[ICE]: receiver T/#1 when Self = (dyn Trait<T> + 'static) should have a ScalarPair ABI; found Err(Unknown(T/#1))

[wxie7]

Code

#![feature(arbitrary_self_types, dispatch_from_dyn)]
use std::ops::{Deref, DispatchFromDyn};
trait Trait<T: Deref<Target = Self> + DispatchFromDyn<T>> {
    fn foo(self: T) -> dyn Trait<T>;
}
fn main() {}

Affected release channels

• Previous Stable
• Current Stable
• Current Beta
• Current Nightly

Rust Version

rustc 1.84.0-nightly (bc5cf99 2024-11-05)
binary: rustc
commit-hash: bc5cf99
commit-date: 2024-11-05
host: x86_64-unknown-linux-gnu
release: 1.84.0-nightly
LLVM version: 19.1.3

Current error output

No response

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: <core::iter::adapters::flatten::FlatMap<core::iter::sources::from_fn::FromFn<rustc_type_ir::elaborate::supertrait_def_ids<rustc_middle::ty::context::TyCtxt>::{closure#0}>, alloc::vec::Vec<rustc_middle::traits::DynCompatibilityViolation>, rustc_trait_selection::traits::dyn_compatibility::dyn_compatibility_violations::{closure#0}> as core::iter::traits::iterator::Iterator>::next
     5: rustc_trait_selection::traits::dyn_compatibility::dyn_compatibility_violations
     6: rustc_query_impl::plumbing::__rust_begin_short_backtrace::<rustc_query_impl::query_impl::dyn_compatibility_violations::dynamic_query::{closure#2}::{closure#0}, rustc_middle::query::erase::Erased<[u8; 16]>>
     7: <rustc_query_impl::query_impl::dyn_compatibility_violations::dynamic_query::{closure#2} as core::ops::function::FnOnce<(rustc_middle::ty::context::TyCtxt, rustc_span::def_id::DefId)>>::call_once
     8: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::DefIdCache<rustc_middle::query::erase::Erased<[u8; 16]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false>
     9: rustc_query_impl::query_impl::dyn_compatibility_violations::get_query_non_incr::__rust_end_short_backtrace
    10: rustc_middle::query::plumbing::query_get_at::<rustc_query_system::query::caches::DefIdCache<rustc_middle::query::erase::Erased<[u8; 16]>>>
    11: rustc_trait_selection::traits::dyn_compatibility::is_dyn_compatible
    12: rustc_query_impl::plumbing::__rust_begin_short_backtrace::<rustc_query_impl::query_impl::is_dyn_compatible::dynamic_query::{closure#2}::{closure#0}, rustc_middle::query::erase::Erased<[u8; 1]>>
    13: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::DefIdCache<rustc_middle::query::erase::Erased<[u8; 1]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false>
    14: rustc_query_impl::query_impl::is_dyn_compatible::get_query_non_incr::__rust_end_short_backtrace
    15: rustc_middle::query::plumbing::query_get_at::<rustc_query_system::query::caches::DefIdCache<rustc_middle::query::erase::Erased<[u8; 1]>>>
    16: rustc_hir_analysis::check::wfcheck::check_dyn_incompatible_self_trait_by_name
    17: rustc_hir_analysis::check::wfcheck::check_well_formed
    18: rustc_query_impl::plumbing::__rust_begin_short_backtrace::<rustc_query_impl::query_impl::check_well_formed::dynamic_query::{closure#2}::{closure#0}, rustc_middle::query::erase::Erased<[u8; 1]>>
    19: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 1]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false>
    20: rustc_query_impl::query_impl::check_well_formed::get_query_non_incr::__rust_end_short_backtrace
    21: rustc_middle::query::plumbing::query_ensure_error_guaranteed::<rustc_query_system::query::caches::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 1]>>, ()>
    22: rustc_hir_analysis::check::wfcheck::check_mod_type_wf
    23: rustc_query_impl::plumbing::__rust_begin_short_backtrace::<rustc_query_impl::query_impl::check_mod_type_wf::dynamic_query::{closure#2}::{closure#0}, rustc_middle::query::erase::Erased<[u8; 1]>>
    24: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::DefaultCache<rustc_span::def_id::LocalModDefId, rustc_middle::query::erase::Erased<[u8; 1]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false>
    25: rustc_query_impl::query_impl::check_mod_type_wf::get_query_non_incr::__rust_end_short_backtrace
    26: rustc_hir_analysis::check_crate
    27: rustc_interface::passes::run_required_analyses
    28: rustc_interface::passes::analysis
    29: 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; 1]>>
    30: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::SingleCache<rustc_middle::query::erase::Erased<[u8; 1]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false>
    31: rustc_query_impl::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
    32: rustc_interface::interface::run_compiler::<core::result::Result<(), rustc_span::ErrorGuaranteed>, rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}
    33: 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<core::result::Result<(), rustc_span::ErrorGuaranteed>, rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#0}::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>
    34: <<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<core::result::Result<(), rustc_span::ErrorGuaranteed>, rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#0}::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#1} as core::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
    35: std::sys::pal::unix::thread::Thread::new::thread_start
    36: start_thread
               at ./nptl/pthread_create.c:442:8
    37: __GI___clone3
               at ./misc/../sysdeps/unix/sysv/linux/x86_64/clone3.S:81

Anything else?

note: compiler flags: --crate-type staticlib -C link-dead-code -C debuginfo=2 -C opt-level=3 -Z mir-opt-level=3 (fmease: unnecessary)

[fmease]

Strongly related to (if not duplicate of) #90110 although the latter doesn't require any feature flags.

[matthiaskrgr]

the code is from #57276 , closing as duplicate