Open
Description
The code is generated by a fuzzer and reduced manually
Possibly a duplicate of #140303
Code
#![feature(type_alias_impl_trait)]
use std::hint::black_box;
trait Func {
type Ret: Id;
}
trait Id {
type Assoc;
}
impl Id for u32 {
type Assoc = u32;
}
impl Id for i32 {
type Assoc = i32;
}
impl<F: FnOnce() -> R, R: Id> Func for F {
type Ret = R;
}
fn bar() -> MyIter {
032
}
type MyIter = impl Copy + Id;
struct Foo<T: Func> {
_func: T,
value: Option<<<T as Func>::Ret as Id>::Assoc>,
}
fn main() {
let mut fn_def = black_box(Foo {
_func: bar,
value: None,
});
}Meta
rustc --version --verbose:
rustc 1.89.0-nightly (5526a2f47 2025-06-20)
binary: rustc
commit-hash: 5526a2f47cd676ceeedc08cf71ae75ce2e9284ae
commit-date: 2025-06-20
host: x86_64-pc-windows-msvc
release: 1.89.0-nightly
LLVM version: 20.1.7
Error output
error: unconstrained opaque type
--> .\test.rs:21:15
|
21 | type MyIter = impl Copy + Id;
| ^^^^^^^^^^^^^^
|
= note: `MyIter` must be used in combination with a concrete type within the same crate
error[E0308]: mismatched types
--> .\test.rs:19:5
|
18 | fn bar() -> MyIter {
| ------ expected `MyIter` because of return type
19 | 032
| ^^^ expected opaque type, found integer
20 | }
21 | type MyIter = impl Copy + Id;
| -------------- the expected opaque type
|
= note: expected opaque type `MyIter`
found type `{integer}`
note: this item must have a `#[define_opaque(MyIter)]` attribute to be able to define hidden types
--> .\test.rs:18:4
|
18 | fn bar() -> MyIter {
| ^^^
error: internal compiler error: compiler\rustc_middle\src\ty\normalize_erasing_regions.rs:171:13: Failed to
normalize std::option::Option<Alias(Projection, AliasTy { args: [Alias(Projection, AliasTy { args: [FnDef(DefId(0:16 ~
test[1c23]::bar), [])], def_id: DefId(0:5 ~ test[1c23]::Func::Ret), .. })], def_id: DefId(0:7 ~ test[1c23]::Id::Assoc), .. })> in
typing_env=TypingEnv { typing_mode: PostAnalysis, param_env: ParamEnv { caller_bounds: [] } }, maybe try to call
`try_normalize_erasing_regions` instead
Backtrace
thread 'rustc' panicked at compiler\rustc_middle\src\ty\normalize_erasing_regions.rs:171:13:
Box<dyn Any>
stack backtrace:
0: 0x7ffa956a5cc2 - std::backtrace_rs::backtrace::win64::trace
at /rustc/5526a2f47cd676ceeedc08cf71ae75ce2e9284ae/library\std\src\..\..\backtrace\src\backtrace\win64.rs:85
1: 0x7ffa956a5cc2 - std::backtrace_rs::backtrace::trace_unsynchronized
at /rustc/5526a2f47cd676ceeedc08cf71ae75ce2e9284ae/library\std\src\..\..\backtrace\src\backtrace\mod.rs:66
2: 0x7ffa956a5cc2 - std::sys::backtrace::_print_fmt
at /rustc/5526a2f47cd676ceeedc08cf71ae75ce2e9284ae/library\std\src\sys\backtrace.rs:66
3: 0x7ffa956a5cc2 - std::sys::backtrace::impl$0::print::impl$0::fmt
at /rustc/5526a2f47cd676ceeedc08cf71ae75ce2e9284ae/library\std\src\sys\backtrace.rs:39
4: 0x7ffa956d89db - core::fmt::rt::Argument::fmt
at /rustc/5526a2f47cd676ceeedc08cf71ae75ce2e9284ae/library\core\src\fmt\rt.rs:173
5: 0x7ffa956d89db - core::fmt::write
at /rustc/5526a2f47cd676ceeedc08cf71ae75ce2e9284ae/library\core\src\fmt\mod.rs:1460
6: 0x7ffa9569ba27 - std::io::default_write_fmt
at /rustc/5526a2f47cd676ceeedc08cf71ae75ce2e9284ae/library\std\src\io\mod.rs:639
7: 0x7ffa9569ba27 - std::io::Write::write_fmt<std::sys::stdio::windows::Stderr>
at /rustc/5526a2f47cd676ceeedc08cf71ae75ce2e9284ae/library\std\src\io\mod.rs:1954
8: 0x7ffa956a5b05 - std::sys::backtrace::BacktraceLock::print
at /rustc/5526a2f47cd676ceeedc08cf71ae75ce2e9284ae/library\std\src\sys\backtrace.rs:42
9: 0x7ffa956ab80a - std::panicking::default_hook::closure$0
at /rustc/5526a2f47cd676ceeedc08cf71ae75ce2e9284ae/library\std\src\panicking.rs:300
10: 0x7ffa956ab5a0 - std::panicking::default_hook
at /rustc/5526a2f47cd676ceeedc08cf71ae75ce2e9284ae/library\std\src\panicking.rs:327
11: 0x7ffa96e5af95 - core[ea54fb714d0d9ca7]::slice::sort::unstable::heapsort::heapsort::<((rustc_lint_defs[745e8a0447f460db]::Level, &str), usize), <((rustc_lint_defs[745e8a0447f460db]::Level, &str), usize) as core[ea54fb714d0d9ca7]::cmp::PartialOrd>::lt>
12: 0x7ffa956ac45c - std::panicking::rust_panic_with_hook
at /rustc/5526a2f47cd676ceeedc08cf71ae75ce2e9284ae/library\std\src\panicking.rs:841
13: 0x7ffa9862a5b3 - RINvNtNtNtNtCsk7lixFzhFdj_4core5slice4sort6stable9quicksort9quicksortTjRNtNtCsc5729v0axqf_12rustc_errors7snippet10AnnotationENCINvMNtCs8twqms2kZVh_5alloc5sliceSB15_11sort_by_keyTINtNtBa_3cmp7ReversejEbENCNCNvMs5_NtB1c_7emitterNtB3o_12HumanEmitter18render_s
14: 0x7ffa9861e699 - std[fdcb23eab682426c]::sys::backtrace::__rust_end_short_backtrace::<std[fdcb23eab682426c]::panicking::begin_panic<rustc_errors[8cbb6869231859f1]::ExplicitBug>::{closure#0}, !>
15: 0x7ffa9861e581 - std[fdcb23eab682426c]::panicking::begin_panic::<rustc_errors[8cbb6869231859f1]::ExplicitBug>
16: 0x7ffa98637045 - <rustc_errors[8cbb6869231859f1]::diagnostic::BugAbort as rustc_errors[8cbb6869231859f1]::diagnostic::EmissionGuarantee>::emit_producing_guarantee
17: 0x7ffa98580379 - rustc_middle[46c07d95ef3dd2bb]::util::bug::span_bug_fmt::<rustc_span[f25b9a1d3de582b9]::span_encoding::Span>
18: 0x7ffa985576fd - <rustc_middle[46c07d95ef3dd2bb]::ty::consts::Const>::walk
19: 0x7ffa985574c6 - <rustc_middle[46c07d95ef3dd2bb]::ty::consts::Const>::walk
20: 0x7ffa98580272 - rustc_middle[46c07d95ef3dd2bb]::util::bug::bug_fmt
21: 0x7ffa96cba4be - <rustc_middle[46c07d95ef3dd2bb]::ty::normalize_erasing_regions::NormalizeAfterErasingRegionsFolder as rustc_type_ir[b5d858062a50f1e5]::fold::TypeFolder<rustc_middle[46c07d95ef3dd2bb]::ty::context::TyCtxt>>::fold_ty
22: 0x7ffa95cb83f5 - <rustc_mir_transform[b4353750b5cbd299]::validate::Validator as rustc_mir_transform[b4353750b5cbd299]::pass_manager::MirPass>::run_pass
23: 0x7ffa95cae903 - <rustc_mir_transform[b4353750b5cbd299]::validate::Validator as rustc_mir_transform[b4353750b5cbd299]::pass_manager::MirPass>::run_pass
24: 0x7ffa974c4df7 - <rustc_mir_transform[b4353750b5cbd299]::post_drop_elaboration::CheckLiveDrops as rustc_mir_transform[b4353750b5cbd299]::pass_manager::MirLint>::run_lint
25: 0x7ffa95be18fe - rustc_mir_transform[b4353750b5cbd299]::run_analysis_to_runtime_passes
26: 0x7ffa95bdc2e1 - rustc_mir_transform[b4353750b5cbd299]::mir_drops_elaborated_and_const_checked
27: 0x7ffa965e8b2b - rustc_query_impl[d8aa46a2dbba62c8]::plumbing::query_key_hash_verify_all
28: 0x7ffa9652f2ae - RINvNtNtCskoNuHGR6BxK_18rustc_query_system5query8plumbing17try_execute_queryINtCsiBiOuvHcJFQ_16rustc_query_impl13DynamicConfigINtNtCsgz2Qsm2zsYx_21rustc_data_structures9vec_cache8VecCacheNtNtCskO41P7xScQL_10rustc_span6def_id10LocalDefIdINtNtNtCs64BRSp7mVxT
29: 0x7ffa965ec412 - rustc_query_impl[d8aa46a2dbba62c8]::plumbing::query_key_hash_verify_all
30: 0x7ffa95714b48 - rustc_interface[43d1a295db27a373]::passes::analysis
31: 0x7ffa952572fa - <alloc[62ba2eed246bf855]::raw_vec::RawVec<rustc_errors[8cbb6869231859f1]::SubstitutionHighlight>>::grow_one
32: 0x7ffa9515cf9a - RINvNtNtCskoNuHGR6BxK_18rustc_query_system5query8plumbing17try_execute_queryINtCsiBiOuvHcJFQ_16rustc_query_impl13DynamicConfigINtNtB4_6caches11SingleCacheINtNtNtCs64BRSp7mVxT_12rustc_middle5query5erase6ErasedAhj0_EEKb0_KB3s_KB3s_ENtNtB1f_8plumbing9QueryCtx
33: 0x7ffa9525d6f3 - rustc_query_impl[d8aa46a2dbba62c8]::query_system
34: 0x7ffa91ba8440 - std[fdcb23eab682426c]::sys::backtrace::__rust_begin_short_backtrace::<<std[fdcb23eab682426c]::thread::Builder>::spawn_unchecked_<ctrlc[9cb8e1be167e9585]::set_handler_inner<rustc_driver_impl[6221a2fc7aac45a2]::install_ctrlc_handler::{closure#0}>::{closure#0}, ()>::{closure#1}::{closure#0}::{closure#0}, ()>
35: 0x7ffa91ba2aa6 - std[fdcb23eab682426c]::sys::backtrace::__rust_begin_short_backtrace::<<std[fdcb23eab682426c]::thread::Builder>::spawn_unchecked_<ctrlc[9cb8e1be167e9585]::set_handler_inner<rustc_driver_impl[6221a2fc7aac45a2]::install_ctrlc_handler::{closure#0}>::{closure#0}, ()>::{closure#1}::{closure#0}::{closure#0}, ()>
36: 0x7ffa91b9eb7f - RINvNtNtCslMW5zL9tQPU_3std3sys9backtrace28___rust_begin_short_backtraceNCNCINvNtCs5OZTDuE54qZ_15rustc_interface4util26run_in_thread_with_globalsNCINvB1e_31run_in_thread_pool_with_globalsNCINvNtB1g_9interface12run_compileruNCNvCs8qlLDMR7YdO_17rustc_driver_i
37: 0x7ffa91bac7bd - std[fdcb23eab682426c]::sys::backtrace::__rust_begin_short_backtrace::<<std[fdcb23eab682426c]::thread::Builder>::spawn_unchecked_<ctrlc[9cb8e1be167e9585]::set_handler_inner<rustc_driver_impl[6221a2fc7aac45a2]::install_ctrlc_handler::{closure#0}>::{closure#0}, ()>::{closure#1}::{closure#0}::{closure#0}, ()>
38: 0x7ffa956b002d - alloc::boxed::impl$28::call_once
at /rustc/5526a2f47cd676ceeedc08cf71ae75ce2e9284ae/library\alloc\src\boxed.rs:1966
39: 0x7ffa956b002d - alloc::boxed::impl$28::call_once
at /rustc/5526a2f47cd676ceeedc08cf71ae75ce2e9284ae/library\alloc\src\boxed.rs:1966
40: 0x7ffa956b002d - std::sys::pal::windows::thread::impl$0::new::thread_start
at /rustc/5526a2f47cd676ceeedc08cf71ae75ce2e9284ae/library\std\src\sys\pal\windows\thread.rs:56
41: 0x7ffaf3447374 - BaseThreadInitThunk
42: 0x7ffaf503cc91 - RtlUserThreadStart
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: -Z validate-mir
query stack during panic:
#0 [mir_drops_elaborated_and_const_checked] elaborating drops for `main`
#1 [analysis] running analysis passes on this crate
end of query stack