Closed
Description
the saga continues!
auto-reduced (treereduce-rust):
trait Foo {
fn test() -> impl Foo(u32) -> u32 {}
}original:
trait Foo {
fn test() -> impl Foo(u32) -> u32 {
|| x.count_ones()
}
}Version information
rustc 1.88.0-nightly (78f2104e3 2025-04-16)
binary: rustc
commit-hash: 78f2104e334068d5a892a170d50193c0025c690e
commit-date: 2025-04-16
host: x86_64-unknown-linux-gnu
release: 1.88.0-nightly
LLVM version: 20.1.2
Possibly related line of code:
rust/compiler/rustc_middle/src/ty/assoc.rs
Lines 37 to 49 in 78f2104
Command:
/home/matthias/.rustup/toolchains/master/bin/rustc
Program output
error[E0601]: `main` function not found in crate `mvce`
--> /tmp/icemaker_global_tempdir.JNaW56ApoC9W/rustc_testrunner_tmpdir_reporting.WdMzLCnsDMQF/mvce.rs:3:2
|
3 | }
| ^ consider adding a `main` function to `/tmp/icemaker_global_tempdir.JNaW56ApoC9W/rustc_testrunner_tmpdir_reporting.WdMzLCnsDMQF/mvce.rs`
error[E0658]: parenthetical notation is only stable when used with `Fn`-family traits
--> /tmp/icemaker_global_tempdir.JNaW56ApoC9W/rustc_testrunner_tmpdir_reporting.WdMzLCnsDMQF/mvce.rs:2:23
|
2 | fn test() -> impl Foo(u32) -> u32 {}
| ^^^^^^^^^^^^^^^
|
= note: see issue #29625 <https://github.com/rust-lang/rust/issues/29625> for more information
= help: add `#![feature(unboxed_closures)]` to the crate attributes to enable
= note: this compiler was built on 2025-04-16; consider upgrading it if it is out of date
thread 'rustc' panicked at compiler/rustc_middle/src/ty/assoc.rs:43:25:
name of non-Rpitit assoc item
stack backtrace:
0: 0x7d0bb86e87b3 - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::hbe9a35f36773aa35
1: 0x7d0bb8e05b07 - core::fmt::write::hc5bf8d0f3fe78c0c
2: 0x7d0bba2a6011 - std::io::Write::write_fmt::ha84e19e9665c5650
3: 0x7d0bb86e8612 - std::sys::backtrace::BacktraceLock::print::h8bb069e50731329e
4: 0x7d0bb86ebf8a - std::panicking::default_hook::{{closure}}::h9d41ab1a4babb09c
5: 0x7d0bb86ebb0f - std::panicking::default_hook::h6eac92de6962e409
6: 0x7d0bb775a5b3 - std[2ad6d0fee2e09edc]::panicking::update_hook::<alloc[9d3eded591b7d627]::boxed::Box<rustc_driver_impl[5fbee50f607e217]::install_ice_hook::{closure#1}>>::{closure#0}
7: 0x7d0bb86ec803 - std::panicking::rust_panic_with_hook::hfe63a727073f604a
8: 0x7d0bb86ec4fa - std::panicking::begin_panic_handler::{{closure}}::h92b47807861c6a3c
9: 0x7d0bb86e8c89 - std::sys::backtrace::__rust_end_short_backtrace::hb9f6a948a925f382
10: 0x7d0bb86ec1bd - __rustc[9e5fbd37ce37ba6c]::rust_begin_unwind
11: 0x7d0bb508d1c0 - core::panicking::panic_fmt::hcb046f91e9c65441
12: 0x7d0bb6393fab - core::option::expect_failed::hb997976540264db6
13: 0x7d0bb78de395 - <core[58638a26b282635c]::iter::adapters::map::Map<core[58638a26b282635c]::iter::adapters::filter::Filter<core[58638a26b282635c]::iter::adapters::filter::Filter<core[58638a26b282635c]::iter::adapters::filter::Filter<core[58638a26b282635c]::iter::adapters::map::Map<core[58638a26b282635c]::iter::adapters::map::Map<core[58638a26b282635c]::slice::iter::Iter<(core[58638a26b282635c]::option::Option<rustc_span[85c7266a28769ec9]::symbol::Symbol>, rustc_middle[9902b4682aa0495d]::ty::assoc::AssocItem)>, <rustc_data_structures[2fd0664b6811e02d]::sorted_map::index_map::SortedIndexMultiMap<u32, core[58638a26b282635c]::option::Option<rustc_span[85c7266a28769ec9]::symbol::Symbol>, rustc_middle[9902b4682aa0495d]::ty::assoc::AssocItem>>::iter::{closure#0}>, <rustc_middle[9902b4682aa0495d]::ty::assoc::AssocItems>::in_definition_order::{closure#0}>, <rustc_hir_analysis[97d869527a21e1a5]::errors::wrong_number_of_generic_args::WrongNumberOfGenericArgs>::get_unbound_associated_types::{closure#0}>, <rustc_hir_analysis[97d869527a21e1a5]::errors::wrong_number_of_generic_args::WrongNumberOfGenericArgs>::get_unbound_associated_types::{closure#1}>, <rustc_hir_analysis[97d869527a21e1a5]::errors::wrong_number_of_generic_args::WrongNumberOfGenericArgs>::get_unbound_associated_types::{closure#2}>, <rustc_hir_analysis[97d869527a21e1a5]::errors::wrong_number_of_generic_args::WrongNumberOfGenericArgs>::get_unbound_associated_types::{closure#3}> as core[58638a26b282635c]::iter::traits::iterator::Iterator>::next
14: 0x7d0bb793efd7 - <rustc_hir_analysis[97d869527a21e1a5]::errors::wrong_number_of_generic_args::WrongNumberOfGenericArgs>::get_unbound_associated_types
15: 0x7d0bb7942be7 - <rustc_hir_analysis[97d869527a21e1a5]::errors::wrong_number_of_generic_args::WrongNumberOfGenericArgs as rustc_errors[fd960650b33fb9c4]::diagnostic::Diagnostic>::into_diag
16: 0x7d0bb90e431b - <dyn rustc_hir_analysis[97d869527a21e1a5]::hir_ty_lowering::HirTyLowerer>::lower_generic_args_of_path::{closure#0}
17: 0x7d0bb90dd639 - <dyn rustc_hir_analysis[97d869527a21e1a5]::hir_ty_lowering::HirTyLowerer>::lower_poly_trait_ref
18: 0x7d0bb90dcba4 - <dyn rustc_hir_analysis[97d869527a21e1a5]::hir_ty_lowering::HirTyLowerer>::lower_bounds::<&[rustc_hir[603e0a66c7ecd982]::hir::GenericBound]>
19: 0x7d0bb9a40d61 - rustc_hir_analysis[97d869527a21e1a5]::collect::item_bounds::associated_type_bounds
20: 0x7d0bb9a403d4 - rustc_hir_analysis[97d869527a21e1a5]::collect::item_bounds::explicit_item_bounds
21: 0x7d0bb9a403a7 - rustc_query_impl[2236df548ee42a79]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[2236df548ee42a79]::query_impl::explicit_item_bounds::dynamic_query::{closure#2}::{closure#0}, rustc_middle[9902b4682aa0495d]::query::erase::Erased<[u8; 16usize]>>
22: 0x7d0bb9a4036b - <rustc_query_impl[2236df548ee42a79]::query_impl::explicit_item_bounds::dynamic_query::{closure#2} as core[58638a26b282635c]::ops::function::FnOnce<(rustc_middle[9902b4682aa0495d]::ty::context::TyCtxt, rustc_span[85c7266a28769ec9]::def_id::DefId)>>::call_once
23: 0x7d0bb9001f10 - rustc_query_system[be2b43304ba7dfb]::query::plumbing::try_execute_query::<rustc_query_impl[2236df548ee42a79]::DynamicConfig<rustc_query_system[be2b43304ba7dfb]::query::caches::DefIdCache<rustc_middle[9902b4682aa0495d]::query::erase::Erased<[u8; 16usize]>>, false, false, false>, rustc_query_impl[2236df548ee42a79]::plumbing::QueryCtxt, false>
24: 0x7d0bb98ddea0 - rustc_query_impl[2236df548ee42a79]::query_impl::explicit_item_bounds::get_query_non_incr::__rust_end_short_backtrace
25: 0x7d0bb9573008 - rustc_hir_analysis[97d869527a21e1a5]::check::compare_impl_item::check_type_bounds
26: 0x7d0bb9650c98 - rustc_hir_analysis[97d869527a21e1a5]::check::check::check_item_type
27: 0x7d0bb95f931a - rustc_hir_analysis[97d869527a21e1a5]::check::wfcheck::check_well_formed
28: 0x7d0bb95f78eb - rustc_query_impl[2236df548ee42a79]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[2236df548ee42a79]::query_impl::check_well_formed::dynamic_query::{closure#2}::{closure#0}, rustc_middle[9902b4682aa0495d]::query::erase::Erased<[u8; 1usize]>>
29: 0x7d0bb95f7194 - rustc_query_system[be2b43304ba7dfb]::query::plumbing::try_execute_query::<rustc_query_impl[2236df548ee42a79]::DynamicConfig<rustc_data_structures[2fd0664b6811e02d]::vec_cache::VecCache<rustc_span[85c7266a28769ec9]::def_id::LocalDefId, rustc_middle[9902b4682aa0495d]::query::erase::Erased<[u8; 1usize]>, rustc_query_system[be2b43304ba7dfb]::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl[2236df548ee42a79]::plumbing::QueryCtxt, false>
30: 0x7d0bb95f6c83 - rustc_query_impl[2236df548ee42a79]::query_impl::check_well_formed::get_query_non_incr::__rust_end_short_backtrace
31: 0x7d0bb95f30e5 - rustc_hir_analysis[97d869527a21e1a5]::check::wfcheck::check_mod_type_wf
32: 0x7d0bb95f2edd - rustc_query_impl[2236df548ee42a79]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[2236df548ee42a79]::query_impl::check_mod_type_wf::dynamic_query::{closure#2}::{closure#0}, rustc_middle[9902b4682aa0495d]::query::erase::Erased<[u8; 1usize]>>
33: 0x7d0bb9991999 - rustc_query_system[be2b43304ba7dfb]::query::plumbing::try_execute_query::<rustc_query_impl[2236df548ee42a79]::DynamicConfig<rustc_query_system[be2b43304ba7dfb]::query::caches::DefaultCache<rustc_span[85c7266a28769ec9]::def_id::LocalModDefId, rustc_middle[9902b4682aa0495d]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[2236df548ee42a79]::plumbing::QueryCtxt, false>
34: 0x7d0bb9991710 - rustc_query_impl[2236df548ee42a79]::query_impl::check_mod_type_wf::get_query_non_incr::__rust_end_short_backtrace
35: 0x7d0bb903ffe6 - rustc_hir_analysis[97d869527a21e1a5]::check_crate
36: 0x7d0bb91d46f2 - rustc_interface[8c35278d6665784]::passes::run_required_analyses
37: 0x7d0bb99a0dde - rustc_interface[8c35278d6665784]::passes::analysis
38: 0x7d0bb99a0dad - rustc_query_impl[2236df548ee42a79]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[2236df548ee42a79]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[9902b4682aa0495d]::query::erase::Erased<[u8; 0usize]>>
39: 0x7d0bb9e141bd - rustc_query_system[be2b43304ba7dfb]::query::plumbing::try_execute_query::<rustc_query_impl[2236df548ee42a79]::DynamicConfig<rustc_query_system[be2b43304ba7dfb]::query::caches::SingleCache<rustc_middle[9902b4682aa0495d]::query::erase::Erased<[u8; 0usize]>>, false, false, false>, rustc_query_impl[2236df548ee42a79]::plumbing::QueryCtxt, false>
40: 0x7d0bb9e13eb8 - rustc_query_impl[2236df548ee42a79]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
41: 0x7d0bb9cd223e - rustc_interface[8c35278d6665784]::passes::create_and_enter_global_ctxt::<core[58638a26b282635c]::option::Option<rustc_interface[8c35278d6665784]::queries::Linker>, rustc_driver_impl[5fbee50f607e217]::run_compiler::{closure#0}::{closure#2}>::{closure#2}::{closure#0}
42: 0x7d0bb9f0acc4 - rustc_interface[8c35278d6665784]::interface::run_compiler::<(), rustc_driver_impl[5fbee50f607e217]::run_compiler::{closure#0}>::{closure#1}
43: 0x7d0bb9cf36e8 - std[2ad6d0fee2e09edc]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[8c35278d6665784]::util::run_in_thread_with_globals<rustc_interface[8c35278d6665784]::util::run_in_thread_pool_with_globals<rustc_interface[8c35278d6665784]::interface::run_compiler<(), rustc_driver_impl[5fbee50f607e217]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
44: 0x7d0bb9cf3ff4 - <<std[2ad6d0fee2e09edc]::thread::Builder>::spawn_unchecked_<rustc_interface[8c35278d6665784]::util::run_in_thread_with_globals<rustc_interface[8c35278d6665784]::util::run_in_thread_pool_with_globals<rustc_interface[8c35278d6665784]::interface::run_compiler<(), rustc_driver_impl[5fbee50f607e217]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core[58638a26b282635c]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
45: 0x7d0bb9cf53f7 - std::sys::pal::unix::thread::Thread::new::thread_start::h7f6705cc982c7917
46: 0x7d0bb3ca370a - <unknown>
47: 0x7d0bb3d27aac - <unknown>
48: 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: please make sure that you have updated to the latest nightly
note: rustc 1.88.0-nightly (78f2104e3 2025-04-16) running on x86_64-unknown-linux-gnu
query stack during panic:
#0 [explicit_item_bounds] finding item bounds for `Foo::{anon_assoc#0}`
#1 [check_well_formed] checking that `Foo` is well-formed
#2 [check_mod_type_wf] checking that types are well-formed in top-level module
#3 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to 2 previous errors
Some errors have detailed explanations: E0601, E0658.
For more information about an error, try `rustc --explain E0601`.