warning: the feature `fn_delegation` is incomplete and may not be safe to use and/or cause compiler crashes
--> /tmp/icemaker_global_tempdir.FOTYhPGUBckV/rustc_testrunner_tmpdir_reporting.W5Ae5KwyzJd6/mvce.rs:1:12
|
1 | #![feature(fn_delegation)]
| ^^^^^^^^^^^^^
|
= note: see issue #118212 <https://github.com/rust-lang/rust/issues/118212> for more information
= note: `#[warn(incomplete_features)]` on by default
warning: trait `Trait` is never used
--> /tmp/icemaker_global_tempdir.FOTYhPGUBckV/rustc_testrunner_tmpdir_reporting.W5Ae5KwyzJd6/mvce.rs:3:7
|
3 | trait Trait {
| ^^^^^
|
= note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
warning: struct `F` is never constructed
--> /tmp/icemaker_global_tempdir.FOTYhPGUBckV/rustc_testrunner_tmpdir_reporting.W5Ae5KwyzJd6/mvce.rs:7:8
|
7 | struct F;
| ^
warning: struct `S` is never constructed
--> /tmp/icemaker_global_tempdir.FOTYhPGUBckV/rustc_testrunner_tmpdir_reporting.W5Ae5KwyzJd6/mvce.rs:10:8
|
10 | struct S(F);
| ^
warning: associated items `foo` and `bar` are never used
--> /tmp/icemaker_global_tempdir.FOTYhPGUBckV/rustc_testrunner_tmpdir_reporting.W5Ae5KwyzJd6/mvce.rs:12:18
|
11 | impl S {
| ------ associated items in this implementation
12 | reuse Trait::foo::<> { self.0 }
| ^^^
13 |
14 | reuse Self::foo::<'_> as bar { self.0 }
| ^^^
warning: 5 warnings 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: failed to resolve delegation to inherent impl
--> /tmp/icemaker_global_tempdir.FOTYhPGUBckV/rustc_testrunner_tmpdir_reporting.W5Ae5KwyzJd6/mvce.rs:14:17
|
14 | reuse Self::foo::<'_> as bar { self.0 }
| ^^^
|
note: delayed at /rustc-dev/a8a1e6fd9df2e094d6f09c0d57991508680acc1c/compiler/rustc_ast_lowering/src/delegation/resolution.rs:83:68
0: <rustc_errors::DiagCtxtInner>::emit_diagnostic
1: <rustc_errors::DiagCtxtHandle>::emit_diagnostic
2: <rustc_errors::diagnostic::Diag>::emit
3: <rustc_errors::DiagCtxtHandle>::span_delayed_bug::<rustc_span::span_encoding::Span, &str>
4: rustc_ast_lowering::delegation::resolution::resolve_type_relative_delegations
5: rustc_query_impl::query_vtables::resolve_type_relative_delegations::invoke_provider_fn::__rust_begin_short_backtrace
6: rustc_query_impl::execution::try_execute_query::<rustc_middle::query::caches::SingleCache<rustc_middle::query::erase::ErasedData<[u8; 8]>>, false>
7: rustc_query_impl::query_vtables::resolve_type_relative_delegations::execute_query_non_incr::__rust_end_short_backtrace
8: rustc_ast_lowering::lower_to_hir
9: rustc_query_impl::query_vtables::lower_to_hir::invoke_provider_fn::__rust_begin_short_backtrace
10: rustc_query_impl::execution::try_execute_query::<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::ErasedData<[u8; 16]>, rustc_middle::dep_graph::graph::DepNodeIndex>, false>
11: rustc_query_impl::query_vtables::lower_to_hir::execute_query_non_incr::__rust_end_short_backtrace
12: rustc_query_impl::query_vtables::hir_owner::invoke_provider_fn::__rust_begin_short_backtrace
13: rustc_query_impl::execution::try_execute_query::<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::ErasedData<[u8; 32]>, rustc_middle::dep_graph::graph::DepNodeIndex>, false>
14: rustc_query_impl::query_vtables::hir_owner::execute_query_non_incr::__rust_end_short_backtrace
15: <rustc_middle::ty::context::TyCtxt>::expect_hir_owner_nodes
16: rustc_middle::hir::map::hir_crate_items
17: rustc_query_impl::query_vtables::hir_crate_items::invoke_provider_fn::__rust_begin_short_backtrace
18: rustc_query_impl::execution::try_execute_query::<rustc_middle::query::caches::SingleCache<rustc_middle::query::erase::ErasedData<[u8; 8]>>, false>
19: rustc_query_impl::query_vtables::hir_crate_items::execute_query_non_incr::__rust_end_short_backtrace
20: rustc_interface::passes::analysis
21: rustc_query_impl::execution::try_execute_query::<rustc_middle::query::caches::SingleCache<rustc_middle::query::erase::ErasedData<[u8; 0]>>, false>
22: rustc_query_impl::query_vtables::analysis::execute_query_non_incr::__rust_end_short_backtrace
23: rustc_interface::interface::run_compiler::<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#2}
24: 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#2}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
25: <std::thread::lifecycle::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#2}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
26: <std::sys::thread::unix::Thread>::new::thread_start
27: <unknown>
28: <unknown>
--> /tmp/icemaker_global_tempdir.FOTYhPGUBckV/rustc_testrunner_tmpdir_reporting.W5Ae5KwyzJd6/mvce.rs:14:17
|
14 | reuse Self::foo::<'_> as bar { self.0 }
| ^^^
error: internal compiler error: `Res::Err` but no error emitted
--> /tmp/icemaker_global_tempdir.FOTYhPGUBckV/rustc_testrunner_tmpdir_reporting.W5Ae5KwyzJd6/mvce.rs:14:36
|
14 | reuse Self::foo::<'_> as bar { self.0 }
| ^^^^
|
note: delayed at /rustc-dev/a8a1e6fd9df2e094d6f09c0d57991508680acc1c/compiler/rustc_hir_typeck/src/expr.rs:598:32
0: <rustc_errors::DiagCtxtInner>::emit_diagnostic
1: <rustc_errors::DiagCtxtHandle>::emit_diagnostic
2: <rustc_errors::diagnostic::Diag>::emit
3: <rustc_errors::DiagCtxtHandle>::span_delayed_bug::<rustc_span::span_encoding::Span, &str>
4: <rustc_hir_typeck::fn_ctxt::FnCtxt>::check_expr_path
5: <rustc_hir_typeck::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
6: <rustc_hir_typeck::fn_ctxt::FnCtxt>::check_expr_field
7: <rustc_hir_typeck::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
8: <rustc_hir_typeck::fn_ctxt::FnCtxt>::check_expr_block
9: <rustc_hir_typeck::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
10: <rustc_hir_typeck::fn_ctxt::FnCtxt>::check_expr_call
11: <rustc_hir_typeck::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
12: <rustc_hir_typeck::fn_ctxt::FnCtxt>::check_expr_block
13: <rustc_hir_typeck::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
14: rustc_hir_typeck::check::check_fn
15: rustc_hir_typeck::typeck_with_inspect::{closure#0}
16: rustc_query_impl::query_vtables::typeck_root::invoke_provider_fn::__rust_begin_short_backtrace
17: rustc_query_impl::execution::try_execute_query::<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::ErasedData<[u8; 8]>, rustc_middle::dep_graph::graph::DepNodeIndex>, false>
18: rustc_query_impl::query_vtables::typeck_root::execute_query_non_incr::__rust_end_short_backtrace
19: <rustc_middle::ty::context::TyCtxt>::par_hir_body_owners::<rustc_hir_analysis::check_crate::{closure#1}>::{closure#0}
20: rustc_hir_analysis::check_crate
21: rustc_interface::passes::analysis
22: rustc_query_impl::execution::try_execute_query::<rustc_middle::query::caches::SingleCache<rustc_middle::query::erase::ErasedData<[u8; 0]>>, false>
23: rustc_query_impl::query_vtables::analysis::execute_query_non_incr::__rust_end_short_backtrace
24: rustc_interface::interface::run_compiler::<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#2}
25: 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#2}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
26: <std::thread::lifecycle::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#2}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
27: <std::sys::thread::unix::Thread>::new::thread_start
28: <unknown>
29: <unknown>
--> /tmp/icemaker_global_tempdir.FOTYhPGUBckV/rustc_testrunner_tmpdir_reporting.W5Ae5KwyzJd6/mvce.rs:14:36
|
14 | reuse Self::foo::<'_> as bar { self.0 }
| ^^^^
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 1.100.0-nightly (a8a1e6fd9 2026-09-14) running on x86_64-unknown-linux-gnu
query stack during panic:
end of query stack
auto-reduced (treereduce-rust):
original:
Version information
Command:
/home/matthias/.rustup/toolchains/master/bin/rustcProgram output
@rustbot label +F-fn_delegation