28 - <&mut rustc_trait_selection[f271c5c5f9af5999]::traits::select::bind_generator_hidden_types_above::{closure#0}::{closure#1} as core[1a45016e46435943]::ops::function::FnOnce<(rustc_middle[f12e14326fcb6d37]::ty::subst::EarlyBinder<rustc_middle[f12e14326fcb6d37]::ty::Ty>,)>>::call_once
  30:     0x7f22abafab3a - <alloc[f90fa24b258e2697]::vec::Vec<rustc_middle[f12e14326fcb6d37]::ty::Ty> as alloc[f90fa24b258e2697]::vec::spec_from_iter::SpecFromIter<rustc_middle[f12e14326fcb6d37]::ty::Ty, core[1a45016e46435943]::iter::adapters::map::Map<core[1a45016e46435943]::iter::adapters::filter::Filter<core[1a45016e46435943]::iter::adapters::map::Map<core[1a45016e46435943]::iter::adapters::filter::Filter<core[1a45016e46435943]::slice::iter::Iter<rustc_middle[f12e14326fcb6d37]::mir::query::GeneratorSavedTy>, <rustc_middle[f12e14326fcb6d37]::ty::context::TyCtxt>::generator_hidden_types::{closure#0}>, <rustc_middle[f12e14326fcb6d37]::ty::context::TyCtxt>::generator_hidden_types::{closure#1}>, rustc_trait_selection[f271c5c5f9af5999]::traits::select::bind_generator_hidden_types_above::{closure#0}::{closure#0}>, rustc_trait_selection[f271c5c5f9af5999]::traits::select::bind_generator_hidden_types_above::{closure#0}::{closure#1}>>>::from_iter
  31:     0x7f22abba3a44 - rustc_trait_selection[f271c5c5f9af5999]::traits::select::bind_generator_hidden_types_above
  32:     0x7f22a9198130 - <rustc_trait_selection[f271c5c5f9af5999]::traits::select::SelectionContext>::select
  33:     0x7f22a916aeb7 - <rustc_trait_selection[f271c5c5f9af5999]::traits::fulfill::FulfillProcessor as rustc_data_structures[e6a995bd1645ab1f]::obligation_forest::ObligationProcessor>::process_obligation
  34:     0x7f22a9168561 - <rustc_data_structures[e6a995bd1645ab1f]::obligation_forest::ObligationForest<rustc_trait_selection[f271c5c5f9af5999]::traits::fulfill::PendingPredicateObligation>>::process_obligations::<rustc_trait_selection[f271c5c5f9af5999]::traits::fulfill::FulfillProcessor>
  35:     0x7f22a931ceb2 - <rustc_trait_selection[f271c5c5f9af5999]::traits::engine::ObligationCtxt>::select_all_or_error
  36:     0x7f22a997e3f2 - rustc_trait_selection[f271c5c5f9af5999]::traits::query::type_op::custom::scrape_region_constraints::<rustc_borrowck[fe7f2bcff357714e]::type_check::InstantiateOpaqueType, (), <rustc_borrowck[fe7f2bcff357714e]::type_check::InstantiateOpaqueType as rustc_trait_selection[f271c5c5f9af5999]::traits::query::type_op::TypeOp>::fully_perform::{closure#0}>
  37:     0x7f22a997dac0 - <rustc_borrowck[fe7f2bcff357714e]::type_check::TypeChecker>::fully_perform_op::<(), rustc_borrowck[fe7f2bcff357714e]::type_check::InstantiateOpaqueType>
  38:     0x7f22a997c5fa - <rustc_infer[81cc4442e2774718]::infer::nll_relate::TypeRelating<rustc_borrowck[fe7f2bcff357714e]::type_check::relate_tys::NllTypeRelatingDelegate>>::relate_opaques
  39:     0x7f22a9955077 - <rustc_borrowck[fe7f2bcff357714e]::type_check::TypeChecker>::typeck_mir
  40:     0x7f22a98d3397 - rustc_borrowck[fe7f2bcff357714e]::nll::compute_regions
  41:     0x7f22a9880bec - rustc_borrowck[fe7f2bcff357714e]::do_mir_borrowck
  42:     0x7f22a987d36b - rustc_borrowck[fe7f2bcff357714e]::mir_borrowck
  43:     0x7f22a987b708 - rustc_query_system[284fc37ba8dbaa13]::query::plumbing::try_execute_query::<rustc_query_impl[14a35b422f4e9e94]::queries::mir_borrowck, rustc_query_impl[14a35b422f4e9e94]::plumbing::QueryCtxt>
  44:     0x7f22a987b3f0 - rustc_query_impl[14a35b422f4e9e94]::get_query::mir_borrowck
  45:     0x7f22aa340d7d - rustc_hir_analysis[df7ae5e86821b533]::collect::type_of::type_of
  46:     0x7f22a962641b - rustc_query_system[284fc37ba8dbaa13]::query::plumbing::try_execute_query::<rustc_query_impl[14a35b422f4e9e94]::queries::type_of, rustc_query_impl[14a35b422f4e9e94]::plumbing::QueryCtxt>
  47:     0x7f22a9625760 - rustc_query_impl[14a35b422f4e9e94]::get_query::type_of
  48:     0x7f22a9fb25e0 - rustc_middle[f12e14326fcb6d37]::ty::query::query_get_at::<rustc_query_system[284fc37ba8dbaa13]::query::caches::DefaultCache<rustc_span[3e163d59592952e6]::def_id::DefId, rustc_middle[f12e14326fcb6d37]::query::erase::Erased<[u8; 8usize]>>>
  49:     0x7f22a9faca09 - rustc_hir_analysis[df7ae5e86821b533]::check::check::check_mod_item_types
  50:     0x7f22aa5f6e11 - rustc_query_system[284fc37ba8dbaa13]::query::plumbing::try_execute_query::<rustc_query_impl[14a35b422f4e9e94]::queries::check_mod_item_types, rustc_query_impl[14a35b422f4e9e94]::plumbing::QueryCtxt>
  51:     0x7f22aa5f6a51 - rustc_query_impl[14a35b422f4e9e94]::get_query::check_mod_item_types
  52:     0x7f22aa41a524 - <rustc_middle[f12e14326fcb6d37]::hir::map::Map>::for_each_module::<rustc_hir_analysis[df7ae5e86821b533]::check_crate::{closure#6}::{closure#0}>
  53:     0x7f22aa41715b - rustc_hir_analysis[df7ae5e86821b533]::check_crate
  54:     0x7f22aa40a025 - rustc_interface[5dd728079daf5b2f]::passes::analysis
  55:     0x7f22aa710227 - rustc_query_system[284fc37ba8dbaa13]::query::plumbing::try_execute_query::<rustc_query_impl[14a35b422f4e9e94]::queries::analysis, rustc_query_impl[14a35b422f4e9e94]::plumbing::QueryCtxt>
  56:     0x7f22aa70ff43 - rustc_query_impl[14a35b422f4e9e94]::get_query::analysis
  57:     0x7f22aa1b79bf - <rustc_middle[f12e14326fcb6d37]::ty::context::GlobalCtxt>::enter::<rustc_driver_impl[dde0876b390e6a89]::run_compiler::{closure#1}::{closure#2}::{closure#4}, core[1a45016e46435943]::result::Result<(), rustc_span[3e163d59592952e6]::ErrorGuaranteed>>
  58:     0x7f22aa1b6acf - <rustc_interface[5dd728079daf5b2f]::interface::Compiler>::enter::<rustc_driver_impl[dde0876b390e6a89]::run_compiler::{closure#1}::{closure#2}, core[1a45016e46435943]::result::Result<core[1a45016e46435943]::option::Option<rustc_interface[5dd728079daf5b2f]::queries::Linker>, rustc_span[3e163d59592952e6]::ErrorGuaranteed>>
  59:     0x7f22aa1b4b71 - rustc_span[3e163d59592952e6]::set_source_map::<core[1a45016e46435943]::result::Result<(), rustc_span[3e163d59592952e6]::ErrorGuaranteed>, rustc_interface[5dd728079daf5b2f]::interface::run_compiler<core[1a45016e46435943]::result::Result<(), rustc_span[3e163d59592952e6]::ErrorGuaranteed>, rustc_driver_impl[dde0876b390e6a89]::run_compiler::{closure#1}>::{closure#0}::{closure#0}>
  60:     0x7f22aa1b4220 - std[d48aaa48ad184f7f]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[5dd728079daf5b2f]::util::run_in_thread_pool_with_globals<rustc_interface[5dd728079daf5b2f]::interface::run_compiler<core[1a45016e46435943]::result::Result<(), rustc_span[3e163d59592952e6]::ErrorGuaranteed>, rustc_driver_impl[dde0876b390e6a89]::run_compiler::{closure#1}>::{closure#0}, core[1a45016e46435943]::result::Result<(), rustc_span[3e163d59592952e6]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[1a45016e46435943]::result::Result<(), rustc_span[3e163d59592952e6]::ErrorGuaranteed>>
  61:     0x7f22aa872eb5 - <<std[d48aaa48ad184f7f]::thread::Builder>::spawn_unchecked_<rustc_interface[5dd728079daf5b2f]::util::run_in_thread_pool_with_globals<rustc_interface[5dd728079daf5b2f]::interface::run_compiler<core[1a45016e46435943]::result::Result<(), rustc_span[3e163d59592952e6]::ErrorGuaranteed>, rustc_driver_impl[dde0876b390e6a89]::run_compiler::{closure#1}>::{closure#0}, core[1a45016e46435943]::result::Result<(), rustc_span[3e163d59592952e6]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[1a45016e46435943]::result::Result<(), rustc_span[3e163d59592952e6]::ErrorGuaranteed>>::{closure#1} as core[1a45016e46435943]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  62:     0x7f22a7d774d5 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::hf9d590878bec4a84
                               at /rustc/c4190f2d3a46a59f435f7b42f58bc22b2f4d6917/library/alloc/src/boxed.rs:1985:9
  63:     0x7f22a7d774d5 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h3b901df10d727b47
                               at /rustc/c4190f2d3a46a59f435f7b42f58bc22b2f4d6917/library/alloc/src/boxed.rs:1985:9
  64:     0x7f22a7d774d5 - std::sys::unix::thread::Thread::new::thread_start::hbbc99806fcfda4ba
                               at /rustc/c4190f2d3a46a59f435f7b42f58bc22b2f4d6917/library/std/src/sys/unix/thread.rs:108:17
  65:     0x7f22a7b13bb5 - <unknown>
  66:     0x7f22a7b95d90 - <unknown>
  67:                0x0 - <unknown>

note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md

note: rustc 1.71.0-nightly (c4190f2d3 2023-05-07) running on x86_64-unknown-linux-gnu

note: compiler flags: -Z drop-tracking-mir=yes

query stack during panic:
#0 [mir_borrowck] borrow-checking `call_connect`
#1 [type_of] computing type of `call_connect::{opaque#0}`
#2 [check_mod_item_types] checking item types in top-level module
#3 [analysis] running analysis passes on this crateerror: internal compiler error: compiler/rustc_trait_selection/src/traits/select/mod.rs:3019:26: unexpected region: ReError

thread 'rustc' panicked at 'Box<dyn Any>', /rustc/c4190f2d3a46a59f435f7b42f58bc22b2f4d6917/compiler/rustc_errors/src/lib.rs:1650:9
stack backtrace:
   0:     0x7f22a7d69e71 - std::backtrace_rs::backtrace::libunwind::trace::hdca2f1d760ae3bfc
                               at /rustc/c4190f2d3a46a59f435f7b42f58bc22b2f4d6917/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5
   1:     0x7f22a7d69e71 - std::backtrace_rs::backtrace::trace_unsynchronized::hd02181015534cc1c
                               at /rustc/c4190f2d3a46a59f435f7b42f58bc22b2f4d6917/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7f22a7d69e71 - std::sys_common::backtrace::_print_fmt::h027d0dd83d9c6057
                               at /rustc/c4190f2d3a46a59f435f7b42f58bc22b2f4d6917/library/std/src/sys_common/backtrace.rs:65:5
   3:     0x7f22a7d69e71 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hc3454f8104aa16e4
                               at /rustc/c4190f2d3a46a59f435f7b42f58bc22b2f4d6917/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x7f22a7dca1bf - core::fmt::rt::Argument::fmt::haca00ab3f8062a1f
                               at /rustc/c4190f2d3a46a59f435f7b42f58bc22b2f4d6917/library/core/src/fmt/rt.rs:138:9
   5:     0x7f22a7dca1bf - core::fmt::write::he3e34afeea0f8a6d
                               at /rustc/c4190f2d3a46a59f435f7b42f58bc22b2f4d6917/library/core/src/fmt/mod.rs:1094:21
   6:     0x7f22a7d5d141 - std::io::Write::write_fmt::h0dda8fe866ff6ad9
                               at /rustc/c4190f2d3a46a59f435f7b42f58bc22b2f4d6917/library/std/src/io/mod.rs:1712:15
   7:     0x7f22a7d69c85 - std::sys_common::backtrace::_print::hdee7445a3e0bc35e
                               at /rustc/c4190f2d3a46a59f435f7b42f58bc22b2f4d6917/library/std/src/sys_common/backtrace.rs:47:5
   8:     0x7f22a7d69c85 - std::sys_common::backtrace::print::h88d45cc795ad4f3a
                               at /rustc/c4190f2d3a46a59f435f7b42f58bc22b2f4d6917/library/std/src/sys_common/backtrace.rs:34:9
   9:     0x7f22a7d6c917 - std::panicking::default_hook::{{closure}}::h0c28f70af069bb4e
  10:     0x7f22a7d6c704 - std::panicking::default_hook::h9d9751edb4b25952
                               at /rustc/c4190f2d3a46a59f435f7b42f58bc22b2f4d6917/library/std/src/panicking.rs:288:9
  11:     0x7f22aaf89e4b - rustc_driver_impl[dde0876b390e6a89]::install_ice_hook::{closure#0}
  12:     0x7f22a7d6d037 - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::hd829a428c0494b99
                               at /rustc/c4190f2d3a46a59f435f7b42f58bc22b2f4d6917/library/alloc/src/boxed.rs:1999:9
  13:     0x7f22a7d6d037 - std::panicking::rust_panic_with_hook::hb6e77b312dba3d0e
                               at /rustc/c4190f2d3a46a59f435f7b42f58bc22b2f4d6917/library/std/src/panicking.rs:695:13
  14:     0x7f22ab44e221 - std[d48aaa48ad184f7f]::panicking::begin_panic::<rustc_errors[f0db23b40a7f92ee]::ExplicitBug>::{closure#0}
  15:     0x7f22ab44de16 - std[d48aaa48ad184f7f]::sys_common::backtrace::__rust_end_short_backtrace::<std[d48aaa48ad184f7f]::panicking::begin_panic<rustc_errors[f0db23b40a7f92ee]::ExplicitBug>::{closure#0}, !>
  16:     0x7f22ab477ac6 - std[d48aaa48ad184f7f]::panicking::begin_panic::<rustc_errors[f0db23b40a7f92ee]::ExplicitBug>
  17:     0x7f22ab471ec4 - <rustc_errors[f0db23b40a7f92ee]::HandlerInner>::bug::<alloc[f90fa24b258e2697]::string::String>
  18:     0x7f22ab471bf6 - <rustc_errors[f0db23b40a7f92ee]::Handler>::bug::<alloc[f90fa24b258e2697]::string::String>
  19:     0x7f22ab4f9aac - rustc_middle[f12e14326fcb6d37]::util::bug::opt_span_bug_fmt::<rustc_span[3e163d59592952e6]::span_encoding::Span>::{closure#0}
  20:     0x7f22ab4f92da - rustc_middle[f12e14326fcb6d37]::ty::context::tls::with_opt::<rustc_middle[f12e14326fcb6d37]::util::bug::opt_span_bug_fmt<rustc_span[3e163d59592952e6]::span_encoding::Span>::{closure#0}, !>::{closure#0}
  21:     0x7f22ab4f92aa - rustc_middle[f12e14326fcb6d37]::ty::context::tls::with_context_opt::<rustc_middle[f12e14326fcb6d37]::ty::context::tls::with_opt<rustc_middle[f12e14326fcb6d37]::util::bug::opt_span_bug_fmt<rustc_span[3e163d59592952e6]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
  22:     0x7f22a919becd - rustc_middle[f12e14326fcb6d37]::util::bug::bug_fmt
  23:     0x7f22abbab674 - rustc_trait_selection[f271c5c5f9af5999]::traits::select::bind_generator_hidden_types_above::{closure#0}::{closure#1}::{closure#0}
  24:     0x7f22abb4fea2 - <rustc_middle[f12e14326fcb6d37]::ty::subst::GenericArg as rustc_type_ir[79abdb9a60271110]::fold::TypeFoldable<rustc_middle[f12e14326fcb6d37]::ty::context::TyCtxt>>::try_fold_with::<rustc_middle[f12e14326fcb6d37]::ty::fold::RegionFolder>
  25:     0x7f22abb04c0f - <&rustc_middle[f12e14326fcb6d37]::ty::list::List<rustc_middle[f12e14326fcb6d37]::ty::subst::GenericArg> as rustc_type_ir[79abdb9a60271110]::fold::TypeFoldable<rustc_middle[f12e14326fcb6d37]::ty::context::TyCtxt>>::try_fold_with::<rustc_middle[f12e14326fcb6d37]::ty::fold::RegionFolder>
  26:     0x7f22ababc596 - <rustc_middle[f12e14326fcb6d37]::ty::sty::AliasTy as rustc_type_ir[79abdb9a60271110]::fold::TypeFoldable<rustc_middle[f12e14326fcb6d37]::ty::context::TyCtxt>>::try_fold_with::<rustc_middle[f12e14326fcb6d37]::ty::fold::RegionFolder>
  27:     0x7f22abb3731a - <rustc_middle[f12e14326fcb6d37]::ty::Ty as rustc_type_ir[79abdb9a60271110]::fold::TypeSuperFoldable<rustc_middle[f12e14326fcb6d37]::ty::context::TyCtxt>>::super_fold_with::<rustc_middle[f12e14326fcb6d37]::ty::fold::RegionFolder>
  28:     0x7f22abba6f39 - <rustc_middle[f12e14326fcb6d37]::ty::context::TyCtxt>::fold_regions::<rustc_middle[f12e14326fcb6d37]::ty::Ty, rustc_trait_selection[f271c5c5f9af5999]::traits::select::bind_generator_hidden_types_above::{closure#0}::{closure#1}::{closure#0}>
  29:     0x7f22abba0e28 - <&mut rustc_trait_selection[f271c5c5f9af5999]::traits::select::bind_generator_hidden_types_above::{closure#0}::{closure#1} as core[1a45016e46435943]::ops::function::FnOnce<(rustc_middle[f12e14326fcb6d37]::ty::subst::EarlyBinder<rustc_middle[f12e14326fcb6d37]::ty::Ty>,)>>::call_once
  30:     0x7f22abafab3a - <alloc[f90fa24b258e2697]::vec::Vec<rustc_middle[f12e14326fcb6d37]::ty::Ty> as alloc[f90fa24b258e2697]::vec::spec_from_iter::SpecFromIter<rustc_middle[f12e14326fcb6d37]::ty::Ty, core[1a45016e46435943]::iter::adapters::map::Map<core[1a45016e46435943]::iter::adapters::filter::Filter<core[1a45016e46435943]::iter::adapters::map::Map<core[1a45016e46435943]::iter::adapters::filter::Filter<core[1a45016e46435943]::slice::iter::Iter<rustc_middle[f12e14326fcb6d37]::mir::query::GeneratorSavedTy>, <rustc_middle[f12e14326fcb6d37]::ty::context::TyCtxt>::generator_hidden_types::{closure#0}>, <rustc_middle[f12e14326fcb6d37]::ty::context::TyCtxt>::generator_hidden_types::{closure#1}>, rustc_trait_selection[f271c5c5f9af5999]::traits::select::bind_generator_hidden_types_above::{closure#0}::{closure#0}>, rustc_trait_selection[f271c5c5f9af5999]::traits::select::bind_generator_hidden_types_above::{closure#0}::{closure#1}>>>::from_iter
  31:     0x7f22abba3a44 - rustc_trait_selection[f271c5c5f9af5999]::traits::select::bind_generator_hidden_types_above
  32:     0x7f22a9198130 - <rustc_trait_selection[f271c5c5f9af5999]::traits::select::SelectionContext>::select
  33:     0x7f22a916aeb7 - <rustc_trait_selection[f271c5c5f9af5999]::traits::fulfill::FulfillProcessor as rustc_data_structures[e6a995bd1645ab1f]::obligation_forest::ObligationProcessor>::process_obligation
  34:     0x7f22a9168561 - <rustc_data_structures[e6a995bd1645ab1f]::obligation_forest::ObligationForest<rustc_trait_selection[f271c5c5f9af5999]::traits::fulfill::PendingPredicateObligation>>::process_obligations::<rustc_trait_selection[f271c5c5f9af5999]::traits::fulfill::FulfillProcessor>
  35:     0x7f22a931ceb2 - <rustc_trait_selection[f271c5c5f9af5999]::traits::engine::ObligationCtxt>::select_all_or_error
  36:     0x7f22a997e3f2 - rustc_trait_selection[f271c5c5f9af5999]::traits::query::type_op::custom::scrape_region_constraints::<rustc_borrowck[fe7f2bcff357714e]::type_check::InstantiateOpaqueType, (), <rustc_borrowck[fe7f2bcff357714e]::type_check::InstantiateOpaqueType as rustc_trait_selection[f271c5c5f9af5999]::traits::query::type_op::TypeOp>::fully_perform::{closure#0}>
  37:     0x7f22a997dac0 - <rustc_borrowck[fe7f2bcff357714e]::type_check::TypeChecker>::fully_perform_op::<(), rustc_borrowck[fe7f2bcff357714e]::type_check::InstantiateOpaqueType>
  38:     0x7f22a997c5fa - <rustc_infer[81cc4442e2774718]::infer::nll_relate::TypeRelating<rustc_borrowck[fe7f2bcff357714e]::type_check::relate_tys::NllTypeRelatingDelegate>>::relate_opaques
  39:     0x7f22a9955077 - <rustc_borrowck[fe7f2bcff357714e]::type_check::TypeChecker>::typeck_mir
  40:     0x7f22a98d3397 - rustc_borrowck[fe7f2bcff357714e]::nll::compute_regions
  41:     0x7f22a9880bec - rustc_borrowck[fe7f2bcff357714e]::do_mir_borrowck
  42:     0x7f22a987d36b - rustc_borrowck[fe7f2bcff357714e]::mir_borrowck
  43:     0x7f22a987b708 - rustc_query_system[284fc37ba8dbaa13]::query::plumbing::try_execute_query::<rustc_query_impl[14a35b422f4e9e94]::queries::mir_borrowck, rustc_query_impl[14a35b422f4e9e94]::plumbing::QueryCtxt>
  44:     0x7f22a987b3f0 - rustc_query_impl[14a35b422f4e9e94]::get_query::mir_borrowck
  45:     0x7f22aa340d7d - rustc_hir_analysis[df7ae5e86821b533]::collect::type_of::type_of
  46:     0x7f22a962641b - rustc_query_system[284fc37ba8dbaa13]::query::plumbing::try_execute_query::<rustc_query_impl[14a35b422f4e9e94]::queries::type_of, rustc_query_impl[14a35b422f4e9e94]::plumbing::QueryCtxt>
  47:     0x7f22a9625760 - rustc_query_impl[14a35b422f4e9e94]::get_query::type_of
  48:     0x7f22a9fb25e0 - rustc_middle[f12e14326fcb6d37]::ty::query::query_get_at::<rustc_query_system[284fc37ba8dbaa13]::query::caches::DefaultCache<rustc_span[3e163d59592952e6]::def_id::DefId, rustc_middle[f12e14326fcb6d37]::query::erase::Erased<[u8; 8usize]>>>
  49:     0x7f22a9faca09 - rustc_hir_analysis[df7ae5e86821b533]::check::check::check_mod_item_types
  50:     0x7f22aa5f6e11 - rustc_query_system[284fc37ba8dbaa13]::query::plumbing::try_execute_query::<rustc_query_impl[14a35b422f4e9e94]::queries::check_mod_item_types, rustc_query_impl[14a35b422f4e9e94]::plumbing::QueryCtxt>
  51:     0x7f22aa5f6a51 - rustc_query_impl[14a35b422f4e9e94]::get_query::check_mod_item_types
  52:     0x7f22aa41a524 - <rustc_middle[f12e14326fcb6d37]::hir::map::Map>::for_each_module::<rustc_hir_analysis[df7ae5e86821b533]::check_crate::{closure#6}::{closure#0}>
  53:     0x7f22aa41715b - rustc_hir_analysis[df7ae5e86821b533]::check_crate
  54:     0x7f22aa40a025 - rustc_interface[5dd728079daf5b2f]::passes::analysis
  55:     0x7f22aa710227 - rustc_query_system[284fc37ba8dbaa13]::query::plumbing::try_execute_query::<rustc_query_impl[14a35b422f4e9e94]::queries::analysis, rustc_query_impl[14a35b422f4e9e94]::plumbing::QueryCtxt>
  56:     0x7f22aa70ff43 - rustc_query_impl[14a35b422f4e9e94]::get_query::analysis
  57:     0x7f22aa1b79bf - <rustc_middle[f12e14326fcb6d37]::ty::context::GlobalCtxt>::enter::<rustc_driver_impl[dde0876b390e6a89]::run_compiler::{closure#1}::{closure#2}::{closure#4}, core[1a45016e46435943]::result::Result<(), rustc_span[3e163d59592952e6]::ErrorGuaranteed>>
  58:     0x7f22aa1b6acf - <rustc_interface[5dd728079daf5b2f]::interface::Compiler>::enter::<rustc_driver_impl[dde0876b390e6a89]::run_compiler::{closure#1}::{closure#2}, core[1a45016e46435943]::result::Result<core[1a45016e46435943]::option::Option<rustc_interface[5dd728079daf5b2f]::queries::Linker>, rustc_span[3e163d59592952e6]::ErrorGuaranteed>>
  59:     0x7f22aa1b4b71 - rustc_span[3e163d59592952e6]::set_source_map::<core[1a45016e46435943]::result::Result<(), rustc_span[3e163d59592952e6]::ErrorGuaranteed>, rustc_interface[5dd728079daf5b2f]::interface::run_compiler<core[1a45016e46435943]::result::Result<(), rustc_span[3e163d59592952e6]::ErrorGuaranteed>, rustc_driver_impl[dde0876b390e6a89]::run_compiler::{closure#1}>::{closure#0}::{closure#0}>
  60:     0x7f22aa1b4220 - std[d48aaa48ad184f7f]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[5dd728079daf5b2f]::util::run_in_thread_pool_with_globals<rustc_interface[5dd728079daf5b2f]::interface::run_compiler<core[1a45016e46435943]::result::Result<(), rustc_span[3e163d59592952e6]::ErrorGuaranteed>, rustc_driver_impl[dde0876b390e6a89]::run_compiler::{closure#1}>::{closure#0}, core[1a45016e46435943]::result::Result<(), rustc_span[3e163d59592952e6]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[1a45016e46435943]::result::Result<(), rustc_span[3e163d59592952e6]::ErrorGuaranteed>>
  61:     0x7f22aa872eb5 - <<std[d48aaa48ad184f7f]::thread::Builder>::spawn_unchecked_<rustc_interface[5dd728079daf5b2f]::util::run_in_thread_pool_with_globals<rustc_interface[5dd728079daf5b2f]::interface::run_compiler<core[1a45016e46435943]::result::Result<(), rustc_span[3e163d59592952e6]::ErrorGuaranteed>, rustc_driver_impl[dde0876b390e6a89]::run_compiler::{closure#1}>::{closure#0}, core[1a45016e46435943]::result::Result<(), rustc_span[3e163d59592952e6]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[1a45016e46435943]::result::Result<(), rustc_span[3e163d59592952e6]::ErrorGuaranteed>>::{closure#1} as core[1a45016e46435943]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  62:     0x7f22a7d774d5 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::hf9d590878bec4a84
                               at /rustc/c4190f2d3a46a59f435f7b42f58bc22b2f4d6917/library/alloc/src/boxed.rs:1985:9
  63:     0x7f22a7d774d5 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h3b901df10d727b47
                               at /rustc/c4190f2d3a46a59f435f7b42f58bc22b2f4d6917/library/alloc/src/boxed.rs:1985:9
  64:     0x7f22a7d774d5 - std::sys::unix::thread::Thread::new::thread_start::hbbc99806fcfda4ba
                               at /rustc/c4190f2d3a46a59f435f7b42f58bc22b2f4d6917/library/std/src/sys/unix/thread.rs:108:17
  65:     0x7f22a7b13bb5 - <unknown>
  66:     0x7f22a7b95d90 - <unknown>
  67:                0x0 - <unknown>

note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md

note: rustc 1.71.0-nightly (c4190f2d3 2023-05-07) running on x86_64-unknown-linux-gnu

note: compiler flags: -Z drop-tracking-mir=yes

query stack during panic:
#0 [mir_borrowck] borrow-checking `call_connect`
#1 [type_of] computing type of `call_connect::{opaque#0}`
#2 [check_mod_item_types] checking item types in top-level module
#3 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to 2 previous errors; 1 warning emitted

For more information about this error, try `rustc --explain E0261`.
end of query stack
error: aborting due to 2 previous errors; 1 warning emitted

For more information about this error, try `rustc --explain E0261`.

[matthiaskrgr]

Another regression of #110835 cc @nnethercote

[nnethercote]

Before I create a fix: @compiler-errors, is ReError an expected/reasonable value in this match? I.e. is the right fix here just to allow ReError?

[compiler-errors]

@nnethercote I don't think so. Actually just looked, think it's because we're not erasing ReError properly. Let me put up a quick fix.