ICE: Creating trait object of wrapper struct of a async closure with non-generic arugment and generic arguments with multiple allowed arities #147719
Description
Code
use std::marker::PhantomData; struct RuntimeContext {} pub trait NodeImpl {} struct Wrap<F, P>(F, PhantomData<P>); impl<F, P> Wrap<F, P> { fn new(func: F) -> Self { Self(func, PhantomData) } } trait Arg {} impl Arg for i128 {} impl<F, Fut, A> NodeImpl for Wrap<F, A> where F: Fn(&RuntimeContext, A) -> Fut, Fut: Future<Output = i128>, A: Arg, { } impl<F, Fut, A, B> NodeImpl for Wrap<F, (A, B)> where F: Fn(&RuntimeContext, A, B) -> Fut, Fut: Future<Output = i128>, A: Arg, B: Arg, { } pub fn trigger_ice() { let x: Box<dyn NodeImpl> = Box::new(Wrap::<_, (i128, i128)>::new( async |_context: &RuntimeContext, x: i128, y: i128| 10, )); }Meta
rustc --version --verbose:
rustc 1.92.0-nightly (844264add 2025-10-14) binary: rustc commit-hash: 844264adda6f41ca6d0d61c4bcac0f263fc5072f commit-date: 2025-10-14 host: x86_64-unknown-linux-gnu release: 1.92.0-nightly LLVM version: 21.1.3 Error output
note: no errors encountered even though delayed bugs were created note: those delayed bugs will now be shown as internal compiler errors error: internal compiler error: error performing operation: fully_perform --> src/lib.rs:36:32 | 36 | let x: Box<dyn NodeImpl> = Box::new(Wrap::<_, (i128, i128)>::new( | ________________________________^ 37 | | async |_context: &RuntimeContext, x: i128, y: i128| 10, 38 | | )); | |______^ | note: delayed at /rustc-dev/4b94758d2ba7d0ef71ccf5fde29ce4bc5d6fe2a4/compiler/rustc_trait_selection/src/traits/query/type_op/custom.rs:95:25 --> src/lib.rs:36:32 | 36 | let x: Box<dyn NodeImpl> = Box::new(Wrap::<_, (i128, i128)>::new( | ________________________________^ 37 | | async |_context: &RuntimeContext, x: i128, y: i128| 10, 38 | | )); | |______^ 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: please attach the file at `/playground/rustc-ice-2025-10-15T09_32_10-46.txt` to your bug report note: compiler flags: --crate-type lib -C embed-bitcode=no -C codegen-units=1 -C debuginfo=2 note: some of the compiler flags provided by cargo are hidden Backtrace
0: <rustc_errors::DiagCtxtInner>::emit_diagnostic 1: <rustc_errors::DiagCtxtHandle>::emit_diagnostic 2: <rustc_span::ErrorGuaranteed as rustc_errors::diagnostic::EmissionGuarantee>::emit_producing_guarantee 3: <rustc_errors::DiagCtxtHandle>::span_delayed_bug::<rustc_span::span_encoding::Span, alloc::string::String> 4: <rustc_borrowck::type_check::TypeChecker>::prove_trait_ref 5: <rustc_borrowck::type_check::TypeChecker as rustc_middle::mir::visit::Visitor>::visit_rvalue 6: <rustc_borrowck::type_check::TypeChecker as rustc_middle::mir::visit::Visitor>::visit_body 7: rustc_borrowck::type_check::type_check 8: <rustc_borrowck::root_cx::BorrowCheckRootCtxt>::do_mir_borrowck 9: rustc_borrowck::mir_borrowck 10: rustc_query_impl::plumbing::__rust_begin_short_backtrace::<rustc_query_impl::query_impl::mir_borrowck::dynamic_query::{closure#2}::{closure#0}, rustc_middle::query::erase::Erased<[u8; 8]>> 11: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::DynamicConfig<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false> 12: rustc_query_impl::query_impl::mir_borrowck::get_query_non_incr::__rust_end_short_backtrace 13: <rustc_middle::ty::context::TyCtxt>::par_hir_body_owners::<rustc_interface::passes::run_required_analyses::{closure#1}::{closure#0}>::{closure#0} 14: rustc_interface::passes::analysis 15: rustc_query_impl::plumbing::__rust_begin_short_backtrace::<rustc_query_impl::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle::query::erase::Erased<[u8; 0]>> 16: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::SingleCache<rustc_middle::query::erase::Erased<[u8; 0]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false> 17: rustc_query_impl::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace 18: <rustc_interface::passes::create_and_enter_global_ctxt<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure#2}>::{closure#2} as core::ops::function::FnOnce<(&rustc_session::session::Session, rustc_middle::ty::context::CurrentGcx, alloc::sync::Arc<rustc_data_structures::jobserver::Proxy>, &std::sync::once_lock::OnceLock<rustc_middle::ty::context::GlobalCtxt>, &rustc_data_structures::sync::worker_local::WorkerLocal<rustc_middle::arena::Arena>, &rustc_data_structures::sync::worker_local::WorkerLocal<rustc_hir::Arena>, rustc_driver_impl::run_compiler::{closure#0}::{closure#2})>>::call_once::{shim:vtable#0} 19: rustc_interface::interface::run_compiler::<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1} 20: std::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface::util::run_in_thread_with_globals<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()> 21: <<std::thread::Builder>::spawn_unchecked_<rustc_interface::util::run_in_thread_with_globals<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core::ops::function::FnOnce<()>>::call_once::{shim:vtable#0} 22: std::sys::thread::unix::Thread::new::thread_start 23: <unknown> 24: clone