ICE: `Type may implement copy, but there is no other error.`

[matthiaskrgr]

auto-reduced (treereduce-rust):

struct S<T: 'static>( Option<&'static T>);




impl<T: 'static> Copy for S<T> where S<T>: Copy + Clone {}
impl<T: 'static> Clone for S<T>  {
    fn clone(&self) -> Self { *self }
}
fn main() {
    
}

original:

//@ run-pass
struct S<T: 'static>(#[allow(dead_code)] Option<&'static T>);

trait Tr { type Out; }
impl<T> Tr for T { type Out = T; }

impl<T: 'static> Copy for S<T> where S<T>: Copy + Clone {}
impl<T: 'static> Clone for S<T> where S<T>: Tr<Out=T> {
    fn clone(&self) -> Self { *self }
}
fn main() {
    S::<()>(None);
}

Version information

rustc 1.90.0-nightly (82310651b 2025-07-18)
binary: rustc
commit-hash: 82310651b93a594a3fd69015e1562186a080d94c
commit-date: 2025-07-18
host: x86_64-unknown-linux-gnu
release: 1.90.0-nightly
LLVM version: 20.1.8

Command:
/home/matthias/.rustup/toolchains/master/bin/rustc

Program output

warning: struct `S` is never constructed
 --> /tmp/icemaker_global_tempdir.M5kg6WQXJqfU/rustc_testrunner_tmpdir_reporting.PyxBZ6ga2OTn/mvce.rs:2:8
  |
2 | struct S<T: 'static>( Option<&'static T>);
  |        ^
  |
  = note: `#[warn(dead_code)]` on by default

warning: 1 warning emitted

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: Type may implement copy, but there is no other error.
 --> /tmp/icemaker_global_tempdir.M5kg6WQXJqfU/rustc_testrunner_tmpdir_reporting.PyxBZ6ga2OTn/mvce.rs:9:31
  |
9 |     fn clone(&self) -> Self { *self }
  |                               ^^^^^
  |
note: delayed at compiler/rustc_borrowck/src/diagnostics/move_errors.rs:275:28
         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, &str>
         4: <rustc_borrowck::MirBorrowckCtxt>::report
         5: rustc_borrowck::do_mir_borrowck
         6: rustc_borrowck::mir_borrowck
         7: 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]>>
         8: 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>
         9: rustc_query_impl::query_impl::mir_borrowck::get_query_non_incr::__rust_end_short_backtrace
        10: <rustc_middle::ty::context::TyCtxt>::par_hir_body_owners::<rustc_interface::passes::run_required_analyses::{closure#1}::{closure#0}>::{closure#0}
        11: rustc_interface::passes::analysis
        12: 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]>>
        13: 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>
        14: rustc_query_impl::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
        15: 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}::{closure#0}
        16: rustc_interface::interface::run_compiler::<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}
        17: 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}, ()>
        18: <<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}
        19: std::sys::pal::unix::thread::Thread::new::thread_start
        20: <unknown>
        21: <unknown>
 --> /tmp/icemaker_global_tempdir.M5kg6WQXJqfU/rustc_testrunner_tmpdir_reporting.PyxBZ6ga2OTn/mvce.rs:9:31
  |
9 |     fn clone(&self) -> Self { *self }
  |                               ^^^^^

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 1.90.0-nightly (82310651b 2025-07-18) running on x86_64-unknown-linux-gnu

query stack during panic:
end of query stack

[matthiaskrgr]

struct S<T: 'static>(Option<&'static T>);
impl<T: 'static> Copy for S<T> where S<T>: Copy + Clone {}
impl<T: 'static> Clone for S<T> {
    fn clone(&self) -> Self {
        *self
    }
}
fn main() {}

bisects to
nightly-2024-11-06

[cyrgani]

struct S<T: 'static>(&'static T);
impl<T> Copy for S<T> where S<T>: Copy {}
impl<T> Clone for S<T> {
    fn clone(&self) -> Self {
        *self
    }
}