Compiler ICEs in a diagnositc "expected a type, found a trait" when Clone and Copy is derived.

[FractalFir]

Code

This is a reduced example.
The nightly compiler panics when attempting to generate a diagnostic for this code:

trait Float{}
#[derive(Clone,Copy)]
struct Sphere{
	rad:Float,
}

The ICE occurs if a trait is used in place of the type of the field, and the struct containing the incorrect field definition is marked with #[derive(Copy,Clone)]. This ICE does not occur in stable or beta.

Meta

rustc --version --verbose:

rustc 1.87.0-nightly (f5a1ef712 2025-03-07)
binary: rustc
commit-hash: f5a1ef7121ad661b5a21a1d02941c8064d54ee0b
commit-date: 2025-03-07
host: x86_64-unknown-linux-gnu
release: 1.87.0-nightly
LLVM version: 20.1.0

Error output

    Checking swiatowid v0.1.0 (/home/michal/swiatowid)
error[E0782]: expected a type, found a trait
 --> src/sphere.rs:4:6
  |
4 |     rad:Float,
  |         ^^^^^
  |
help: you can add the `dyn` keyword if you want a trait object
  |
4 |     rad:dyn Float,
  |         +++


thread 'rustc' panicked at compiler/rustc_hir_analysis/src/hir_ty_lowering/lint.rs:210:61:
$ident: found ImplItem(ImplItem { ident: clone#4, owner_id: DefId(0:9 ~ swiatowid[28cd]::sphere::{impl#0}::clone), generics: Generics { params: [GenericParam { hir_id: HirId(DefId(0:9 ~ swiatowid[28cd]::sphere::{impl#0}::clone).19), def_id: DefId(0:11 ~ swiatowid[28cd]::sphere::{impl#0}::clone::'_), name: Fresh, span: src/sphere.rs:2:10: 2:11 (#4), pure_wrt_drop: false, kind: Lifetime { kind: Elided(Ampersand) }, colon_span: None, source: Generics }], predicates: [], has_where_clause_predicates: false, where_clause_span: src/sphere.rs:2:10: 2:15 (#4), span: src/sphere.rs:2:10: 2:15 (#4) }, kind: Fn(FnSig { header: FnHeader { safety: Normal(Safe), constness: NotConst, asyncness: NotAsync, abi: Rust }, decl: FnDecl { inputs: [Ty { hir_id: HirId(DefId(0:9 ~ swiatowid[28cd]::sphere::{impl#0}::clone).23), span: src/sphere.rs:2:10: 2:15 (#4), kind: Ref(Lifetime { hir_id: HirId(DefId(0:9 ~ swiatowid[28cd]::sphere::{impl#0}::clone).20), ident: '_#4, res: Param(DefId(0:11 ~ swiatowid[28cd]::sphere::{impl#0}::clone::'_)) }, MutTy { ty: Ty { hir_id: HirId(DefId(0:9 ~ swiatowid[28cd]::sphere::{impl#0}::clone).22), span: src/sphere.rs:2:10: 2:15 (#0), kind: Path(Resolved(None, Path { span: src/sphere.rs:2:10: 2:15 (#0), res: SelfTyAlias { alias_to: DefId(0:8 ~ swiatowid[28cd]::sphere::{impl#0}), forbid_generic: false, is_trait_impl: true }, segments: [PathSegment { ident: Self#0, hir_id: HirId(DefId(0:9 ~ swiatowid[28cd]::sphere::{impl#0}::clone).21), res: SelfTyAlias { alias_to: DefId(0:8 ~ swiatowid[28cd]::sphere::{impl#0}), forbid_generic: false, is_trait_impl: true }, args: None, infer_args: true }] })) }, mutbl: Not }) }], output: Return(Ty { hir_id: HirId(DefId(0:9 ~ swiatowid[28cd]::sphere::{impl#0}::clone).24), span: src/sphere.rs:2:10: 2:15 (#4), kind: Path(Resolved(None, Path { span: src/sphere.rs:2:10: 2:10 (#4), res: Def(Struct, DefId(0:6 ~ swiatowid[28cd]::sphere::Sphere)), segments: [PathSegment { ident: Sphere#0, hir_id: HirId(DefId(0:9 ~ swiatowid[28cd]::sphere::{impl#0}::clone).25), res: Def(Struct, DefId(0:6 ~ swiatowid[28cd]::sphere::Sphere)), args: None, infer_args: false }] })) }), c_variadic: false, implicit_self: RefImm, lifetime_elision_allowed: true }, span: src/sphere.rs:2:10: 2:15 (#4) }, BodyId { hir_id: HirId(DefId(0:9 ~ swiatowid[28cd]::sphere::{impl#0}::clone).18) }), defaultness: Final, span: src/sphere.rs:2:10: 2:15 (#4), vis_span: src/sphere.rs:2:10: 2:10 (#4) })

Backtrace

stack backtrace:
   0:     0x7fd4ad3cb634 - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::hc366073dd4ba6a4f
   1:     0x7fd4adc05aa2 - core::fmt::write::hb9256d1d79ff6859
   2:     0x7fd4aef9ddd1 - std::io::Write::write_fmt::hd9a4a51e43d6ab68
   3:     0x7fd4ad3cb492 - std::sys::backtrace::BacktraceLock::print::h81b51ca9905b58b8
   4:     0x7fd4ad3cdd72 - std::panicking::default_hook::{{closure}}::h800cff087746fb32
   5:     0x7fd4ad3cd964 - std::panicking::default_hook::h8e77302320466097
   6:     0x7fd4ac524177 - std[7d1496126c658a52]::panicking::update_hook::<alloc[b94a15b63fd00bf8]::boxed::Box<rustc_driver_impl[95ea3323f115095d]::install_ice_hook::{closure#1}>>::{closure#0}
   7:     0x7fd4ad3ce5e3 - std::panicking::rust_panic_with_hook::hf2880f219899d673
   8:     0x7fd4ad3ce2da - std::panicking::begin_panic_handler::{{closure}}::h42bf1fdcf963f876
   9:     0x7fd4ad3cbb09 - std::sys::backtrace::__rust_end_short_backtrace::hc4c003c597b25946
  10:     0x7fd4ad3cdf9d - rust_begin_unwind
  11:     0x7fd4aa05f240 - core::panicking::panic_fmt::h7ae6caa9a51b5d7e
  12:     0x7fd4ac5f1551 - rustc_hir[6a02ee2565274b65]::hir::expect_failed::<&rustc_hir[6a02ee2565274b65]::hir::Node>
  13:     0x7fd4aee5cd98 - <dyn rustc_hir_analysis[44a464fc9530b13d]::hir_ty_lowering::HirTyLowerer>::prohibit_or_lint_bare_trait_object_ty
  14:     0x7fd4ae3525b6 - <dyn rustc_hir_analysis[44a464fc9530b13d]::hir_ty_lowering::HirTyLowerer>::lower_ty
  15:     0x7fd4ae355628 - <dyn rustc_hir_analysis[44a464fc9530b13d]::hir_ty_lowering::HirTyLowerer>::lower_path
  16:     0x7fd4ae351c5a - <dyn rustc_hir_analysis[44a464fc9530b13d]::hir_ty_lowering::HirTyLowerer>::lower_ty
  17:     0x7fd4aeab6b9d - <rustc_hir_typeck[ad7c24fc563faa0d]::gather_locals::GatherLocalsVisitor>::declare
  18:     0x7fd4ae326b67 - <rustc_hir_typeck[ad7c24fc563faa0d]::gather_locals::GatherLocalsVisitor as rustc_hir[6a02ee2565274b65]::intravisit::Visitor>::visit_expr
  19:     0x7fd4ae327d0d - rustc_hir_typeck[ad7c24fc563faa0d]::check::check_fn
  20:     0x7fd4ae31bc78 - rustc_hir_typeck[ad7c24fc563faa0d]::typeck_with_inspect::{closure#0}
  21:     0x7fd4ae31b270 - rustc_query_impl[ffcc3d1c9e8154f]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[ffcc3d1c9e8154f]::query_impl::typeck::dynamic_query::{closure#2}::{closure#0}, rustc_middle[56e4ff076cda644b]::query::erase::Erased<[u8; 8usize]>>
  22:     0x7fd4adf60d05 - rustc_query_system[973ddc25b5c3187c]::query::plumbing::try_execute_query::<rustc_query_impl[ffcc3d1c9e8154f]::DynamicConfig<rustc_data_structures[16871ea2f26fa4bd]::vec_cache::VecCache<rustc_span[515292683a253d38]::def_id::LocalDefId, rustc_middle[56e4ff076cda644b]::query::erase::Erased<[u8; 8usize]>, rustc_query_system[973ddc25b5c3187c]::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl[ffcc3d1c9e8154f]::plumbing::QueryCtxt, true>
  23:     0x7fd4adf5d307 - rustc_query_impl[ffcc3d1c9e8154f]::query_impl::typeck::get_query_incr::__rust_end_short_backtrace
  24:     0x7fd4adf5ce7f - <rustc_middle[56e4ff076cda644b]::ty::context::TyCtxt>::par_hir_body_owners::<rustc_hir_analysis[44a464fc9530b13d]::check_crate::{closure#3}>::{closure#0}
  25:     0x7fd4adf5c4fb - rustc_hir_analysis[44a464fc9530b13d]::check_crate
  26:     0x7fd4ae0754b2 - rustc_interface[307c5e6bd736cecc]::passes::run_required_analyses
  27:     0x7fd4aeb8637a - rustc_interface[307c5e6bd736cecc]::passes::analysis
  28:     0x7fd4aeb86359 - rustc_query_impl[ffcc3d1c9e8154f]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[ffcc3d1c9e8154f]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[56e4ff076cda644b]::query::erase::Erased<[u8; 0usize]>>
  29:     0x7fd4aeb8172a - rustc_query_system[973ddc25b5c3187c]::query::plumbing::try_execute_query::<rustc_query_impl[ffcc3d1c9e8154f]::DynamicConfig<rustc_query_system[973ddc25b5c3187c]::query::caches::SingleCache<rustc_middle[56e4ff076cda644b]::query::erase::Erased<[u8; 0usize]>>, false, false, false>, rustc_query_impl[ffcc3d1c9e8154f]::plumbing::QueryCtxt, true>
  30:     0x7fd4aeb81236 - rustc_query_impl[ffcc3d1c9e8154f]::query_impl::analysis::get_query_incr::__rust_end_short_backtrace
  31:     0x7fd4aed1623d - rustc_interface[307c5e6bd736cecc]::passes::create_and_enter_global_ctxt::<core[2ed51ce221d9613e]::option::Option<rustc_interface[307c5e6bd736cecc]::queries::Linker>, rustc_driver_impl[95ea3323f115095d]::run_compiler::{closure#0}::{closure#2}>::{closure#2}::{closure#0}
  32:     0x7fd4aed06160 - rustc_interface[307c5e6bd736cecc]::interface::run_compiler::<(), rustc_driver_impl[95ea3323f115095d]::run_compiler::{closure#0}>::{closure#1}
  33:     0x7fd4aeb94588 - std[7d1496126c658a52]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[307c5e6bd736cecc]::util::run_in_thread_with_globals<rustc_interface[307c5e6bd736cecc]::util::run_in_thread_pool_with_globals<rustc_interface[307c5e6bd736cecc]::interface::run_compiler<(), rustc_driver_impl[95ea3323f115095d]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
  34:     0x7fd4aeb94e74 - <<std[7d1496126c658a52]::thread::Builder>::spawn_unchecked_<rustc_interface[307c5e6bd736cecc]::util::run_in_thread_with_globals<rustc_interface[307c5e6bd736cecc]::util::run_in_thread_pool_with_globals<rustc_interface[307c5e6bd736cecc]::interface::run_compiler<(), rustc_driver_impl[95ea3323f115095d]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core[2ed51ce221d9613e]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  35:     0x7fd4aeb96277 - std::sys::pal::unix::thread::Thread::new::thread_start::h39d9c8bec2c62e1a
  36:     0x7fd4a8c7e168 - start_thread
  37:     0x7fd4a8d0214c - __clone3
  38:                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: please attach the file at `/home/michal/swiatowid/rustc-ice-2025-03-09T08_12_30-22110.txt` to your bug report

note: compiler flags: --crate-type bin -C embed-bitcode=no -C debuginfo=2 -C incremental=[REDACTED]

note: some of the compiler flags provided by cargo are hidden

query stack during panic:
#0 [typeck] type-checking `sphere::<impl at src/sphere.rs:2:10: 2:15>::clone`
#1 [analysis] running analysis passes on this crate
end of query stack
For more information about this error, try `rustc --explain E0782`.
error: could not compile `swiatowid` (bin "swiatowid") due to 1 previous error

[matthiaskrgr]

duplicate of #138211 I think