ICE: assertion failure: `Size(0 bytes` / `8 bytes)` `rustc_const_eval/src/interpret/place.rs`

[matthiaskrgr]

Code

#![feature(const_trait_impl)]

#[const_trait]
trait Func<T> {
    type Output;

    fn call_once(self, arg: T) -> Self::Output;
}

struct Closure;

impl const Func<&usize> for Closure {
    type Output = usize;

    fn call_once(&'static self, arg: &usize) -> Self::Output {
        *arg
    }
}

enum Bug<T = [(); Closure.call_once(&0)]> {
    V(T),
}

Meta

rustc --version --verbose:

rustc 1.72.0-nightly (371994e0d 2023-06-13)
binary: rustc
commit-hash: 371994e0d8380600ddda78ca1be937c7fb179b49
commit-date: 2023-06-13
host: x86_64-unknown-linux-gnu
release: 1.72.0-nightly
LLVM version: 16.0.5

Error output

-

Backtrace

thread 'rustc' panicked at 'assertion failed: `(left == right)`
  left: `Size(0 bytes)`,
 right: `Size(8 bytes)`', compiler/rustc_const_eval/src/interpret/place.rs:667:17
stack backtrace:
   0:     0x7ff7291a2c41 - std::backtrace_rs::backtrace::libunwind::trace::h4e5cd7155e2ebaac
                               at /rustc/371994e0d8380600ddda78ca1be937c7fb179b49/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5
   1:     0x7ff7291a2c41 - std::backtrace_rs::backtrace::trace_unsynchronized::hb4d504f8def07b70
                               at /rustc/371994e0d8380600ddda78ca1be937c7fb179b49/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7ff7291a2c41 - std::sys_common::backtrace::_print_fmt::h270ee65403a6a640
                               at /rustc/371994e0d8380600ddda78ca1be937c7fb179b49/library/std/src/sys_common/backtrace.rs:65:5
   3:     0x7ff7291a2c41 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hfa127bbe4d370ae8
                               at /rustc/371994e0d8380600ddda78ca1be937c7fb179b49/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x7ff7292035ff - core::fmt::rt::Argument::fmt::h975c0825ea1bb836
                               at /rustc/371994e0d8380600ddda78ca1be937c7fb179b49/library/core/src/fmt/rt.rs:138:9
   5:     0x7ff7292035ff - core::fmt::write::hb200bbda235147d0
                               at /rustc/371994e0d8380600ddda78ca1be937c7fb179b49/library/core/src/fmt/mod.rs:1094:21
   6:     0x7ff729195ee1 - std::io::Write::write_fmt::hf4eeaa80392fd692
                               at /rustc/371994e0d8380600ddda78ca1be937c7fb179b49/library/std/src/io/mod.rs:1713:15
   7:     0x7ff7291a2a55 - std::sys_common::backtrace::_print::h2427e2e0721aca68
                               at /rustc/371994e0d8380600ddda78ca1be937c7fb179b49/library/std/src/sys_common/backtrace.rs:47:5
   8:     0x7ff7291a2a55 - std::sys_common::backtrace::print::h8c074174f5a65b94
                               at /rustc/371994e0d8380600ddda78ca1be937c7fb179b49/library/std/src/sys_common/backtrace.rs:34:9
   9:     0x7ff7291a5737 - std::panicking::default_hook::{{closure}}::habdecd03f278805d
  10:     0x7ff7291a5524 - std::panicking::default_hook::hfeee4c9ec6e7984a
                               at /rustc/371994e0d8380600ddda78ca1be937c7fb179b49/library/std/src/panicking.rs:288:9
  11:     0x7ff727fef46b - rustc_driver_impl[82ed5c687fa14bc7]::install_ice_hook::{closure#0}
  12:     0x7ff7291a5e7d - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::h75ee17e40156a9b1
                               at /rustc/371994e0d8380600ddda78ca1be937c7fb179b49/library/alloc/src/boxed.rs:1999:9
  13:     0x7ff7291a5e7d - std::panicking::rust_panic_with_hook::h50748255142a0809
                               at /rustc/371994e0d8380600ddda78ca1be937c7fb179b49/library/std/src/panicking.rs:709:13
  14:     0x7ff7291a5c17 - std::panicking::begin_panic_handler::{{closure}}::h1532befb1017034b
                               at /rustc/371994e0d8380600ddda78ca1be937c7fb179b49/library/std/src/panicking.rs:597:13
  15:     0x7ff7291a3076 - std::sys_common::backtrace::__rust_end_short_backtrace::h36f919598d3260ac
                               at /rustc/371994e0d8380600ddda78ca1be937c7fb179b49/library/std/src/sys_common/backtrace.rs:151:18
  16:     0x7ff7291a5962 - rust_begin_unwind
                               at /rustc/371994e0d8380600ddda78ca1be937c7fb179b49/library/std/src/panicking.rs:593:5
  17:     0x7ff7291ff883 - core::panicking::panic_fmt::h637089c9b9878b43
                               at /rustc/371994e0d8380600ddda78ca1be937c7fb179b49/library/core/src/panicking.rs:67:14
  18:     0x7ff7291ffd2b - core::panicking::assert_failed_inner::h19f040ba3a8153bc
  19:     0x7ff727f3c00c - core[c5a351271e0d68a3]::panicking::assert_failed::<rustc_abi[dfec205f4ad3b685]::Size, rustc_abi[dfec205f4ad3b685]::Size>
  20:     0x7ff726481aa8 - <rustc_const_eval[31d57a31448f4b0]::interpret::eval_context::InterpCx<rustc_const_eval[31d57a31448f4b0]::const_eval::machine::CompileTimeInterpreter>>::pass_argument::<core[c5a351271e0d68a3]::iter::adapters::filter::Filter<core[c5a351271e0d68a3]::iter::adapters::zip::Zip<core[c5a351271e0d68a3]::slice::iter::Iter<rustc_const_eval[31d57a31448f4b0]::interpret::operand::OpTy>, core[c5a351271e0d68a3]::slice::iter::Iter<rustc_target[97a646c7007a6648]::abi::call::ArgAbi<rustc_middle[cf9791794388bff2]::ty::Ty>>>, <rustc_const_eval[31d57a31448f4b0]::interpret::eval_context::InterpCx<rustc_const_eval[31d57a31448f4b0]::const_eval::machine::CompileTimeInterpreter>>::eval_fn_call::{closure#2}>>
  21:     0x7ff726460066 - <rustc_const_eval[31d57a31448f4b0]::interpret::eval_context::InterpCx<rustc_const_eval[31d57a31448f4b0]::const_eval::machine::CompileTimeInterpreter>>::eval_fn_call
  22:     0x7ff726450a61 - <rustc_const_eval[31d57a31448f4b0]::interpret::eval_context::InterpCx<rustc_const_eval[31d57a31448f4b0]::const_eval::machine::CompileTimeInterpreter>>::terminator
  23:     0x7ff7263c5068 - rustc_const_eval[31d57a31448f4b0]::const_eval::eval_queries::eval_to_allocation_raw_provider
  24:     0x7ff726077537 - rustc_query_impl[eec84043af3db326]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[eec84043af3db326]::query_impl::eval_to_allocation_raw::dynamic_query::{closure#2}::{closure#0}, rustc_middle[cf9791794388bff2]::query::erase::Erased<[u8; 16usize]>>
  25:     0x7ff726c7eb4c - rustc_query_system[558b060458ea38]::query::plumbing::try_execute_query::<rustc_query_impl[eec84043af3db326]::DynamicConfig<rustc_query_system[558b060458ea38]::query::caches::DefaultCache<rustc_middle[cf9791794388bff2]::ty::ParamEnvAnd<rustc_middle[cf9791794388bff2]::mir::interpret::GlobalId>, rustc_middle[cf9791794388bff2]::query::erase::Erased<[u8; 16usize]>>, false, false, false>, rustc_query_impl[eec84043af3db326]::plumbing::QueryCtxt, false>
  26:     0x7ff726c7e80d - rustc_query_impl[eec84043af3db326]::query_impl::eval_to_allocation_raw::get_query_non_incr::__rust_end_short_backtrace
  27:     0x7ff7263c3fe2 - rustc_const_eval[31d57a31448f4b0]::const_eval::eval_queries::eval_to_allocation_raw_provider
  28:     0x7ff726077537 - rustc_query_impl[eec84043af3db326]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[eec84043af3db326]::query_impl::eval_to_allocation_raw::dynamic_query::{closure#2}::{closure#0}, rustc_middle[cf9791794388bff2]::query::erase::Erased<[u8; 16usize]>>
  29:     0x7ff726c7eb4c - rustc_query_system[558b060458ea38]::query::plumbing::try_execute_query::<rustc_query_impl[eec84043af3db326]::DynamicConfig<rustc_query_system[558b060458ea38]::query::caches::DefaultCache<rustc_middle[cf9791794388bff2]::ty::ParamEnvAnd<rustc_middle[cf9791794388bff2]::mir::interpret::GlobalId>, rustc_middle[cf9791794388bff2]::query::erase::Erased<[u8; 16usize]>>, false, false, false>, rustc_query_impl[eec84043af3db326]::plumbing::QueryCtxt, false>
  30:     0x7ff726c7e80d - rustc_query_impl[eec84043af3db326]::query_impl::eval_to_allocation_raw::get_query_non_incr::__rust_end_short_backtrace
  31:     0x7ff727732518 - rustc_const_eval[31d57a31448f4b0]::const_eval::eval_to_valtree
  32:     0x7ff727732370 - <rustc_const_eval[31d57a31448f4b0]::provide::{closure#0} as core[c5a351271e0d68a3]::ops::function::FnOnce<(rustc_middle[cf9791794388bff2]::ty::context::TyCtxt, rustc_middle[cf9791794388bff2]::ty::ParamEnvAnd<rustc_middle[cf9791794388bff2]::mir::interpret::GlobalId>)>>::call_once
  33:     0x7ff72740efa9 - rustc_query_impl[eec84043af3db326]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[eec84043af3db326]::query_impl::eval_to_valtree::dynamic_query::{closure#2}::{closure#0}, rustc_middle[cf9791794388bff2]::query::erase::Erased<[u8; 24usize]>>
  34:     0x7ff72740ef58 - <rustc_query_impl[eec84043af3db326]::query_impl::eval_to_valtree::dynamic_query::{closure#2} as core[c5a351271e0d68a3]::ops::function::FnOnce<(rustc_middle[cf9791794388bff2]::ty::context::TyCtxt, rustc_middle[cf9791794388bff2]::ty::ParamEnvAnd<rustc_middle[cf9791794388bff2]::mir::interpret::GlobalId>)>>::call_once
  35:     0x7ff7275ca408 - rustc_query_system[558b060458ea38]::query::plumbing::try_execute_query::<rustc_query_impl[eec84043af3db326]::DynamicConfig<rustc_query_system[558b060458ea38]::query::caches::DefaultCache<rustc_middle[cf9791794388bff2]::ty::ParamEnvAnd<rustc_middle[cf9791794388bff2]::mir::interpret::GlobalId>, rustc_middle[cf9791794388bff2]::query::erase::Erased<[u8; 24usize]>>, false, false, false>, rustc_query_impl[eec84043af3db326]::plumbing::QueryCtxt, false>
  36:     0x7ff7275ca0ed - rustc_query_impl[eec84043af3db326]::query_impl::eval_to_valtree::get_query_non_incr::__rust_end_short_backtrace
  37:     0x7ff7266f72fc - rustc_middle[cf9791794388bff2]::query::plumbing::query_get_at::<rustc_query_system[558b060458ea38]::query::caches::DefaultCache<rustc_middle[cf9791794388bff2]::ty::ParamEnvAnd<rustc_middle[cf9791794388bff2]::mir::interpret::GlobalId>, rustc_middle[cf9791794388bff2]::query::erase::Erased<[u8; 24usize]>>>
  38:     0x7ff7266f7003 - <rustc_middle[cf9791794388bff2]::ty::context::TyCtxt>::const_eval_global_id_for_typeck
  39:     0x7ff7266f6bbc - <rustc_middle[cf9791794388bff2]::ty::context::TyCtxt>::const_eval_resolve_for_typeck
  40:     0x7ff7266f389f - <rustc_middle[cf9791794388bff2]::ty::consts::Const>::eval
  41:     0x7ff7266f2bd4 - <rustc_trait_selection[289a0623b6a0d732]::traits::project::AssocTypeNormalizer as rustc_type_ir[5f458fb36e5c0deb]::fold::TypeFolder<rustc_middle[cf9791794388bff2]::ty::context::TyCtxt>>::fold_const
  42:     0x7ff7266d26c2 - <rustc_trait_selection[289a0623b6a0d732]::traits::project::AssocTypeNormalizer as rustc_type_ir[5f458fb36e5c0deb]::fold::TypeFolder<rustc_middle[cf9791794388bff2]::ty::context::TyCtxt>>::fold_ty
  43:     0x7ff726e1c559 - <&rustc_middle[cf9791794388bff2]::ty::list::List<rustc_middle[cf9791794388bff2]::ty::subst::GenericArg> as rustc_type_ir[5f458fb36e5c0deb]::fold::TypeFoldable<rustc_middle[cf9791794388bff2]::ty::context::TyCtxt>>::try_fold_with::<rustc_trait_selection[289a0623b6a0d732]::traits::project::AssocTypeNormalizer>
  44:     0x7ff726e1c256 - <rustc_trait_selection[289a0623b6a0d732]::traits::project::AssocTypeNormalizer as rustc_type_ir[5f458fb36e5c0deb]::fold::FallibleTypeFolder<rustc_middle[cf9791794388bff2]::ty::context::TyCtxt>>::try_fold_binder::<rustc_middle[cf9791794388bff2]::ty::PredicateKind>
  45:     0x7ff726e1bf1c - <rustc_trait_selection[289a0623b6a0d732]::traits::project::AssocTypeNormalizer as rustc_type_ir[5f458fb36e5c0deb]::fold::FallibleTypeFolder<rustc_middle[cf9791794388bff2]::ty::context::TyCtxt>>::try_fold_predicate
  46:     0x7ff726e1b9cb - <rustc_infer[91049bb12f28370c]::infer::at::At as rustc_trait_selection[289a0623b6a0d732]::traits::project::NormalizeExt>::normalize::<rustc_middle[cf9791794388bff2]::ty::Predicate>
  47:     0x7ff726e1b5bd - <rustc_trait_selection[289a0623b6a0d732]::traits::engine::ObligationCtxt>::normalize::<rustc_middle[cf9791794388bff2]::ty::Predicate>
  48:     0x7ff726b5926d - <&mut rustc_hir_analysis[e462668682978bb5]::check::wfcheck::check_where_clauses::{closure#3} as core[c5a351271e0d68a3]::ops::function::FnOnce<((rustc_middle[cf9791794388bff2]::ty::Predicate, rustc_span[5b25b58355c0a00e]::span_encoding::Span),)>>::call_once
  49:     0x7ff726b4c8c4 - <alloc[a8c9cd47032004ef]::vec::Vec<rustc_infer[91049bb12f28370c]::traits::Obligation<rustc_middle[cf9791794388bff2]::ty::Predicate>> as alloc[a8c9cd47032004ef]::vec::spec_from_iter::SpecFromIter<rustc_infer[91049bb12f28370c]::traits::Obligation<rustc_middle[cf9791794388bff2]::ty::Predicate>, core[c5a351271e0d68a3]::iter::adapters::chain::Chain<core[c5a351271e0d68a3]::iter::adapters::flatten::FlatMap<core[c5a351271e0d68a3]::iter::adapters::zip::Zip<alloc[a8c9cd47032004ef]::vec::into_iter::IntoIter<rustc_middle[cf9791794388bff2]::ty::Predicate>, alloc[a8c9cd47032004ef]::vec::into_iter::IntoIter<rustc_span[5b25b58355c0a00e]::span_encoding::Span>>, alloc[a8c9cd47032004ef]::vec::Vec<rustc_infer[91049bb12f28370c]::traits::Obligation<rustc_middle[cf9791794388bff2]::ty::Predicate>>, rustc_hir_analysis[e462668682978bb5]::check::wfcheck::check_where_clauses::{closure#4}>, core[c5a351271e0d68a3]::iter::adapters::map::Map<core[c5a351271e0d68a3]::iter::adapters::flatten::FlatMap<core[c5a351271e0d68a3]::slice::iter::Iter<(rustc_middle[cf9791794388bff2]::ty::Predicate, rustc_span[5b25b58355c0a00e]::span_encoding::Span)>, core[c5a351271e0d68a3]::option::Option<(rustc_middle[cf9791794388bff2]::ty::Predicate, rustc_span[5b25b58355c0a00e]::span_encoding::Span)>, rustc_hir_analysis[e462668682978bb5]::check::wfcheck::check_where_clauses::{closure#2}>, rustc_hir_analysis[e462668682978bb5]::check::wfcheck::check_where_clauses::{closure#3}>>>>::from_iter
  50:     0x7ff726b49b1c - rustc_hir_analysis[e462668682978bb5]::check::wfcheck::check_where_clauses
  51:     0x7ff726b578b5 - rustc_hir_analysis[e462668682978bb5]::check::wfcheck::check_type_defn
  52:     0x7ff726b35c2f - rustc_hir_analysis[e462668682978bb5]::check::wfcheck::check_well_formed
  53:     0x7ff725febd8c - rustc_query_impl[eec84043af3db326]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[eec84043af3db326]::query_impl::check_well_formed::dynamic_query::{closure#2}::{closure#0}, rustc_middle[cf9791794388bff2]::query::erase::Erased<[u8; 0usize]>>
  54:     0x7ff726851006 - rustc_query_system[558b060458ea38]::query::plumbing::try_execute_query::<rustc_query_impl[eec84043af3db326]::DynamicConfig<rustc_query_system[558b060458ea38]::query::caches::VecCache<rustc_hir[93dddeb8c6b4db45]::hir_id::OwnerId, rustc_middle[cf9791794388bff2]::query::erase::Erased<[u8; 0usize]>>, false, false, false>, rustc_query_impl[eec84043af3db326]::plumbing::QueryCtxt, false>
  55:     0x7ff726850d54 - rustc_query_impl[eec84043af3db326]::query_impl::check_well_formed::get_query_non_incr::__rust_end_short_backtrace
  56:     0x7ff7273bb96c - rustc_data_structures[77d4adee0611d83c]::sync::par_for_each_in::<&[rustc_hir[93dddeb8c6b4db45]::hir::ItemId], <rustc_middle[cf9791794388bff2]::hir::ModuleItems>::par_items<rustc_hir_analysis[e462668682978bb5]::check::wfcheck::check_mod_type_wf::{closure#0}>::{closure#0}>
  57:     0x7ff7273bb81a - rustc_hir_analysis[e462668682978bb5]::check::wfcheck::check_mod_type_wf
  58:     0x7ff726cc91ac - rustc_query_impl[eec84043af3db326]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[eec84043af3db326]::query_impl::check_mod_type_wf::dynamic_query::{closure#2}::{closure#0}, rustc_middle[cf9791794388bff2]::query::erase::Erased<[u8; 0usize]>>
  59:     0x7ff726cc918e - <rustc_query_impl[eec84043af3db326]::query_impl::check_mod_type_wf::dynamic_query::{closure#2} as core[c5a351271e0d68a3]::ops::function::FnOnce<(rustc_middle[cf9791794388bff2]::ty::context::TyCtxt, rustc_span[5b25b58355c0a00e]::def_id::LocalDefId)>>::call_once
  60:     0x7ff72673417f - rustc_query_system[558b060458ea38]::query::plumbing::try_execute_query::<rustc_query_impl[eec84043af3db326]::DynamicConfig<rustc_query_system[558b060458ea38]::query::caches::VecCache<rustc_span[5b25b58355c0a00e]::def_id::LocalDefId, rustc_middle[cf9791794388bff2]::query::erase::Erased<[u8; 0usize]>>, false, false, false>, rustc_query_impl[eec84043af3db326]::plumbing::QueryCtxt, false>
  61:     0x7ff7279744c4 - rustc_query_impl[eec84043af3db326]::query_impl::check_mod_type_wf::get_query_non_incr::__rust_end_short_backtrace
  62:     0x7ff7274894a7 - rustc_data_structures[77d4adee0611d83c]::sync::par_for_each_in::<&[rustc_hir[93dddeb8c6b4db45]::hir_id::OwnerId], <rustc_middle[cf9791794388bff2]::hir::map::Map>::par_for_each_module<rustc_hir_analysis[e462668682978bb5]::check_crate::{closure#5}::{closure#0}::{closure#0}>::{closure#0}>
  63:     0x7ff727489277 - <rustc_session[c89a0e04955a4434]::session::Session>::track_errors::<rustc_hir_analysis[e462668682978bb5]::check_crate::{closure#5}, ()>
  64:     0x7ff7274867bf - rustc_hir_analysis[e462668682978bb5]::check_crate
  65:     0x7ff727480edd - rustc_interface[5fbdb9547dedf44d]::passes::analysis
  66:     0x7ff72750732a - rustc_query_impl[eec84043af3db326]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[eec84043af3db326]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[cf9791794388bff2]::query::erase::Erased<[u8; 1usize]>>
  67:     0x7ff727507319 - <rustc_query_impl[eec84043af3db326]::query_impl::analysis::dynamic_query::{closure#2} as core[c5a351271e0d68a3]::ops::function::FnOnce<(rustc_middle[cf9791794388bff2]::ty::context::TyCtxt, ())>>::call_once
  68:     0x7ff727689938 - rustc_query_system[558b060458ea38]::query::plumbing::try_execute_query::<rustc_query_impl[eec84043af3db326]::DynamicConfig<rustc_query_system[558b060458ea38]::query::caches::SingleCache<rustc_middle[cf9791794388bff2]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[eec84043af3db326]::plumbing::QueryCtxt, false>
  69:     0x7ff727689709 - rustc_query_impl[eec84043af3db326]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  70:     0x7ff727660255 - <rustc_middle[cf9791794388bff2]::ty::context::GlobalCtxt>::enter::<rustc_driver_impl[82ed5c687fa14bc7]::run_compiler::{closure#1}::{closure#2}::{closure#4}, core[c5a351271e0d68a3]::result::Result<(), rustc_span[5b25b58355c0a00e]::ErrorGuaranteed>>
  71:     0x7ff7272bffdf - <rustc_interface[5fbdb9547dedf44d]::interface::Compiler>::enter::<rustc_driver_impl[82ed5c687fa14bc7]::run_compiler::{closure#1}::{closure#2}, core[c5a351271e0d68a3]::result::Result<core[c5a351271e0d68a3]::option::Option<rustc_interface[5fbdb9547dedf44d]::queries::Linker>, rustc_span[5b25b58355c0a00e]::ErrorGuaranteed>>
  72:     0x7ff7272bdb79 - <scoped_tls[c0707037e0f60a9b]::ScopedKey<rustc_span[5b25b58355c0a00e]::SessionGlobals>>::set::<rustc_interface[5fbdb9547dedf44d]::interface::run_compiler<core[c5a351271e0d68a3]::result::Result<(), rustc_span[5b25b58355c0a00e]::ErrorGuaranteed>, rustc_driver_impl[82ed5c687fa14bc7]::run_compiler::{closure#1}>::{closure#0}, core[c5a351271e0d68a3]::result::Result<(), rustc_span[5b25b58355c0a00e]::ErrorGuaranteed>>
  73:     0x7ff7272bcfe6 - std[cd097dad4f2506ec]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[5fbdb9547dedf44d]::util::run_in_thread_pool_with_globals<rustc_interface[5fbdb9547dedf44d]::interface::run_compiler<core[c5a351271e0d68a3]::result::Result<(), rustc_span[5b25b58355c0a00e]::ErrorGuaranteed>, rustc_driver_impl[82ed5c687fa14bc7]::run_compiler::{closure#1}>::{closure#0}, core[c5a351271e0d68a3]::result::Result<(), rustc_span[5b25b58355c0a00e]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[c5a351271e0d68a3]::result::Result<(), rustc_span[5b25b58355c0a00e]::ErrorGuaranteed>>
  74:     0x7ff7272bcd95 - <<std[cd097dad4f2506ec]::thread::Builder>::spawn_unchecked_<rustc_interface[5fbdb9547dedf44d]::util::run_in_thread_pool_with_globals<rustc_interface[5fbdb9547dedf44d]::interface::run_compiler<core[c5a351271e0d68a3]::result::Result<(), rustc_span[5b25b58355c0a00e]::ErrorGuaranteed>, rustc_driver_impl[82ed5c687fa14bc7]::run_compiler::{closure#1}>::{closure#0}, core[c5a351271e0d68a3]::result::Result<(), rustc_span[5b25b58355c0a00e]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[c5a351271e0d68a3]::result::Result<(), rustc_span[5b25b58355c0a00e]::ErrorGuaranteed>>::{closure#1} as core[c5a351271e0d68a3]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  75:     0x7ff7291b03a5 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::hae3241ec192e9c95
                               at /rustc/371994e0d8380600ddda78ca1be937c7fb179b49/library/alloc/src/boxed.rs:1985:9
  76:     0x7ff7291b03a5 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h75f69d4e89077470
                               at /rustc/371994e0d8380600ddda78ca1be937c7fb179b49/library/alloc/src/boxed.rs:1985:9
  77:     0x7ff7291b03a5 - std::sys::unix::thread::Thread::new::thread_start::heddaad8550613863
                               at /rustc/371994e0d8380600ddda78ca1be937c7fb179b49/library/std/src/sys/unix/thread.rs:108:17
  78:     0x7ff724c9b44b - <unknown>
  79:     0x7ff724d1ee40 - <unknown>
  80:                0x0 - <unknown>

error: the compiler unexpectedly panicked. this is a bug.

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 1.72.0-nightly (371994e0d 2023-06-13) running on x86_64-unknown-linux-gnu

note: compiler flags: --crate-type lib

query stack during panic:
#0 [eval_to_allocation_raw] const-evaluating + checking `Bug::{constant#0}`
#1 [eval_to_allocation_raw] const-evaluating + checking `Bug::{constant#0}`
#2 [eval_to_valtree] evaluating type-level constant
#3 [check_well_formed] checking that `Bug` is well-formed
#4 [check_mod_type_wf] checking that types are well-formed in top-level module
#5 [analysis] running analysis passes on this crate
end of query stack

[matthiaskrgr]

Regression in nightly-2022-05-28

  commit[0] 2022-05-26: Auto merge of #97434 - matthiaskrgr:rollup-7j3y16l, r=matthiaskrgr
  commit[1] 2022-05-26: Auto merge of #97386 - nnethercote:optimize-pos-adjustments, r=bjorn3
  commit[2] 2022-05-27: Auto merge of #96298 - petrochenkov:fromgen, r=estebank
  commit[3] 2022-05-27: Auto merge of #97444 - compiler-errors:rollup-2gvdav6, r=compiler-errors
  commit[4] 2022-05-27: Auto merge of #97004 - nnethercote:proc-macro-tweaks, r=eddyb
  commit[5] 2022-05-27: Auto merge of #97442 - hafeoz:master, r=GuillaumeGomez
  commit[6] 2022-05-27: Auto merge of #96046 - oli-obk:const_typeck, r=cjgillot
  commit[7] 2022-05-27: Auto merge of #96790 - lqd:update_jemalloc, r=Mark-Simulacrum
  

[clubby789]

The issue seems to be that const_trait doesn't check that the impl function signature matches the trait function signature (until after const eval, at least), so it allows us to pass &T to an ABI expecting a T. e.g.

#![feature(const_trait_impl)]

#[const_trait]
trait Func {
    fn trigger(self) -> usize;
}

struct Cls;

impl const Func for Cls {
    fn trigger(&self, a: usize) -> usize {
        0
    }
}

enum Bug<T = [(); Cls.trigger()]> {
    V(T),
}

This ICEs with a mismatch in the number of args

wf_checking, which evaluates Cls.trigger() runs after item_types_checking which does report the mismatch

[JohnTitor]

Fixed on the latest nightly, marking as E-needs-test (or, feel free to close if we have a sufficient regression test)
@rustbot labels: +E-needs-test

[matthiaskrgr]

auto-reduced (treereduce-rust):

#![feature(const_trait_impl, effects)]

#[const_trait]
trait Value {
    fn value() -> u32;
}

const fn get_value<T: ~const Value>() -> u32 {
    T::value()
}

struct FortyTwo;

impl const Value for FortyTwo {
    fn value() -> i64 {
        42
    }
}

const FORTY_TWO: u32 = get_value::<FortyTwo>();

fn main() {
    assert_eq!(FORTY_TWO, 42);
}

original:

// Tests that a const default trait impl can be specialized by another const
// trait impl and that the specializing impl will be used during const-eval.

// run-pass

#![feature(const_trait_impl, effects)]
#![feature(min_specialization)]

#[const_trait]
trait Value {
    fn value() -> u32;
}

const fn get_value<T: ~const Value>() -> u32 {
    T::value()
}

impl<T> const Value for T {
    default fn value() -> u32 {
        0
    }
}

struct FortyTwo;

impl const Value for FortyTwo {
    fn value() -> i64 {
        42
    }
}

const ZERO: u32 = get_value::<()>();

const FORTY_TWO: u32 = get_value::<FortyTwo>();

fn main() {
    assert_eq!(ZERO, 0);
    assert_eq!(FORTY_TWO, 42);
}

Version information

rustc 1.78.0-nightly (b381d3ab2 2024-02-12)
binary: rustc
commit-hash: b381d3ab27f788f990551100c4425bb782d26d76
commit-date: 2024-02-12
host: x86_64-unknown-linux-gnu
release: 1.78.0-nightly
LLVM version: 17.0.6

Command:
/home/matthias/.rustup/toolchains/master/bin/rustc

Program output

error[E0053]: method `value` has an incompatible type for trait
  --> /tmp/icemaker_global_tempdir.r53dfo7rqFNJ/rustc_testrunner_tmpdir_reporting.fKjNRjvMAypS/mvce.rs:15:19
   |
15 |     fn value() -> i64 {
   |                   ^^^
   |                   |
   |                   expected `u32`, found `i64`
   |                   help: change the output type to match the trait: `u32`
   |
note: type in trait
  --> /tmp/icemaker_global_tempdir.r53dfo7rqFNJ/rustc_testrunner_tmpdir_reporting.fKjNRjvMAypS/mvce.rs:5:19
   |
5  |     fn value() -> u32;
   |                   ^^^
   = note: expected signature `fn() -> u32`
              found signature `fn() -> i64`

thread 'rustc' panicked at compiler/rustc_const_eval/src/interpret/place.rs:817:17:
assertion `left == right` failed
  left: Size(8 bytes)
 right: Size(4 bytes)
stack backtrace:
   0:     0x7f12ebba2476 - std::backtrace_rs::backtrace::libunwind::trace::h3f288a3148e8bb15
                               at /rustc/b381d3ab27f788f990551100c4425bb782d26d76/library/std/src/../../backtrace/src/backtrace/libunwind.rs:104:5
   1:     0x7f12ebba2476 - std::backtrace_rs::backtrace::trace_unsynchronized::h7277353061928bc0
                               at /rustc/b381d3ab27f788f990551100c4425bb782d26d76/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7f12ebba2476 - std::sys_common::backtrace::_print_fmt::hbf79f06a8c92ca0e
                               at /rustc/b381d3ab27f788f990551100c4425bb782d26d76/library/std/src/sys_common/backtrace.rs:68:5
   3:     0x7f12ebba2476 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h0afd1ff8e38a8a84
                               at /rustc/b381d3ab27f788f990551100c4425bb782d26d76/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x7f12ebbf5030 - core::fmt::rt::Argument::fmt::h7f26a9b6a6522b09
                               at /rustc/b381d3ab27f788f990551100c4425bb782d26d76/library/core/src/fmt/rt.rs:142:9
   5:     0x7f12ebbf5030 - core::fmt::write::he7de9de816f98016
                               at /rustc/b381d3ab27f788f990551100c4425bb782d26d76/library/core/src/fmt/mod.rs:1120:17
   6:     0x7f12ebb95c6f - std::io::Write::write_fmt::h38e65bf4265dc66c
                               at /rustc/b381d3ab27f788f990551100c4425bb782d26d76/library/std/src/io/mod.rs:1854:15
   7:     0x7f12ebba2254 - std::sys_common::backtrace::_print::hf1424a842a74edeb
                               at /rustc/b381d3ab27f788f990551100c4425bb782d26d76/library/std/src/sys_common/backtrace.rs:47:5
   8:     0x7f12ebba2254 - std::sys_common::backtrace::print::hbb43acdb160822bd
                               at /rustc/b381d3ab27f788f990551100c4425bb782d26d76/library/std/src/sys_common/backtrace.rs:34:9
   9:     0x7f12ebba5047 - std::panicking::default_hook::{{closure}}::h9c602a562527e529
  10:     0x7f12ebba4da9 - std::panicking::default_hook::h9cb3bf5f6c73326f
                               at /rustc/b381d3ab27f788f990551100c4425bb782d26d76/library/std/src/panicking.rs:292:9
  11:     0x7f12e895cfdc - std[73253c920228642]::panicking::update_hook::<alloc[940273873142bb35]::boxed::Box<rustc_driver_impl[f037f419b039420a]::install_ice_hook::{closure#0}>>::{closure#0}
  12:     0x7f12ebba5796 - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::h1e0fe9ec90d27cc3
                               at /rustc/b381d3ab27f788f990551100c4425bb782d26d76/library/alloc/src/boxed.rs:2030:9
  13:     0x7f12ebba5796 - std::panicking::rust_panic_with_hook::hb5ad56797fd964c4
                               at /rustc/b381d3ab27f788f990551100c4425bb782d26d76/library/std/src/panicking.rs:785:13
  14:     0x7f12ebba54e2 - std::panicking::begin_panic_handler::{{closure}}::hd364aeee29433213
                               at /rustc/b381d3ab27f788f990551100c4425bb782d26d76/library/std/src/panicking.rs:659:13
  15:     0x7f12ebba2976 - std::sys_common::backtrace::__rust_end_short_backtrace::ha10bb1568b9ec73d
                               at /rustc/b381d3ab27f788f990551100c4425bb782d26d76/library/std/src/sys_common/backtrace.rs:171:18
  16:     0x7f12ebba5234 - rust_begin_unwind
                               at /rustc/b381d3ab27f788f990551100c4425bb782d26d76/library/std/src/panicking.rs:647:5
  17:     0x7f12ebbf1785 - core::panicking::panic_fmt::h91fa7152f33c7717
                               at /rustc/b381d3ab27f788f990551100c4425bb782d26d76/library/core/src/panicking.rs:72:14
  18:     0x7f12ebbf1ccb - core::panicking::assert_failed_inner::h57b72360e97f09d3
                               at /rustc/b381d3ab27f788f990551100c4425bb782d26d76/library/core/src/panicking.rs:342:17
  19:     0x7f12e88da0d3 - core[ed182bbac36ed604]::panicking::assert_failed::<rustc_abi[24af6b384a0c51d]::Size, rustc_abi[24af6b384a0c51d]::Size>
  20:     0x7f12ea29d97d - <rustc_const_eval[7bd60fb11925ea71]::interpret::eval_context::InterpCx<rustc_const_eval[7bd60fb11925ea71]::const_eval::machine::CompileTimeInterpreter>>::pop_stack_frame
  21:     0x7f12ea9a49ef - rustc_const_eval[7bd60fb11925ea71]::const_eval::eval_queries::eval_body_using_ecx::{closure#0}
  22:     0x7f12ea33cb30 - rustc_const_eval[7bd60fb11925ea71]::const_eval::eval_queries::eval_in_interpreter
  23:     0x7f12ea33280c - rustc_const_eval[7bd60fb11925ea71]::const_eval::eval_queries::eval_to_allocation_raw_provider
  24:     0x7f12ea33264c - rustc_query_impl[b78e7f0549dc02d3]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[b78e7f0549dc02d3]::query_impl::eval_to_allocation_raw::dynamic_query::{closure#2}::{closure#0}, rustc_middle[dbb6cff8550fbced]::query::erase::Erased<[u8; 24usize]>>
  25:     0x7f12ea3772eb - rustc_query_system[74854bfa6cddafab]::query::plumbing::try_execute_query::<rustc_query_impl[b78e7f0549dc02d3]::DynamicConfig<rustc_query_system[74854bfa6cddafab]::query::caches::DefaultCache<rustc_middle[dbb6cff8550fbced]::ty::ParamEnvAnd<rustc_middle[dbb6cff8550fbced]::mir::interpret::GlobalId>, rustc_middle[dbb6cff8550fbced]::query::erase::Erased<[u8; 24usize]>>, false, false, false>, rustc_query_impl[b78e7f0549dc02d3]::plumbing::QueryCtxt, false>
  26:     0x7f12ea376eb0 - rustc_query_impl[b78e7f0549dc02d3]::query_impl::eval_to_allocation_raw::get_query_non_incr::__rust_end_short_backtrace
  27:     0x7f12ea3785c2 - rustc_const_eval[7bd60fb11925ea71]::const_eval::eval_queries::eval_to_const_value_raw_provider
  28:     0x7f12ea3783f6 - rustc_query_impl[b78e7f0549dc02d3]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[b78e7f0549dc02d3]::query_impl::eval_to_const_value_raw::dynamic_query::{closure#2}::{closure#0}, rustc_middle[dbb6cff8550fbced]::query::erase::Erased<[u8; 24usize]>>
  29:     0x7f12ea37729d - rustc_query_system[74854bfa6cddafab]::query::plumbing::try_execute_query::<rustc_query_impl[b78e7f0549dc02d3]::DynamicConfig<rustc_query_system[74854bfa6cddafab]::query::caches::DefaultCache<rustc_middle[dbb6cff8550fbced]::ty::ParamEnvAnd<rustc_middle[dbb6cff8550fbced]::mir::interpret::GlobalId>, rustc_middle[dbb6cff8550fbced]::query::erase::Erased<[u8; 24usize]>>, false, false, false>, rustc_query_impl[b78e7f0549dc02d3]::plumbing::QueryCtxt, false>
  30:     0x7f12ea376db0 - rustc_query_impl[b78e7f0549dc02d3]::query_impl::eval_to_const_value_raw::get_query_non_incr::__rust_end_short_backtrace
  31:     0x7f12e7d289b2 - <rustc_middle[dbb6cff8550fbced]::ty::context::TyCtxt>::const_eval_resolve
  32:     0x7f12ea99bfa3 - rustc_const_eval[7bd60fb11925ea71]::const_eval::eval_queries::eval_body_using_ecx::{closure#0}
  33:     0x7f12ea33cb30 - rustc_const_eval[7bd60fb11925ea71]::const_eval::eval_queries::eval_in_interpreter
  34:     0x7f12ea33280c - rustc_const_eval[7bd60fb11925ea71]::const_eval::eval_queries::eval_to_allocation_raw_provider
  35:     0x7f12ea33264c - rustc_query_impl[b78e7f0549dc02d3]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[b78e7f0549dc02d3]::query_impl::eval_to_allocation_raw::dynamic_query::{closure#2}::{closure#0}, rustc_middle[dbb6cff8550fbced]::query::erase::Erased<[u8; 24usize]>>
  36:     0x7f12ea3772eb - rustc_query_system[74854bfa6cddafab]::query::plumbing::try_execute_query::<rustc_query_impl[b78e7f0549dc02d3]::DynamicConfig<rustc_query_system[74854bfa6cddafab]::query::caches::DefaultCache<rustc_middle[dbb6cff8550fbced]::ty::ParamEnvAnd<rustc_middle[dbb6cff8550fbced]::mir::interpret::GlobalId>, rustc_middle[dbb6cff8550fbced]::query::erase::Erased<[u8; 24usize]>>, false, false, false>, rustc_query_impl[b78e7f0549dc02d3]::plumbing::QueryCtxt, false>
  37:     0x7f12ea376eb0 - rustc_query_impl[b78e7f0549dc02d3]::query_impl::eval_to_allocation_raw::get_query_non_incr::__rust_end_short_backtrace
  38:     0x7f12ea3785c2 - rustc_const_eval[7bd60fb11925ea71]::const_eval::eval_queries::eval_to_const_value_raw_provider
  39:     0x7f12ea3783f6 - rustc_query_impl[b78e7f0549dc02d3]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[b78e7f0549dc02d3]::query_impl::eval_to_const_value_raw::dynamic_query::{closure#2}::{closure#0}, rustc_middle[dbb6cff8550fbced]::query::erase::Erased<[u8; 24usize]>>
  40:     0x7f12ea37729d - rustc_query_system[74854bfa6cddafab]::query::plumbing::try_execute_query::<rustc_query_impl[b78e7f0549dc02d3]::DynamicConfig<rustc_query_system[74854bfa6cddafab]::query::caches::DefaultCache<rustc_middle[dbb6cff8550fbced]::ty::ParamEnvAnd<rustc_middle[dbb6cff8550fbced]::mir::interpret::GlobalId>, rustc_middle[dbb6cff8550fbced]::query::erase::Erased<[u8; 24usize]>>, false, false, false>, rustc_query_impl[b78e7f0549dc02d3]::plumbing::QueryCtxt, false>
  41:     0x7f12ea376db0 - rustc_query_impl[b78e7f0549dc02d3]::query_impl::eval_to_const_value_raw::get_query_non_incr::__rust_end_short_backtrace
  42:     0x7f12e7d289b2 - <rustc_middle[dbb6cff8550fbced]::ty::context::TyCtxt>::const_eval_resolve
  43:     0x7f12e74633ca - <rustc_mir_transform[21d810ff238a01d7]::const_prop_lint::ConstPropagator as rustc_middle[dbb6cff8550fbced]::mir::visit::Visitor>::visit_operand
  44:     0x7f12e7464768 - <rustc_mir_transform[21d810ff238a01d7]::const_prop_lint::ConstPropagator as rustc_middle[dbb6cff8550fbced]::mir::visit::Visitor>::visit_assign
  45:     0x7f12ea2086c7 - <rustc_mir_transform[21d810ff238a01d7]::const_prop_lint::ConstPropagator as rustc_middle[dbb6cff8550fbced]::mir::visit::Visitor>::visit_body
  46:     0x7f12e74609ea - <rustc_mir_transform[21d810ff238a01d7]::const_prop_lint::ConstPropLint as rustc_mir_transform[21d810ff238a01d7]::pass_manager::MirLint>::run_lint
  47:     0x7f12e9c10b29 - rustc_mir_transform[21d810ff238a01d7]::pass_manager::run_passes_inner
  48:     0x7f12e7096df3 - rustc_mir_transform[21d810ff238a01d7]::mir_drops_elaborated_and_const_checked
  49:     0x7f12e9d70975 - rustc_query_impl[b78e7f0549dc02d3]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[b78e7f0549dc02d3]::query_impl::mir_drops_elaborated_and_const_checked::dynamic_query::{closure#2}::{closure#0}, rustc_middle[dbb6cff8550fbced]::query::erase::Erased<[u8; 8usize]>>
  50:     0x7f12e9d70bfa - rustc_query_system[74854bfa6cddafab]::query::plumbing::try_execute_query::<rustc_query_impl[b78e7f0549dc02d3]::DynamicConfig<rustc_query_system[74854bfa6cddafab]::query::caches::VecCache<rustc_span[a4806a91d128f927]::def_id::LocalDefId, rustc_middle[dbb6cff8550fbced]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[b78e7f0549dc02d3]::plumbing::QueryCtxt, false>
  51:     0x7f12e9d704d4 - rustc_query_impl[b78e7f0549dc02d3]::query_impl::mir_drops_elaborated_and_const_checked::get_query_non_incr::__rust_end_short_backtrace
  52:     0x7f12ea5e0988 - rustc_interface[ceb207a8fb5539d]::passes::analysis
  53:     0x7f12ea5e005f - rustc_query_impl[b78e7f0549dc02d3]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[b78e7f0549dc02d3]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[dbb6cff8550fbced]::query::erase::Erased<[u8; 1usize]>>
  54:     0x7f12eaac6064 - rustc_query_system[74854bfa6cddafab]::query::plumbing::try_execute_query::<rustc_query_impl[b78e7f0549dc02d3]::DynamicConfig<rustc_query_system[74854bfa6cddafab]::query::caches::SingleCache<rustc_middle[dbb6cff8550fbced]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[b78e7f0549dc02d3]::plumbing::QueryCtxt, false>
  55:     0x7f12eaac5dc7 - rustc_query_impl[b78e7f0549dc02d3]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  56:     0x7f12ea9409fb - rustc_interface[ceb207a8fb5539d]::interface::run_compiler::<core[ed182bbac36ed604]::result::Result<(), rustc_span[a4806a91d128f927]::ErrorGuaranteed>, rustc_driver_impl[f037f419b039420a]::run_compiler::{closure#0}>::{closure#0}
  57:     0x7f12eab6ef12 - std[73253c920228642]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[ceb207a8fb5539d]::util::run_in_thread_with_globals<rustc_interface[ceb207a8fb5539d]::util::run_in_thread_pool_with_globals<rustc_interface[ceb207a8fb5539d]::interface::run_compiler<core[ed182bbac36ed604]::result::Result<(), rustc_span[a4806a91d128f927]::ErrorGuaranteed>, rustc_driver_impl[f037f419b039420a]::run_compiler::{closure#0}>::{closure#0}, core[ed182bbac36ed604]::result::Result<(), rustc_span[a4806a91d128f927]::ErrorGuaranteed>>::{closure#0}, core[ed182bbac36ed604]::result::Result<(), rustc_span[a4806a91d128f927]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[ed182bbac36ed604]::result::Result<(), rustc_span[a4806a91d128f927]::ErrorGuaranteed>>
  58:     0x7f12eab6ed3e - <<std[73253c920228642]::thread::Builder>::spawn_unchecked_<rustc_interface[ceb207a8fb5539d]::util::run_in_thread_with_globals<rustc_interface[ceb207a8fb5539d]::util::run_in_thread_pool_with_globals<rustc_interface[ceb207a8fb5539d]::interface::run_compiler<core[ed182bbac36ed604]::result::Result<(), rustc_span[a4806a91d128f927]::ErrorGuaranteed>, rustc_driver_impl[f037f419b039420a]::run_compiler::{closure#0}>::{closure#0}, core[ed182bbac36ed604]::result::Result<(), rustc_span[a4806a91d128f927]::ErrorGuaranteed>>::{closure#0}, core[ed182bbac36ed604]::result::Result<(), rustc_span[a4806a91d128f927]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[ed182bbac36ed604]::result::Result<(), rustc_span[a4806a91d128f927]::ErrorGuaranteed>>::{closure#1} as core[ed182bbac36ed604]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  59:     0x7f12ebbae985 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h37d86e7af57ec8cf
                               at /rustc/b381d3ab27f788f990551100c4425bb782d26d76/library/alloc/src/boxed.rs:2016:9
  60:     0x7f12ebbae985 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h99a2218ed45ac1ce
                               at /rustc/b381d3ab27f788f990551100c4425bb782d26d76/library/alloc/src/boxed.rs:2016:9
  61:     0x7f12ebbae985 - std::sys::pal::unix::thread::Thread::new::thread_start::h6344e9d30547345d
                               at /rustc/b381d3ab27f788f990551100c4425bb782d26d76/library/std/src/sys/pal/unix/thread.rs:108:17
  62:     0x7f12e5aa09eb - <unknown>
  63:     0x7f12e5b247cc - <unknown>
  64:                0x0 - <unknown>

error: the compiler unexpectedly panicked. this is a bug.

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 1.78.0-nightly (b381d3ab2 2024-02-12) running on x86_64-unknown-linux-gnu

query stack during panic:
#0 [eval_to_allocation_raw] const-evaluating + checking `FORTY_TWO`
#1 [eval_to_const_value_raw] simplifying constant for the type system `FORTY_TWO`
#2 [eval_to_allocation_raw] const-evaluating + checking `main::promoted[1]`
#3 [eval_to_const_value_raw] simplifying constant for the type system `main::promoted[1]`  |  = note: this failure-note originates in the macro `assert_eq` (in Nightly builds, run with -Z macro-backtrace for more info)

#4 [mir_drops_elaborated_and_const_checked] elaborating drops for `main`
#5 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0053`.

[matthiaskrgr]

regressed again in #120550 lol cc @oli-obk