ICE: `unexpected type encountered in variance inference: _`
matthiaskrgr opened this issue · 4 comments
matthiaskrgr commented
Code
pub trait Iter {
type Item<'a> where Self: 'a;
fn next<'a>(&'a mut self) -> Option<Windows<T>>;
fn for_each<F>(&'a mut self, mut f: F)
where Self: Sized, F: for<'a> FnMut(Self::Windows<'a>)
{
todo!()
}
}
pub struct Windows<T> {}
impl<T> Windows<'a> {
type Item<'a> where T: 'a = &'a mut [T];
fn next<'a>(&'a mut self) -> Option<Self::Item<'a>> {
todo!();
}
}
impl<T> Iter for Windows<T> {
fn T<'a>(&'for_each mut self) -> Option<Self::Item<'a>> {
todo!();
}
}
Meta
rustc --version --verbose:
rustc 1.70.0-nightly (7b4f48927 2023-03-12)
binary: rustc
commit-hash: 7b4f48927dce585f747a58083b45ab62b9d73a53
commit-date: 2023-03-12
host: x86_64-unknown-linux-gnu
release: 1.70.0-nightly
LLVM version: 15.0.7
Error output
error[E0261]: use of undeclared lifetime name `'a`
--> 48.rs:6:21
|
6 | fn for_each<F>(&'a mut self, mut f: F)
| ^^ undeclared lifetime
|
help: consider introducing lifetime `'a` here
|
6 | fn for_each<'a, F>(&'a mut self, mut f: F)
| +++
help: consider introducing lifetime `'a` here
|
1 | pub trait Iter<'a> {
| ++++
error[E0261]: use of undeclared lifetime name `'a`
--> 48.rs:15:17
|
15 | impl<T> Windows<'a> {
| - ^^ undeclared lifetime
| |
| help: consider introducing lifetime `'a` here: `'a,`
error[E0407]: method `T` is not a member of trait `Iter`
--> 48.rs:25:5
|
25 | / fn T<'a>(&'for_each mut self) -> Option<Self::Item<'a>> {
26 | | todo!();
27 | | }
| |_____^ not a member of trait `Iter`
error[E0261]: use of undeclared lifetime name `'for_each`
--> 48.rs:25:15
|
25 | fn T<'a>(&'for_each mut self) -> Option<Self::Item<'a>> {
| ^^^^^^^^^ undeclared lifetime
|
help: consider introducing lifetime `'for_each` here
|
25 | fn T<'for_each, 'a>(&'for_each mut self) -> Option<Self::Item<'a>> {
| ++++++++++
help: consider introducing lifetime `'for_each` here
|
23 | impl<'for_each, T> Iter for Windows<T> {
| ++++++++++
error[E0412]: cannot find type `T` in this scope
--> 48.rs:4:49
|
4 | fn next<'a>(&'a mut self) -> Option<Windows<T>>;
| ^ not found in this scope
warning: where clause not allowed here
--> 48.rs:16:19
|
16 | type Item<'a> where T: 'a = &'a mut [T];
| ^^^^^^^^^^^
|
= note: see issue #89122 <https://github.com/rust-lang/rust/issues/89122> for more information
= note: `#[warn(deprecated_where_clause_location)]` on by default
help: move it to the end of the type declaration
|
16 - type Item<'a> where T: 'a = &'a mut [T];
16 + type Item<'a> = &'a mut [T] where T: 'a;
|
error[E0601]: `main` function not found in crate `48`
--> 48.rs:28:2
|
28 | }
| ^ consider adding a `main` function to `48.rs`
error[E0107]: struct takes 0 lifetime arguments but 1 lifetime argument was supplied
--> 48.rs:15:9
|
15 | impl<T> Windows<'a> {
| ^^^^^^^---- help: remove these generics
| |
| expected 0 lifetime arguments
|
note: struct defined here, with 0 lifetime parameters
--> 48.rs:13:12
|
13 | pub struct Windows<T> {}
| ^^^^^^^
error[E0107]: struct takes 1 generic argument but 0 generic arguments were supplied
--> 48.rs:15:9
|
15 | impl<T> Windows<'a> {
| ^^^^^^^ expected 1 generic argument
|
note: struct defined here, with 1 generic parameter: `T`
--> 48.rs:13:12
|
13 | pub struct Windows<T> {}
| ^^^^^^^ -
help: add missing generic argument
|
15 | impl<T> Windows<'a, T> {
| +++
error[E0220]: associated type `Windows` not found for `Self`
--> 48.rs:7:51
|
7 | where Self: Sized, F: for<'a> FnMut(Self::Windows<'a>)
| ^^^^^^^ associated type `Windows` not found
error[E0658]: inherent associated types are unstable
--> 48.rs:16:5
|
16 | type Item<'a> where T: 'a = &'a mut [T];
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: see issue #8995 <https://github.com/rust-lang/rust/issues/8995> for more information
= help: add `#![feature(inherent_associated_types)]` to the crate attributes to enable
Backtrace
error: internal compiler error: compiler/rustc_hir_analysis/src/variance/constraints.rs:301:17: unexpected type encountered in variance inference: _
thread 'rustc' panicked at 'Box<dyn Any>', /rustc/7b4f48927dce585f747a58083b45ab62b9d73a53/compiler/rustc_errors/src/lib.rs:1644:9
stack backtrace:
0: 0x7f8c0716651a - std::backtrace_rs::backtrace::libunwind::trace::hf7d75cca16fd1b61
at /rustc/7b4f48927dce585f747a58083b45ab62b9d73a53/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5
1: 0x7f8c0716651a - std::backtrace_rs::backtrace::trace_unsynchronized::hf5ec95734aab509d
at /rustc/7b4f48927dce585f747a58083b45ab62b9d73a53/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
2: 0x7f8c0716651a - std::sys_common::backtrace::_print_fmt::he95113413355c8cd
at /rustc/7b4f48927dce585f747a58083b45ab62b9d73a53/library/std/src/sys_common/backtrace.rs:65:5
3: 0x7f8c0716651a - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h072d12f2e69ca92b
at /rustc/7b4f48927dce585f747a58083b45ab62b9d73a53/library/std/src/sys_common/backtrace.rs:44:22
4: 0x7f8c071c9c5e - core::fmt::write::h1d23f16415e96af2
at /rustc/7b4f48927dce585f747a58083b45ab62b9d73a53/library/core/src/fmt/mod.rs:1232:17
5: 0x7f8c07159275 - std::io::Write::write_fmt::hcf1e413fde4ffcd5
at /rustc/7b4f48927dce585f747a58083b45ab62b9d73a53/library/std/src/io/mod.rs:1684:15
6: 0x7f8c071662e5 - std::sys_common::backtrace::_print::h6b2b14bedd5177e7
at /rustc/7b4f48927dce585f747a58083b45ab62b9d73a53/library/std/src/sys_common/backtrace.rs:47:5
7: 0x7f8c071662e5 - std::sys_common::backtrace::print::h09ccebfbcd382e89
at /rustc/7b4f48927dce585f747a58083b45ab62b9d73a53/library/std/src/sys_common/backtrace.rs:34:9
8: 0x7f8c0716905f - std::panicking::default_hook::{{closure}}::h4ee055db778febc2
at /rustc/7b4f48927dce585f747a58083b45ab62b9d73a53/library/std/src/panicking.rs:271:22
9: 0x7f8c07168d9b - std::panicking::default_hook::ha74f60e3a15d95fb
at /rustc/7b4f48927dce585f747a58083b45ab62b9d73a53/library/std/src/panicking.rs:290:9
10: 0x7f8c0a497085 - rustc_driver_impl[d355a67661263e47]::DEFAULT_HOOK::{closure#0}::{closure#0}
11: 0x7f8c0716989d - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::h7f34603beb945e8f
at /rustc/7b4f48927dce585f747a58083b45ab62b9d73a53/library/alloc/src/boxed.rs:2002:9
12: 0x7f8c0716989d - std::panicking::rust_panic_with_hook::h4b5d379936d4932f
at /rustc/7b4f48927dce585f747a58083b45ab62b9d73a53/library/std/src/panicking.rs:696:13
13: 0x7f8c0aa02371 - std[e52d7c968ed01318]::panicking::begin_panic::<rustc_errors[45159b7f7e36021d]::ExplicitBug>::{closure#0}
14: 0x7f8c0a9fdaa6 - std[e52d7c968ed01318]::sys_common::backtrace::__rust_end_short_backtrace::<std[e52d7c968ed01318]::panicking::begin_panic<rustc_errors[45159b7f7e36021d]::ExplicitBug>::{closure#0}, !>
15: 0x7f8c0aa86046 - std[e52d7c968ed01318]::panicking::begin_panic::<rustc_errors[45159b7f7e36021d]::ExplicitBug>
16: 0x7f8c0aa51e06 - std[e52d7c968ed01318]::panic::panic_any::<rustc_errors[45159b7f7e36021d]::ExplicitBug>
17: 0x7f8c0aa4d966 - <rustc_errors[45159b7f7e36021d]::HandlerInner>::bug::<&alloc[fc860cae0dfa1ab1]::string::String>
18: 0x7f8c0aa4d630 - <rustc_errors[45159b7f7e36021d]::Handler>::bug::<&alloc[fc860cae0dfa1ab1]::string::String>
19: 0x7f8c0aa39a9b - rustc_middle[a96ac5d591578447]::util::bug::opt_span_bug_fmt::<rustc_span[f8bdfaef83e46314]::span_encoding::Span>::{closure#0}
20: 0x7f8c0aa384fa - rustc_middle[a96ac5d591578447]::ty::context::tls::with_opt::<rustc_middle[a96ac5d591578447]::util::bug::opt_span_bug_fmt<rustc_span[f8bdfaef83e46314]::span_encoding::Span>::{closure#0}, !>::{closure#0}
21: 0x7f8c0aa384c6 - rustc_middle[a96ac5d591578447]::ty::context::tls::with_context_opt::<rustc_middle[a96ac5d591578447]::ty::context::tls::with_opt<rustc_middle[a96ac5d591578447]::util::bug::opt_span_bug_fmt<rustc_span[f8bdfaef83e46314]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
22: 0x7f8c0aa399e6 - rustc_middle[a96ac5d591578447]::util::bug::opt_span_bug_fmt::<rustc_span[f8bdfaef83e46314]::span_encoding::Span>
23: 0x7f8c08ab44b3 - rustc_middle[a96ac5d591578447]::util::bug::bug_fmt
24: 0x7f8c08c3e6bd - <rustc_hir_analysis[357075c2c3fc2a7b]::variance::constraints::ConstraintContext>::add_constraints_from_ty
25: 0x7f8c08c3dc69 - <rustc_hir_analysis[357075c2c3fc2a7b]::variance::constraints::ConstraintContext>::add_constraints_from_ty
26: 0x7f8c08c3d247 - <rustc_hir_analysis[357075c2c3fc2a7b]::variance::constraints::ConstraintContext>::build_constraints_for_item
27: 0x7f8c08c3cc9a - rustc_hir_analysis[357075c2c3fc2a7b]::variance::constraints::add_constraints_from_crate
28: 0x7f8c08c3c123 - rustc_hir_analysis[357075c2c3fc2a7b]::variance::crate_variances
29: 0x7f8c09cbe53b - rustc_query_system[704b80a7bc44cd49]::query::plumbing::try_execute_query::<rustc_query_impl[217bee59c5548bf5]::queries::crate_variances, rustc_query_impl[217bee59c5548bf5]::plumbing::QueryCtxt>
30: 0x7f8c09cbe210 - <rustc_query_impl[217bee59c5548bf5]::Queries as rustc_middle[a96ac5d591578447]::ty::query::QueryEngine>::crate_variances
31: 0x7f8c0945afcc - rustc_hir_analysis[357075c2c3fc2a7b]::variance::variances_of
32: 0x7f8c09458cc8 - rustc_query_system[704b80a7bc44cd49]::query::plumbing::try_execute_query::<rustc_query_impl[217bee59c5548bf5]::queries::variances_of, rustc_query_impl[217bee59c5548bf5]::plumbing::QueryCtxt>
33: 0x7f8c094588bd - <rustc_query_impl[217bee59c5548bf5]::Queries as rustc_middle[a96ac5d591578447]::ty::query::QueryEngine>::variances_of
34: 0x7f8c0850e26c - rustc_middle[a96ac5d591578447]::ty::relate::super_relate_tys::<rustc_infer[8071ebb96624e335]::infer::sub::Sub>
35: 0x7f8c0850a261 - <rustc_infer[8071ebb96624e335]::infer::sub::Sub as rustc_middle[a96ac5d591578447]::ty::relate::TypeRelation>::tys
36: 0x7f8c099e52a3 - <rustc_infer[8071ebb96624e335]::infer::InferCtxt>::commit_if_ok::<rustc_infer[8071ebb96624e335]::infer::InferOk<()>, rustc_middle[a96ac5d591578447]::ty::error::TypeError, <rustc_infer[8071ebb96624e335]::infer::at::Trace>::sub<rustc_middle[a96ac5d591578447]::ty::Ty>::{closure#0}>
37: 0x7f8c099e50d7 - <rustc_trait_selection[8ee7c2d509810bbf]::traits::engine::ObligationCtxt>::sup::<rustc_middle[a96ac5d591578447]::ty::Ty>
38: 0x7f8c0a5c340a - <rustc_infer[8071ebb96624e335]::infer::InferCtxt>::probe::<core[125d846441ac421f]::option::Option<(rustc_span[f8bdfaef83e46314]::def_id::DefId, rustc_span[f8bdfaef83e46314]::def_id::DefId, &rustc_middle[a96ac5d591578447]::ty::list::List<rustc_middle[a96ac5d591578447]::ty::subst::GenericArg>)>, <dyn rustc_hir_analysis[357075c2c3fc2a7b]::astconv::AstConv>::lookup_inherent_assoc_ty::{closure#1}::{closure#0}>
39: 0x7f8c0a5bfba6 - <&mut <dyn rustc_hir_analysis[357075c2c3fc2a7b]::astconv::AstConv>::lookup_inherent_assoc_ty::{closure#1} as core[125d846441ac421f]::ops::function::FnMut<(&(rustc_span[f8bdfaef83e46314]::def_id::DefId, (rustc_span[f8bdfaef83e46314]::def_id::DefId, rustc_span[f8bdfaef83e46314]::def_id::DefId)),)>>::call_mut
40: 0x7f8c0a605bee - <alloc[fc860cae0dfa1ab1]::vec::Vec<(rustc_span[f8bdfaef83e46314]::def_id::DefId, rustc_span[f8bdfaef83e46314]::def_id::DefId, &rustc_middle[a96ac5d591578447]::ty::list::List<rustc_middle[a96ac5d591578447]::ty::subst::GenericArg>)> as alloc[fc860cae0dfa1ab1]::vec::spec_from_iter::SpecFromIter<(rustc_span[f8bdfaef83e46314]::def_id::DefId, rustc_span[f8bdfaef83e46314]::def_id::DefId, &rustc_middle[a96ac5d591578447]::ty::list::List<rustc_middle[a96ac5d591578447]::ty::subst::GenericArg>), core[125d846441ac421f]::iter::adapters::filter_map::FilterMap<core[125d846441ac421f]::slice::iter::Iter<(rustc_span[f8bdfaef83e46314]::def_id::DefId, (rustc_span[f8bdfaef83e46314]::def_id::DefId, rustc_span[f8bdfaef83e46314]::def_id::DefId))>, <dyn rustc_hir_analysis[357075c2c3fc2a7b]::astconv::AstConv>::lookup_inherent_assoc_ty::{closure#1}>>>::from_iter
41: 0x7f8c09312a66 - <dyn rustc_hir_analysis[357075c2c3fc2a7b]::astconv::AstConv>::associated_path_to_ty::{closure#0}
42: 0x7f8c092f75a6 - <dyn rustc_hir_analysis[357075c2c3fc2a7b]::astconv::AstConv>::ast_ty_to_ty_inner::{closure#0}
43: 0x7f8c092fb21c - <dyn rustc_hir_analysis[357075c2c3fc2a7b]::astconv::AstConv>::res_to_ty
44: 0x7f8c092f725e - <dyn rustc_hir_analysis[357075c2c3fc2a7b]::astconv::AstConv>::ast_ty_to_ty_inner::{closure#0}
45: 0x7f8c09390a3b - <dyn rustc_hir_analysis[357075c2c3fc2a7b]::astconv::AstConv>::ty_of_fn::{closure#0}
46: 0x7f8c09402d35 - rustc_hir_analysis[357075c2c3fc2a7b]::collect::fn_sig
47: 0x7f8c09401140 - rustc_query_system[704b80a7bc44cd49]::query::plumbing::try_execute_query::<rustc_query_impl[217bee59c5548bf5]::queries::fn_sig, rustc_query_impl[217bee59c5548bf5]::plumbing::QueryCtxt>
48: 0x7f8c08c805a1 - <rustc_hir_analysis[357075c2c3fc2a7b]::collect::CollectItemTypesVisitor as rustc_hir[4aa57babd8685147]::intravisit::Visitor>::visit_impl_item
49: 0x7f8c08c7aa41 - <rustc_middle[a96ac5d591578447]::hir::map::Map>::visit_item_likes_in_module::<rustc_hir_analysis[357075c2c3fc2a7b]::collect::CollectItemTypesVisitor>
50: 0x7f8c08c7a84c - rustc_hir_analysis[357075c2c3fc2a7b]::collect::collect_mod_item_types
51: 0x7f8c09ac706e - rustc_query_system[704b80a7bc44cd49]::query::plumbing::try_execute_query::<rustc_query_impl[217bee59c5548bf5]::queries::collect_mod_item_types, rustc_query_impl[217bee59c5548bf5]::plumbing::QueryCtxt>
52: 0x7f8c09ac6bf3 - <rustc_query_impl[217bee59c5548bf5]::Queries as rustc_middle[a96ac5d591578447]::ty::query::QueryEngine>::collect_mod_item_types
53: 0x7f8c087b0363 - <rustc_session[7e23441c2db8ce4a]::session::Session>::track_errors::<rustc_hir_analysis[357075c2c3fc2a7b]::check_crate::{closure#0}, ()>
54: 0x7f8c087acce2 - rustc_hir_analysis[357075c2c3fc2a7b]::check_crate
55: 0x7f8c087a2d12 - rustc_interface[6bf42eb308c32713]::passes::analysis
56: 0x7f8c09cab71c - rustc_query_system[704b80a7bc44cd49]::query::plumbing::try_execute_query::<rustc_query_impl[217bee59c5548bf5]::queries::analysis, rustc_query_impl[217bee59c5548bf5]::plumbing::QueryCtxt>
57: 0x7f8c09cab410 - <rustc_query_impl[217bee59c5548bf5]::Queries as rustc_middle[a96ac5d591578447]::ty::query::QueryEngine>::analysis
58: 0x7f8c09ad02f9 - <rustc_middle[a96ac5d591578447]::ty::context::GlobalCtxt>::enter::<rustc_driver_impl[d355a67661263e47]::run_compiler::{closure#1}::{closure#2}::{closure#4}, core[125d846441ac421f]::result::Result<(), rustc_span[f8bdfaef83e46314]::ErrorGuaranteed>>
59: 0x7f8c096c8498 - rustc_span[f8bdfaef83e46314]::with_source_map::<core[125d846441ac421f]::result::Result<(), rustc_span[f8bdfaef83e46314]::ErrorGuaranteed>, rustc_interface[6bf42eb308c32713]::interface::run_compiler<core[125d846441ac421f]::result::Result<(), rustc_span[f8bdfaef83e46314]::ErrorGuaranteed>, rustc_driver_impl[d355a67661263e47]::run_compiler::{closure#1}>::{closure#0}::{closure#0}>
60: 0x7f8c096bf70c - std[e52d7c968ed01318]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[6bf42eb308c32713]::util::run_in_thread_pool_with_globals<rustc_interface[6bf42eb308c32713]::interface::run_compiler<core[125d846441ac421f]::result::Result<(), rustc_span[f8bdfaef83e46314]::ErrorGuaranteed>, rustc_driver_impl[d355a67661263e47]::run_compiler::{closure#1}>::{closure#0}, core[125d846441ac421f]::result::Result<(), rustc_span[f8bdfaef83e46314]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[125d846441ac421f]::result::Result<(), rustc_span[f8bdfaef83e46314]::ErrorGuaranteed>>
61: 0x7f8c096bf13a - <<std[e52d7c968ed01318]::thread::Builder>::spawn_unchecked_<rustc_interface[6bf42eb308c32713]::util::run_in_thread_pool_with_globals<rustc_interface[6bf42eb308c32713]::interface::run_compiler<core[125d846441ac421f]::result::Result<(), rustc_span[f8bdfaef83e46314]::ErrorGuaranteed>, rustc_driver_impl[d355a67661263e47]::run_compiler::{closure#1}>::{closure#0}, core[125d846441ac421f]::result::Result<(), rustc_span[f8bdfaef83e46314]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[125d846441ac421f]::result::Result<(), rustc_span[f8bdfaef83e46314]::ErrorGuaranteed>>::{closure#1} as core[125d846441ac421f]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
62: 0x7f8c07173793 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::hc0a50816e1eb2bba
at /rustc/7b4f48927dce585f747a58083b45ab62b9d73a53/library/alloc/src/boxed.rs:1988:9
63: 0x7f8c07173793 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::hb2f83fc2049033c3
at /rustc/7b4f48927dce585f747a58083b45ab62b9d73a53/library/alloc/src/boxed.rs:1988:9
64: 0x7f8c07173793 - std::sys::unix::thread::Thread::new::thread_start::hce5861512f8bf7ea
at /rustc/7b4f48927dce585f747a58083b45ab62b9d73a53/library/std/src/sys/unix/thread.rs:108:17
65: 0x7f8c06f05bb5 - <unknown>
66: 0x7f8c06f87d90 - <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 1.70.0-nightly (7b4f48927 2023-03-12) running on x86_64-unknown-linux-gnu
query stack during panic:
#0 [crate_variances] computing the variances for items in this crate
#1 [variances_of] computing the variances of `Windows`
#2 [fn_sig] computing function signature of `<impl at 48.rs:23:1: 23:28>::T`
#3 [collect_mod_item_types] collecting item types in top-level module
#4 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to 11 previous errors; 1 warning emitted
Some errors have detailed explanations: E0107, E0220, E0261, E0407, E0412, E0601, E0658.
For more information about an error, try `rustc --explain E0107`.
langston-barrett commented
Minimized with treereduce:
struct Windows<T> {}
impl<T> Windows {
type Item = &[T];
fn next() -> Option<Self::Item> {}
}
impl<T> Windows<T> {
fn T() -> Option<Self::Item> {}
}@rustbot label +S-bug-has-mcve
matthiaskrgr commented
bwmf2 commented
Alternative:
#![allow(incomplete_features)]
#![feature(inherent_associated_types)]
struct Windows<T> {}
impl<T> Windows<()> {
type Item = T;
fn next() -> Self::Item {}
}
impl<T> Windows<T> {
fn gates() -> Self::Item {}
}Would the error change if the compiler is built with debug = true?