[ICE]: cannot convert `'a/#3` to a region vid

[wxie7]

Code

struct Foo;
impl Foo {
    #[allow(dead_code)]
    fn foo(self) {
        panic!("wrong method!")
    }
}
trait Trait {
    fn foo(self);
}
impl<'a, 'b, 'c> Trait for &'a &'b &'c Foo {
    async fn pass2<'a, 'b, 'c>(self) {}
}
fn main() {
    let x = &(&(&Foo));
    x.foo();
}

Meta

rustc --version --verbose:

rustc 1.84.0-nightly (b91a3a056 2024-11-07)
binary: rustc
commit-hash: b91a3a05609a46f73d23e0995ae7ebb4a4f429a5
commit-date: 2024-11-07
host: x86_64-unknown-linux-gnu
release: 1.84.0-nightly
LLVM version: 19.1.3

Error output

error[E0670]: `async fn` is not permitted in Rust 2015
  --> mutant.rs:12:5
   |
12 |     async fn pass2<'a, 'b, 'c>(self) {}
   |     ^^^^^ to use `async fn`, switch to Rust 2018 or later
   |
   = help: pass `--edition 2021` to `rustc`
   = note: for more on editions, read https://doc.rust-lang.org/edition-guide

error[E0496]: lifetime name `'a` shadows a lifetime name that is already in scope
  --> mutant.rs:12:20
   |
11 | impl<'a, 'b, 'c> Trait for &'a &'b &'c Foo {
   |      -- first declared here
12 |     async fn pass2<'a, 'b, 'c>(self) {}
   |                    ^^ lifetime `'a` already in scope

error[E0496]: lifetime name `'b` shadows a lifetime name that is already in scope
  --> mutant.rs:12:24
   |
11 | impl<'a, 'b, 'c> Trait for &'a &'b &'c Foo {
   |          -- first declared here
12 |     async fn pass2<'a, 'b, 'c>(self) {}
   |                        ^^ lifetime `'b` already in scope

error[E0496]: lifetime name `'c` shadows a lifetime name that is already in scope
  --> mutant.rs:12:28
   |
11 | impl<'a, 'b, 'c> Trait for &'a &'b &'c Foo {
   |              -- first declared here
12 |     async fn pass2<'a, 'b, 'c>(self) {}
   |                            ^^ lifetime `'c` already in scope

error[E0407]: method `pass2` is not a member of trait `Trait`
  --> mutant.rs:12:5
   |
12 |     async fn pass2<'a, 'b, 'c>(self) {}
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not a member of trait `Trait`

error[E0046]: not all trait items implemented, missing: `foo`
  --> mutant.rs:11:1
   |
9  |     fn foo(self);
   |     ------------- `foo` from trait
10 | }
11 | impl<'a, 'b, 'c> Trait for &'a &'b &'c Foo {
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ missing `foo` in implementation

error: internal compiler error: compiler/rustc_borrowck/src/universal_regions.rs:904:36: cannot convert `'a/#3` to a region vid

thread 'rustc' panicked at compiler/rustc_borrowck/src/universal_regions.rs:904:36:
Box<dyn Any>
stack backtrace:
   0:     0x7faaf585517a - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::hfadad24fb33e3d1a
   1:     0x7faaf60040a6 - core::fmt::write::h42d25fbda60cd99f
   2:     0x7faaf73c3351 - std::io::Write::write_fmt::hc2819193e80b365e
   3:     0x7faaf5854fd2 - std::sys::backtrace::BacktraceLock::print::h9450230402d77664
   4:     0x7faaf58574d6 - std::panicking::default_hook::{{closure}}::h739047d4d787c596
   5:     0x7faaf5857320 - std::panicking::default_hook::h203d1229480f37a5
   6:     0x7faaf48d2269 - std[56fe22ad9ea837fd]::panicking::update_hook::<alloc[b5641001d343df5f]::boxed::Box<rustc_driver_impl[945e9afaf49c7d35]::install_ice_hook::{closure#0}>>::{closure#0}
   7:     0x7faaf5857be8 - std::panicking::rust_panic_with_hook::h657fdcc17f7e2546
   8:     0x7faaf490c191 - std[56fe22ad9ea837fd]::panicking::begin_panic::<rustc_errors[43c84716ac990581]::ExplicitBug>::{closure#0}
   9:     0x7faaf48ff166 - std[56fe22ad9ea837fd]::sys::backtrace::__rust_end_short_backtrace::<std[56fe22ad9ea837fd]::panicking::begin_panic<rustc_errors[43c84716ac990581]::ExplicitBug>::{closure#0}, !>
  10:     0x7faaf48feefe - std[56fe22ad9ea837fd]::panicking::begin_panic::<rustc_errors[43c84716ac990581]::ExplicitBug>
  11:     0x7faaf4915e71 - <rustc_errors[43c84716ac990581]::diagnostic::BugAbort as rustc_errors[43c84716ac990581]::diagnostic::EmissionGuarantee>::emit_producing_guarantee
  12:     0x7faaf4f8f2c3 - rustc_middle[f0eb6ba890d0a9bb]::util::bug::opt_span_bug_fmt::<rustc_span[db86d96c2ae2e3a4]::span_encoding::Span>::{closure#0}
  13:     0x7faaf4f758ba - rustc_middle[f0eb6ba890d0a9bb]::ty::context::tls::with_opt::<rustc_middle[f0eb6ba890d0a9bb]::util::bug::opt_span_bug_fmt<rustc_span[db86d96c2ae2e3a4]::span_encoding::Span>::{closure#0}, !>::{closure#0}
  14:     0x7faaf4f7574b - rustc_middle[f0eb6ba890d0a9bb]::ty::context::tls::with_context_opt::<rustc_middle[f0eb6ba890d0a9bb]::ty::context::tls::with_opt<rustc_middle[f0eb6ba890d0a9bb]::util::bug::opt_span_bug_fmt<rustc_span[db86d96c2ae2e3a4]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
  15:     0x7faaf31e7300 - rustc_middle[f0eb6ba890d0a9bb]::util::bug::bug_fmt
  16:     0x7faaf75c2ce0 - <rustc_borrowck[de200e79d11a1023]::universal_regions::UniversalRegionIndices>::to_region_vid.cold
  17:     0x7faaf6055b14 - <rustc_borrowck[de200e79d11a1023]::universal_regions::UniversalRegionIndices>::fold_to_region_vids::<rustc_type_ir[8408d34320f8a6fb]::binder::Binder<rustc_middle[f0eb6ba890d0a9bb]::ty::context::TyCtxt, rustc_type_ir[8408d34320f8a6fb]::ty_kind::FnSig<rustc_middle[f0eb6ba890d0a9bb]::ty::context::TyCtxt>>>::{closure#0}
  18:     0x7faaf6051924 - <&rustc_middle[f0eb6ba890d0a9bb]::ty::list::RawList<(), rustc_middle[f0eb6ba890d0a9bb]::ty::generic_args::GenericArg> as rustc_type_ir[8408d34320f8a6fb]::fold::TypeFoldable<rustc_middle[f0eb6ba890d0a9bb]::ty::context::TyCtxt>>::try_fold_with::<rustc_middle[f0eb6ba890d0a9bb]::ty::fold::RegionFolder>
  19:     0x7faaf60527e4 - <rustc_middle[f0eb6ba890d0a9bb]::ty::Ty as rustc_type_ir[8408d34320f8a6fb]::fold::TypeSuperFoldable<rustc_middle[f0eb6ba890d0a9bb]::ty::context::TyCtxt>>::try_super_fold_with::<rustc_middle[f0eb6ba890d0a9bb]::ty::fold::RegionFolder>
  20:     0x7faaf6051da7 - <&rustc_middle[f0eb6ba890d0a9bb]::ty::list::RawList<(), rustc_middle[f0eb6ba890d0a9bb]::ty::Ty> as rustc_type_ir[8408d34320f8a6fb]::fold::TypeFoldable<rustc_middle[f0eb6ba890d0a9bb]::ty::context::TyCtxt>>::try_fold_with::<rustc_middle[f0eb6ba890d0a9bb]::ty::fold::RegionFolder>
  21:     0x7faaf70b3648 - rustc_borrowck[de200e79d11a1023]::do_mir_borrowck
  22:     0x7faaf70b228a - rustc_query_impl[1357963d8dd30e8b]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[1357963d8dd30e8b]::query_impl::mir_borrowck::dynamic_query::{closure#2}::{closure#0}, rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 8usize]>>
  23:     0x7faaf6723681 - rustc_query_system[887bb79932b1d8c1]::query::plumbing::try_execute_query::<rustc_query_impl[1357963d8dd30e8b]::DynamicConfig<rustc_query_system[887bb79932b1d8c1]::query::caches::VecCache<rustc_span[db86d96c2ae2e3a4]::def_id::LocalDefId, rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[1357963d8dd30e8b]::plumbing::QueryCtxt, false>
  24:     0x7faaf672318d - rustc_query_impl[1357963d8dd30e8b]::query_impl::mir_borrowck::get_query_non_incr::__rust_end_short_backtrace
  25:     0x7faaf69cc8f3 - rustc_middle[f0eb6ba890d0a9bb]::query::plumbing::query_get_at::<rustc_query_system[887bb79932b1d8c1]::query::caches::VecCache<rustc_span[db86d96c2ae2e3a4]::def_id::LocalDefId, rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 8usize]>>>
  26:     0x7faaf713b05e - rustc_hir_analysis[af6e6fecb0b5810e]::collect::type_of::type_of_opaque
  27:     0x7faaf713aed1 - rustc_query_impl[1357963d8dd30e8b]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[1357963d8dd30e8b]::query_impl::type_of_opaque::dynamic_query::{closure#2}::{closure#0}, rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 8usize]>>
  28:     0x7faaf6023bb6 - rustc_query_system[887bb79932b1d8c1]::query::plumbing::try_execute_query::<rustc_query_impl[1357963d8dd30e8b]::DynamicConfig<rustc_query_system[887bb79932b1d8c1]::query::caches::DefIdCache<rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[1357963d8dd30e8b]::plumbing::QueryCtxt, false>
  29:     0x7faaf72137f5 - rustc_query_impl[1357963d8dd30e8b]::query_impl::type_of_opaque::get_query_non_incr::__rust_end_short_backtrace
  30:     0x7faaf64f6540 - rustc_middle[f0eb6ba890d0a9bb]::query::plumbing::query_get_at::<rustc_query_system[887bb79932b1d8c1]::query::caches::DefIdCache<rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 8usize]>>>
  31:     0x7faaf318f449 - rustc_hir_analysis[af6e6fecb0b5810e]::collect::type_of::type_of
  32:     0x7faaf6024ef2 - rustc_query_impl[1357963d8dd30e8b]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[1357963d8dd30e8b]::query_impl::type_of::dynamic_query::{closure#2}::{closure#0}, rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 8usize]>>
  33:     0x7faaf6023bb6 - rustc_query_system[887bb79932b1d8c1]::query::plumbing::try_execute_query::<rustc_query_impl[1357963d8dd30e8b]::DynamicConfig<rustc_query_system[887bb79932b1d8c1]::query::caches::DefIdCache<rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[1357963d8dd30e8b]::plumbing::QueryCtxt, false>
  34:     0x7faaf6023767 - rustc_query_impl[1357963d8dd30e8b]::query_impl::type_of::get_query_non_incr::__rust_end_short_backtrace
  35:     0x7faaf64f6540 - rustc_middle[f0eb6ba890d0a9bb]::query::plumbing::query_get_at::<rustc_query_system[887bb79932b1d8c1]::query::caches::DefIdCache<rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 8usize]>>>
  36:     0x7faaf7149109 - rustc_hir_analysis[af6e6fecb0b5810e]::check::check::check_item_type
  37:     0x7faaf3885a93 - rustc_hir_analysis[af6e6fecb0b5810e]::check::wfcheck::check_well_formed
  38:     0x7faaf63ef1c7 - rustc_query_impl[1357963d8dd30e8b]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[1357963d8dd30e8b]::query_impl::check_well_formed::dynamic_query::{closure#2}::{closure#0}, rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 1usize]>>
  39:     0x7faaf63ee919 - rustc_query_system[887bb79932b1d8c1]::query::plumbing::try_execute_query::<rustc_query_impl[1357963d8dd30e8b]::DynamicConfig<rustc_query_system[887bb79932b1d8c1]::query::caches::VecCache<rustc_span[db86d96c2ae2e3a4]::def_id::LocalDefId, rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[1357963d8dd30e8b]::plumbing::QueryCtxt, false>
  40:     0x7faaf63ee590 - rustc_query_impl[1357963d8dd30e8b]::query_impl::check_well_formed::get_query_non_incr::__rust_end_short_backtrace
  41:     0x7faaf63ef247 - rustc_middle[f0eb6ba890d0a9bb]::query::plumbing::query_ensure_error_guaranteed::<rustc_query_system[887bb79932b1d8c1]::query::caches::VecCache<rustc_span[db86d96c2ae2e3a4]::def_id::LocalDefId, rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 1usize]>>, ()>
  42:     0x7faaf63ef7f2 - rustc_hir_analysis[af6e6fecb0b5810e]::check::wfcheck::check_mod_type_wf
  43:     0x7faaf63ef26f - rustc_query_impl[1357963d8dd30e8b]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[1357963d8dd30e8b]::query_impl::check_mod_type_wf::dynamic_query::{closure#2}::{closure#0}, rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 1usize]>>
  44:     0x7faaf6bed0c1 - rustc_query_system[887bb79932b1d8c1]::query::plumbing::try_execute_query::<rustc_query_impl[1357963d8dd30e8b]::DynamicConfig<rustc_query_system[887bb79932b1d8c1]::query::caches::DefaultCache<rustc_span[db86d96c2ae2e3a4]::def_id::LocalModDefId, rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[1357963d8dd30e8b]::plumbing::QueryCtxt, false>
  45:     0x7faaf6bece70 - rustc_query_impl[1357963d8dd30e8b]::query_impl::check_mod_type_wf::get_query_non_incr::__rust_end_short_backtrace
  46:     0x7faaf671f42f - rustc_hir_analysis[af6e6fecb0b5810e]::check_crate
  47:     0x7faaf6868aca - rustc_interface[5fea8bf9cd0b71b5]::passes::run_required_analyses
  48:     0x7faaf6e0861e - rustc_interface[5fea8bf9cd0b71b5]::passes::analysis
  49:     0x7faaf6e085ef - rustc_query_impl[1357963d8dd30e8b]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[1357963d8dd30e8b]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 1usize]>>
  50:     0x7faaf6f92cee - rustc_query_system[887bb79932b1d8c1]::query::plumbing::try_execute_query::<rustc_query_impl[1357963d8dd30e8b]::DynamicConfig<rustc_query_system[887bb79932b1d8c1]::query::caches::SingleCache<rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[1357963d8dd30e8b]::plumbing::QueryCtxt, false>
  51:     0x7faaf6f929ce - rustc_query_impl[1357963d8dd30e8b]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  52:     0x7faaf6e8707a - rustc_interface[5fea8bf9cd0b71b5]::interface::run_compiler::<core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>, rustc_driver_impl[945e9afaf49c7d35]::run_compiler::{closure#0}>::{closure#1}
  53:     0x7faaf6ecd5d0 - std[56fe22ad9ea837fd]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[5fea8bf9cd0b71b5]::util::run_in_thread_with_globals<rustc_interface[5fea8bf9cd0b71b5]::util::run_in_thread_pool_with_globals<rustc_interface[5fea8bf9cd0b71b5]::interface::run_compiler<core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>, rustc_driver_impl[945e9afaf49c7d35]::run_compiler::{closure#0}>::{closure#1}, core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>>::{closure#0}, core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>>
  54:     0x7faaf6ecd9eb - <<std[56fe22ad9ea837fd]::thread::Builder>::spawn_unchecked_<rustc_interface[5fea8bf9cd0b71b5]::util::run_in_thread_with_globals<rustc_interface[5fea8bf9cd0b71b5]::util::run_in_thread_pool_with_globals<rustc_interface[5fea8bf9cd0b71b5]::interface::run_compiler<core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>, rustc_driver_impl[945e9afaf49c7d35]::run_compiler::{closure#0}>::{closure#1}, core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>>::{closure#0}, core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>>::{closure#1} as core[5ba82ee3405aa490]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  55:     0x7faaf6ece4b9 - std::sys::pal::unix::thread::Thread::new::thread_start::hb3d6392adeea417c
  56:     0x7faaf106bac3 - start_thread
                               at ./nptl/pthread_create.c:442:8
  57:     0x7faaf10fd850 - __GI___clone3
                               at ./misc/../sysdeps/unix/sysv/linux/x86_64/clone3.S:81
  58:                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: please make sure that you have updated to the latest nightly

note: compiler flags: --crate-type staticlib -C link-dead-code -C debuginfo=2 -C opt-level=3 -Z mir-opt-level=3

query stack during panic:
#0 [mir_borrowck] borrow-checking `<impl at mutant.rs:11:1: 11:43>::pass2`
#1 [type_of_opaque] computing type of opaque `<impl at mutant.rs:11:1: 11:43>::pass2::{opaque#0}`
end of query stack
error: aborting due to 7 previous errors

Some errors have detailed explanations: E0046, E0407, E0496, E0670.
For more information about an error, try `rustc --explain E0046`.

Backtrace

stack backtrace:
   0:     0x7faaf585517a - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::hfadad24fb33e3d1a
   1:     0x7faaf60040a6 - core::fmt::write::h42d25fbda60cd99f
   2:     0x7faaf73c3351 - std::io::Write::write_fmt::hc2819193e80b365e
   3:     0x7faaf5854fd2 - std::sys::backtrace::BacktraceLock::print::h9450230402d77664
   4:     0x7faaf58574d6 - std::panicking::default_hook::{{closure}}::h739047d4d787c596
   5:     0x7faaf5857320 - std::panicking::default_hook::h203d1229480f37a5
   6:     0x7faaf48d2269 - std[56fe22ad9ea837fd]::panicking::update_hook::<alloc[b5641001d343df5f]::boxed::Box<rustc_driver_impl[945e9afaf49c7d35]::install_ice_hook::{closure#0}>>::{closure#0}
   7:     0x7faaf5857be8 - std::panicking::rust_panic_with_hook::h657fdcc17f7e2546
   8:     0x7faaf490c191 - std[56fe22ad9ea837fd]::panicking::begin_panic::<rustc_errors[43c84716ac990581]::ExplicitBug>::{closure#0}
   9:     0x7faaf48ff166 - std[56fe22ad9ea837fd]::sys::backtrace::__rust_end_short_backtrace::<std[56fe22ad9ea837fd]::panicking::begin_panic<rustc_errors[43c84716ac990581]::ExplicitBug>::{closure#0}, !>
  10:     0x7faaf48feefe - std[56fe22ad9ea837fd]::panicking::begin_panic::<rustc_errors[43c84716ac990581]::ExplicitBug>
  11:     0x7faaf4915e71 - <rustc_errors[43c84716ac990581]::diagnostic::BugAbort as rustc_errors[43c84716ac990581]::diagnostic::EmissionGuarantee>::emit_producing_guarantee
  12:     0x7faaf4f8f2c3 - rustc_middle[f0eb6ba890d0a9bb]::util::bug::opt_span_bug_fmt::<rustc_span[db86d96c2ae2e3a4]::span_encoding::Span>::{closure#0}
  13:     0x7faaf4f758ba - rustc_middle[f0eb6ba890d0a9bb]::ty::context::tls::with_opt::<rustc_middle[f0eb6ba890d0a9bb]::util::bug::opt_span_bug_fmt<rustc_span[db86d96c2ae2e3a4]::span_encoding::Span>::{closure#0}, !>::{closure#0}
  14:     0x7faaf4f7574b - rustc_middle[f0eb6ba890d0a9bb]::ty::context::tls::with_context_opt::<rustc_middle[f0eb6ba890d0a9bb]::ty::context::tls::with_opt<rustc_middle[f0eb6ba890d0a9bb]::util::bug::opt_span_bug_fmt<rustc_span[db86d96c2ae2e3a4]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
  15:     0x7faaf31e7300 - rustc_middle[f0eb6ba890d0a9bb]::util::bug::bug_fmt
  16:     0x7faaf75c2ce0 - <rustc_borrowck[de200e79d11a1023]::universal_regions::UniversalRegionIndices>::to_region_vid.cold
  17:     0x7faaf6055b14 - <rustc_borrowck[de200e79d11a1023]::universal_regions::UniversalRegionIndices>::fold_to_region_vids::<rustc_type_ir[8408d34320f8a6fb]::binder::Binder<rustc_middle[f0eb6ba890d0a9bb]::ty::context::TyCtxt, rustc_type_ir[8408d34320f8a6fb]::ty_kind::FnSig<rustc_middle[f0eb6ba890d0a9bb]::ty::context::TyCtxt>>>::{closure#0}
  18:     0x7faaf6051924 - <&rustc_middle[f0eb6ba890d0a9bb]::ty::list::RawList<(), rustc_middle[f0eb6ba890d0a9bb]::ty::generic_args::GenericArg> as rustc_type_ir[8408d34320f8a6fb]::fold::TypeFoldable<rustc_middle[f0eb6ba890d0a9bb]::ty::context::TyCtxt>>::try_fold_with::<rustc_middle[f0eb6ba890d0a9bb]::ty::fold::RegionFolder>
  19:     0x7faaf60527e4 - <rustc_middle[f0eb6ba890d0a9bb]::ty::Ty as rustc_type_ir[8408d34320f8a6fb]::fold::TypeSuperFoldable<rustc_middle[f0eb6ba890d0a9bb]::ty::context::TyCtxt>>::try_super_fold_with::<rustc_middle[f0eb6ba890d0a9bb]::ty::fold::RegionFolder>
  20:     0x7faaf6051da7 - <&rustc_middle[f0eb6ba890d0a9bb]::ty::list::RawList<(), rustc_middle[f0eb6ba890d0a9bb]::ty::Ty> as rustc_type_ir[8408d34320f8a6fb]::fold::TypeFoldable<rustc_middle[f0eb6ba890d0a9bb]::ty::context::TyCtxt>>::try_fold_with::<rustc_middle[f0eb6ba890d0a9bb]::ty::fold::RegionFolder>
  21:     0x7faaf70b3648 - rustc_borrowck[de200e79d11a1023]::do_mir_borrowck
  22:     0x7faaf70b228a - rustc_query_impl[1357963d8dd30e8b]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[1357963d8dd30e8b]::query_impl::mir_borrowck::dynamic_query::{closure#2}::{closure#0}, rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 8usize]>>
  23:     0x7faaf6723681 - rustc_query_system[887bb79932b1d8c1]::query::plumbing::try_execute_query::<rustc_query_impl[1357963d8dd30e8b]::DynamicConfig<rustc_query_system[887bb79932b1d8c1]::query::caches::VecCache<rustc_span[db86d96c2ae2e3a4]::def_id::LocalDefId, rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[1357963d8dd30e8b]::plumbing::QueryCtxt, false>
  24:     0x7faaf672318d - rustc_query_impl[1357963d8dd30e8b]::query_impl::mir_borrowck::get_query_non_incr::__rust_end_short_backtrace
  25:     0x7faaf69cc8f3 - rustc_middle[f0eb6ba890d0a9bb]::query::plumbing::query_get_at::<rustc_query_system[887bb79932b1d8c1]::query::caches::VecCache<rustc_span[db86d96c2ae2e3a4]::def_id::LocalDefId, rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 8usize]>>>
  26:     0x7faaf713b05e - rustc_hir_analysis[af6e6fecb0b5810e]::collect::type_of::type_of_opaque
  27:     0x7faaf713aed1 - rustc_query_impl[1357963d8dd30e8b]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[1357963d8dd30e8b]::query_impl::type_of_opaque::dynamic_query::{closure#2}::{closure#0}, rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 8usize]>>
  28:     0x7faaf6023bb6 - rustc_query_system[887bb79932b1d8c1]::query::plumbing::try_execute_query::<rustc_query_impl[1357963d8dd30e8b]::DynamicConfig<rustc_query_system[887bb79932b1d8c1]::query::caches::DefIdCache<rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[1357963d8dd30e8b]::plumbing::QueryCtxt, false>
  29:     0x7faaf72137f5 - rustc_query_impl[1357963d8dd30e8b]::query_impl::type_of_opaque::get_query_non_incr::__rust_end_short_backtrace
  30:     0x7faaf64f6540 - rustc_middle[f0eb6ba890d0a9bb]::query::plumbing::query_get_at::<rustc_query_system[887bb79932b1d8c1]::query::caches::DefIdCache<rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 8usize]>>>
  31:     0x7faaf318f449 - rustc_hir_analysis[af6e6fecb0b5810e]::collect::type_of::type_of
  32:     0x7faaf6024ef2 - rustc_query_impl[1357963d8dd30e8b]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[1357963d8dd30e8b]::query_impl::type_of::dynamic_query::{closure#2}::{closure#0}, rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 8usize]>>
  33:     0x7faaf6023bb6 - rustc_query_system[887bb79932b1d8c1]::query::plumbing::try_execute_query::<rustc_query_impl[1357963d8dd30e8b]::DynamicConfig<rustc_query_system[887bb79932b1d8c1]::query::caches::DefIdCache<rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[1357963d8dd30e8b]::plumbing::QueryCtxt, false>
  34:     0x7faaf6023767 - rustc_query_impl[1357963d8dd30e8b]::query_impl::type_of::get_query_non_incr::__rust_end_short_backtrace
  35:     0x7faaf64f6540 - rustc_middle[f0eb6ba890d0a9bb]::query::plumbing::query_get_at::<rustc_query_system[887bb79932b1d8c1]::query::caches::DefIdCache<rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 8usize]>>>
  36:     0x7faaf7149109 - rustc_hir_analysis[af6e6fecb0b5810e]::check::check::check_item_type
  37:     0x7faaf3885a93 - rustc_hir_analysis[af6e6fecb0b5810e]::check::wfcheck::check_well_formed
  38:     0x7faaf63ef1c7 - rustc_query_impl[1357963d8dd30e8b]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[1357963d8dd30e8b]::query_impl::check_well_formed::dynamic_query::{closure#2}::{closure#0}, rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 1usize]>>
  39:     0x7faaf63ee919 - rustc_query_system[887bb79932b1d8c1]::query::plumbing::try_execute_query::<rustc_query_impl[1357963d8dd30e8b]::DynamicConfig<rustc_query_system[887bb79932b1d8c1]::query::caches::VecCache<rustc_span[db86d96c2ae2e3a4]::def_id::LocalDefId, rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[1357963d8dd30e8b]::plumbing::QueryCtxt, false>
  40:     0x7faaf63ee590 - rustc_query_impl[1357963d8dd30e8b]::query_impl::check_well_formed::get_query_non_incr::__rust_end_short_backtrace
  41:     0x7faaf63ef247 - rustc_middle[f0eb6ba890d0a9bb]::query::plumbing::query_ensure_error_guaranteed::<rustc_query_system[887bb79932b1d8c1]::query::caches::VecCache<rustc_span[db86d96c2ae2e3a4]::def_id::LocalDefId, rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 1usize]>>, ()>
  42:     0x7faaf63ef7f2 - rustc_hir_analysis[af6e6fecb0b5810e]::check::wfcheck::check_mod_type_wf
  43:     0x7faaf63ef26f - rustc_query_impl[1357963d8dd30e8b]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[1357963d8dd30e8b]::query_impl::check_mod_type_wf::dynamic_query::{closure#2}::{closure#0}, rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 1usize]>>
  44:     0x7faaf6bed0c1 - rustc_query_system[887bb79932b1d8c1]::query::plumbing::try_execute_query::<rustc_query_impl[1357963d8dd30e8b]::DynamicConfig<rustc_query_system[887bb79932b1d8c1]::query::caches::DefaultCache<rustc_span[db86d96c2ae2e3a4]::def_id::LocalModDefId, rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[1357963d8dd30e8b]::plumbing::QueryCtxt, false>
  45:     0x7faaf6bece70 - rustc_query_impl[1357963d8dd30e8b]::query_impl::check_mod_type_wf::get_query_non_incr::__rust_end_short_backtrace
  46:     0x7faaf671f42f - rustc_hir_analysis[af6e6fecb0b5810e]::check_crate
  47:     0x7faaf6868aca - rustc_interface[5fea8bf9cd0b71b5]::passes::run_required_analyses
  48:     0x7faaf6e0861e - rustc_interface[5fea8bf9cd0b71b5]::passes::analysis
  49:     0x7faaf6e085ef - rustc_query_impl[1357963d8dd30e8b]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[1357963d8dd30e8b]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 1usize]>>
  50:     0x7faaf6f92cee - rustc_query_system[887bb79932b1d8c1]::query::plumbing::try_execute_query::<rustc_query_impl[1357963d8dd30e8b]::DynamicConfig<rustc_query_system[887bb79932b1d8c1]::query::caches::SingleCache<rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[1357963d8dd30e8b]::plumbing::QueryCtxt, false>
  51:     0x7faaf6f929ce - rustc_query_impl[1357963d8dd30e8b]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  52:     0x7faaf6e8707a - rustc_interface[5fea8bf9cd0b71b5]::interface::run_compiler::<core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>, rustc_driver_impl[945e9afaf49c7d35]::run_compiler::{closure#0}>::{closure#1}
  53:     0x7faaf6ecd5d0 - std[56fe22ad9ea837fd]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[5fea8bf9cd0b71b5]::util::run_in_thread_with_globals<rustc_interface[5fea8bf9cd0b71b5]::util::run_in_thread_pool_with_globals<rustc_interface[5fea8bf9cd0b71b5]::interface::run_compiler<core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>, rustc_driver_impl[945e9afaf49c7d35]::run_compiler::{closure#0}>::{closure#1}, core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>>::{closure#0}, core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>>
  54:     0x7faaf6ecd9eb - <<std[56fe22ad9ea837fd]::thread::Builder>::spawn_unchecked_<rustc_interface[5fea8bf9cd0b71b5]::util::run_in_thread_with_globals<rustc_interface[5fea8bf9cd0b71b5]::util::run_in_thread_pool_with_globals<rustc_interface[5fea8bf9cd0b71b5]::interface::run_compiler<core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>, rustc_driver_impl[945e9afaf49c7d35]::run_compiler::{closure#0}>::{closure#1}, core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>>::{closure#0}, core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>>::{closure#1} as core[5ba82ee3405aa490]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  55:     0x7faaf6ece4b9 - std::sys::pal::unix::thread::Thread::new::thread_start::hb3d6392adeea417c
  56:     0x7faaf106bac3 - start_thread
                               at ./nptl/pthread_create.c:442:8
  57:     0x7faaf10fd850 - __GI___clone3
                               at ./misc/../sysdeps/unix/sysv/linux/x86_64/clone3.S:81
  58:                0x0 - <unknown>

[cyrgani]

Reduced:

trait Trait {}
impl<'a> Trait for () {
    fn pass2<'a>() -> impl Trait2 {}
}

trait Trait2 {}
impl Trait2 for () {}

[matthiaskrgr]

might be duplicate of one of these: https://github.com/rust-lang/rust/issues?q=is%3Aissue%20state%3Aopen%20%22to%20a%20region%20vid%22%20

[compiler-errors]

This looks like a modified version of tests/ui/inference/ice-ifer-var-leaked-out-of-rollback-122098.rs. It would be nice to indicate that you minimized it from an existing test in the future.