ICE: debug assertions: E0061 suggests garbage code if struct name == fn name

[matthiaskrgr]

Code

You need debug assertions for the ice!

#![crate_type="lib"]

#[derive(Clone)]
struct A<T, U>(T, U);

fn A() {}

Meta

rustc --version --verbose:

<version>

Error output

error[E0428]: the name `A` is defined multiple times
 --> EE2C38A2D5621C3FBE37D753F1BC19AFC487F6962D8B7E352367BEA9C0337700.rs:6:1
  |
4 | struct A<T, U>(T, U);
  | --------------------- previous definition of the value `A` here
5 |
6 | fn A() {}
  | ^^^^^^ `A` redefined here
  |
  = note: `A` must be defined only once in the value namespace of this module

error[E0061]: this function takes 0 arguments but 2 arguments were supplied
 --> EE2C38A2D5621C3FBE37D753F1BC19AFC487F6962D8B7E352367BEA9C0337700.rs:3:10
  |
3 | #[derive(Clone)]
  |          ^^^^^
4 | struct A<T, U>(T, U);
  |                -  - unexpected argument of type `U`
  |                |
  |                unexpected argument of type `T`
  |
note: function defined here
 --> EE2C38A2D5621C3FBE37D753F1BC19AFC487F6962D8B7E352367BEA9C0337700.rs:6:4
  |
6 | fn A() {}
  |    ^
  = note: this error originates in the derive macro `Clone` (in Nightly builds, run with -Z macro-backtrace for more info)
help: remove the extra arguments
  |
3 - #[derive(Clone)]
4 - struct A<T, U>(T, U);
3 + #[derive(Clon, U);
  |

error[E0308]: mismatched types
 --> EE2C38A2D5621C3FBE37D753F1BC19AFC487F6962D8B7E352367BEA9C0337700.rs:3:10
  |
3 | #[derive(Clone)]
  |          ^^^^^
  |          |
  |          expected `A<T, U>`, found `()`
  |          expected `A<T, U>` because of return type
  |
  = note: expected struct `A<T, U>`
          found unit type `()`
  = note: this error originates in the derive macro `Clone` (in Nightly builds, run with -Z macro-backtrace for more info)

error: aborting due to 3 previous errors

Some errors have detailed explanations: E0061, E0308, E0428.
For more information about an error, try `rustc --explain E0061`.

The

3 - #[derive(Clone)]
4 - struct A<T, U>(T, U);
3 + #[derive(Clon, U);

part is especially interesting 😆

Backtrace

error[E0428]: the name `A` is defined multiple times
 --> EE2C38A2D5621C3FBE37D753F1BC19AFC487F6962D8B7E352367BEA9C0337700.rs:6:1
  |
4 | struct A<T, U>(T, U);
  | --------------------- previous definition of the value `A` here
5 |
6 | fn A() {}
  | ^^^^^^ `A` redefined here
  |
  = note: `A` must be defined only once in the value namespace of this module
thread 'rustc' panicked at 'assertion failed: `(left == right)`
  left: `Some([SubstitutionPart { span: EE2C38A2D5621C3FBE37D753F1BC19AFC487F6962D8B7E352367BEA9C0337700.rs:3:14: 4:17 (#4), snippet: "" }, SubstitutionPart { span: EE2C38A2D5621C3FBE37D753F1BC19AFC487F6962D8B7E352367BEA9C0337700.rs:4:16: 4:17 (#4), snippet: "" }])`,
 right: `None`: suggestion must not have overlapping parts', /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_errors/src/diagnostic.rs:632:9
stack backtrace:
   0:     0x7fc8e32feeb0 - std::backtrace_rs::backtrace::libunwind::trace::hbf78ef88fed844ac
                               at /home/matthias/vcs/github/rust_debug_assertions/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5
   1:     0x7fc8e32feeb0 - std::backtrace_rs::backtrace::trace_unsynchronized::h35213943d90d267c
                               at /home/matthias/vcs/github/rust_debug_assertions/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7fc8e32feeb0 - std::sys_common::backtrace::_print_fmt::h22ba8bfb93a0a925
                               at /home/matthias/vcs/github/rust_debug_assertions/library/std/src/sys_common/backtrace.rs:65:5
   3:     0x7fc8e32feeb0 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h4d082456b766373f
                               at /home/matthias/vcs/github/rust_debug_assertions/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x7fc8e33adec8 - core::fmt::write::he3860e7dd81c785d
                               at /home/matthias/vcs/github/rust_debug_assertions/library/core/src/fmt/mod.rs:1247:17
   5:     0x7fc8e331403f - std::io::Write::write_fmt::he5c3c49e127ce77e
                               at /home/matthias/vcs/github/rust_debug_assertions/library/std/src/io/mod.rs:1712:15
   6:     0x7fc8e32fecb5 - std::sys_common::backtrace::_print::hbf9982c7c009c352
                               at /home/matthias/vcs/github/rust_debug_assertions/library/std/src/sys_common/backtrace.rs:47:5
   7:     0x7fc8e32fecb5 - std::sys_common::backtrace::print::h8ed700e06ac6907c
                               at /home/matthias/vcs/github/rust_debug_assertions/library/std/src/sys_common/backtrace.rs:34:9
   8:     0x7fc8e333d1c3 - std::panicking::default_hook::{{closure}}::h51962e62c530968d
   9:     0x7fc8e333cdf9 - std::panicking::default_hook::h4d87bf54451529eb
                               at /home/matthias/vcs/github/rust_debug_assertions/library/std/src/panicking.rs:293:9
  10:     0x7fc8e5b70905 - <alloc[32b43e9536c01a3]::boxed::Box<dyn for<'a, 'b> core[c5d5d662f7508502]::ops::function::Fn<(&'a core[c5d5d662f7508502]::panic::panic_info::PanicInfo<'b>,), Output = ()> + core[c5d5d662f7508502]::marker::Send + core[c5d5d662f7508502]::marker::Sync> as core[c5d5d662f7508502]::ops::function::Fn<(&core[c5d5d662f7508502]::panic::panic_info::PanicInfo,)>>::call
                               at /home/matthias/vcs/github/rust_debug_assertions/library/alloc/src/boxed.rs:1976:9
  11:     0x7fc8e5b70905 - rustc_driver_impl[17d9f77bedede00f]::DEFAULT_HOOK::{closure#0}::{closure#0}
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_driver_impl/src/lib.rs:1208:17
  12:     0x7fc8e333db12 - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::hadc44a34952fbfd6
                               at /home/matthias/vcs/github/rust_debug_assertions/library/alloc/src/boxed.rs:1976:9
  13:     0x7fc8e333db12 - std::panicking::rust_panic_with_hook::h5a54165269cb41b9
                               at /home/matthias/vcs/github/rust_debug_assertions/library/std/src/panicking.rs:704:13
  14:     0x7fc8e32ff68e - std::panicking::begin_panic_handler::{{closure}}::h20e65ba4620c9639
                               at /home/matthias/vcs/github/rust_debug_assertions/library/std/src/panicking.rs:595:13
  15:     0x7fc8e32fef96 - std::sys_common::backtrace::__rust_end_short_backtrace::heb6999246060ea55
                               at /home/matthias/vcs/github/rust_debug_assertions/library/std/src/sys_common/backtrace.rs:150:18
  16:     0x7fc8e333d652 - rust_begin_unwind
                               at /home/matthias/vcs/github/rust_debug_assertions/library/std/src/panicking.rs:584:5
  17:     0x7fc8e33c8373 - core::panicking::panic_fmt::h446694351a19189a
                               at /home/matthias/vcs/github/rust_debug_assertions/library/core/src/panicking.rs:67:14
  18:     0x7fc8e33c8a33 - core::panicking::assert_failed_inner::hf5d9d5304461a0b9
  19:     0x7fc8e624eae9 - core[c5d5d662f7508502]::panicking::assert_failed::<core[c5d5d662f7508502]::option::Option<&[rustc_errors[a8991bf26d602792]::SubstitutionPart; 2usize]>, core[c5d5d662f7508502]::option::Option<&[rustc_errors[a8991bf26d602792]::SubstitutionPart; 2usize]>>
                               at /home/matthias/vcs/github/rust_debug_assertions/library/core/src/panicking.rs:228:5
  20:     0x7fc8e6375c45 - <rustc_errors[a8991bf26d602792]::diagnostic::Diagnostic>::multipart_suggestion_with_style::<&alloc[32b43e9536c01a3]::string::String>
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_errors/src/diagnostic.rs:632:9
  21:     0x7fc8e618972b - <rustc_errors[a8991bf26d602792]::diagnostic::Diagnostic>::multipart_suggestion::<&alloc[32b43e9536c01a3]::string::String>
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_errors/src/diagnostic.rs:588:9
  22:     0x7fc8e618972b - <rustc_errors[a8991bf26d602792]::diagnostic_builder::DiagnosticBuilder<rustc_span[586fe534fb00e1b1]::ErrorGuaranteed>>::multipart_suggestion::<&alloc[32b43e9536c01a3]::string::String>
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_errors/src/diagnostic_builder.rs:481:35
  23:     0x7fc8e618972b - <rustc_hir_typeck[6b842261c8b16f1c]::fn_ctxt::FnCtxt>::report_arg_errors
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs:1221:17
  24:     0x7fc8e6184e79 - <rustc_hir_typeck[6b842261c8b16f1c]::fn_ctxt::FnCtxt>::check_argument_types
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs:453:13
  25:     0x7fc8e614871f - <rustc_hir_typeck[6b842261c8b16f1c]::fn_ctxt::FnCtxt>::confirm_builtin_call
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_hir_typeck/src/callee.rs:460:9
  26:     0x7fc8e6146ccc - <rustc_hir_typeck[6b842261c8b16f1c]::fn_ctxt::FnCtxt>::check_call
  27:     0x7fc8e61df4e9 - <rustc_hir_typeck[6b842261c8b16f1c]::fn_ctxt::FnCtxt>::check_expr_kind
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_hir_typeck/src/expr.rs:336:45
  28:     0x7fc8e61620ec - <rustc_hir_typeck[6b842261c8b16f1c]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args::{closure#0}
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_hir_typeck/src/expr.rs:240:18
  29:     0x7fc8e61620ec - stacker[f871904c967749]::maybe_grow::<rustc_middle[8ef286a0c1cfdec]::ty::Ty, <rustc_hir_typeck[6b842261c8b16f1c]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args::{closure#0}>
                               at /home/matthias/.cargo/registry/src/github.com-1ecc6299db9ec823/stacker-0.1.15/src/lib.rs:55:9
  30:     0x7fc8e61620ec - rustc_data_structures[e2bc31891c4386a2]::stack::ensure_sufficient_stack::<rustc_middle[8ef286a0c1cfdec]::ty::Ty, <rustc_hir_typeck[6b842261c8b16f1c]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args::{closure#0}>
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_data_structures/src/stack.rs:17:5
  31:     0x7fc8e61620ec - <rustc_hir_typeck[6b842261c8b16f1c]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_hir_typeck/src/expr.rs:236:18
  32:     0x7fc8e61ddea2 - <rustc_hir_typeck[6b842261c8b16f1c]::fn_ctxt::FnCtxt>::check_expr_with_expectation
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_hir_typeck/src/expr.rs:190:9
  33:     0x7fc8e618dc99 - <rustc_hir_typeck[6b842261c8b16f1c]::fn_ctxt::FnCtxt>::check_block_with_expected::{closure#0}::{closure#0}
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs:1551:50
  34:     0x7fc8e618dc99 - <core[c5d5d662f7508502]::option::Option<&&rustc_hir[6b5be662643facdd]::hir::Expr>>::map::<rustc_middle[8ef286a0c1cfdec]::ty::Ty, <rustc_hir_typeck[6b842261c8b16f1c]::fn_ctxt::FnCtxt>::check_block_with_expected::{closure#0}::{closure#0}>
                               at /home/matthias/vcs/github/rust_debug_assertions/library/core/src/option.rs:1089:29
  35:     0x7fc8e618dc99 - <rustc_hir_typeck[6b842261c8b16f1c]::fn_ctxt::FnCtxt>::check_block_with_expected::{closure#0}
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs:1551:42
  36:     0x7fc8e618dc99 - <rustc_hir_typeck[6b842261c8b16f1c]::fn_ctxt::FnCtxt>::with_breakable_ctxt::<<rustc_hir_typeck[6b842261c8b16f1c]::fn_ctxt::FnCtxt>::check_block_with_expected::{closure#0}, ()>
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs:1468:22
  37:     0x7fc8e618dc99 - <rustc_hir_typeck[6b842261c8b16f1c]::fn_ctxt::FnCtxt>::check_block_with_expected
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs:1544:26
  38:     0x7fc8e61df139 - <rustc_hir_typeck[6b842261c8b16f1c]::fn_ctxt::FnCtxt>::check_expr_kind
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_hir_typeck/src/expr.rs:335:41
  39:     0x7fc8e61620ec - <rustc_hir_typeck[6b842261c8b16f1c]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args::{closure#0}
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_hir_typeck/src/expr.rs:240:18
  40:     0x7fc8e61620ec - stacker[f871904c967749]::maybe_grow::<rustc_middle[8ef286a0c1cfdec]::ty::Ty, <rustc_hir_typeck[6b842261c8b16f1c]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args::{closure#0}>
                               at /home/matthias/.cargo/registry/src/github.com-1ecc6299db9ec823/stacker-0.1.15/src/lib.rs:55:9
  41:     0x7fc8e61620ec - rustc_data_structures[e2bc31891c4386a2]::stack::ensure_sufficient_stack::<rustc_middle[8ef286a0c1cfdec]::ty::Ty, <rustc_hir_typeck[6b842261c8b16f1c]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args::{closure#0}>
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_data_structures/src/stack.rs:17:5
  42:     0x7fc8e61620ec - <rustc_hir_typeck[6b842261c8b16f1c]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_hir_typeck/src/expr.rs:236:18
  43:     0x7fc8e61ddea2 - <rustc_hir_typeck[6b842261c8b16f1c]::fn_ctxt::FnCtxt>::check_expr_with_expectation
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_hir_typeck/src/expr.rs:190:9
  44:     0x7fc8e6163f36 - <rustc_hir_typeck[6b842261c8b16f1c]::fn_ctxt::FnCtxt>::check_expr_with_hint
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_hir_typeck/src/expr.rs:142:9
  45:     0x7fc8e6163f36 - <rustc_hir_typeck[6b842261c8b16f1c]::fn_ctxt::FnCtxt>::check_return_expr
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_hir_typeck/src/expr.rs:832:30
  46:     0x7fc8e6369297 - rustc_hir_typeck[6b842261c8b16f1c]::check::check_fn
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_hir_typeck/src/check.rs:122:9
  47:     0x7fc8e6292924 - rustc_hir_typeck[6b842261c8b16f1c]::typeck_with_fallback::<rustc_hir_typeck[6b842261c8b16f1c]::typeck::{closure#0}>::{closure#0}
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_hir_typeck/src/lib.rs:215:9
  48:     0x7fc8e6292924 - rustc_hir_typeck[6b842261c8b16f1c]::typeck_with_fallback::<rustc_hir_typeck[6b842261c8b16f1c]::typeck::{closure#0}>
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_hir_typeck/src/lib.rs:175:36
  49:     0x7fc8e6292924 - rustc_hir_typeck[6b842261c8b16f1c]::typeck
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_hir_typeck/src/lib.rs:157:5
  50:     0x7fc8e776a9bc - <rustc_query_impl[d1b11ab99dd699c5]::queries::typeck as rustc_query_system[5cd5da38e1781535]::query::config::QueryConfig<rustc_query_impl[d1b11ab99dd699c5]::plumbing::QueryCtxt>>::compute
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_query_impl/src/plumbing.rs:524:21
  51:     0x7fc8e776a9bc - rustc_query_system[5cd5da38e1781535]::query::plumbing::execute_job_non_incr::<rustc_query_impl[d1b11ab99dd699c5]::queries::typeck, rustc_query_impl[d1b11ab99dd699c5]::plumbing::QueryCtxt>::{closure#0}
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_query_system/src/query/plumbing.rs:464:72
  52:     0x7fc8e776a9bc - rustc_middle[8ef286a0c1cfdec]::ty::context::tls::enter_context::<rustc_query_system[5cd5da38e1781535]::query::plumbing::execute_job_non_incr<rustc_query_impl[d1b11ab99dd699c5]::queries::typeck, rustc_query_impl[d1b11ab99dd699c5]::plumbing::QueryCtxt>::{closure#0}, rustc_middle[8ef286a0c1cfdec]::query::erase::Erased<[u8; 8usize]>>::{closure#0}
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_middle/src/ty/context/tls.rs:82:9
  53:     0x7fc8e776a9bc - <std[876bbee9698a2b49]::thread::local::LocalKey<core[c5d5d662f7508502]::cell::Cell<*const ()>>>::try_with::<rustc_middle[8ef286a0c1cfdec]::ty::context::tls::enter_context<rustc_query_system[5cd5da38e1781535]::query::plumbing::execute_job_non_incr<rustc_query_impl[d1b11ab99dd699c5]::queries::typeck, rustc_query_impl[d1b11ab99dd699c5]::plumbing::QueryCtxt>::{closure#0}, rustc_middle[8ef286a0c1cfdec]::query::erase::Erased<[u8; 8usize]>>::{closure#0}, rustc_middle[8ef286a0c1cfdec]::query::erase::Erased<[u8; 8usize]>>
                               at /home/matthias/vcs/github/rust_debug_assertions/library/std/src/thread/local.rs:252:16
  54:     0x7fc8e776a9bc - <std[876bbee9698a2b49]::thread::local::LocalKey<core[c5d5d662f7508502]::cell::Cell<*const ()>>>::with::<rustc_middle[8ef286a0c1cfdec]::ty::context::tls::enter_context<rustc_query_system[5cd5da38e1781535]::query::plumbing::execute_job_non_incr<rustc_query_impl[d1b11ab99dd699c5]::queries::typeck, rustc_query_impl[d1b11ab99dd699c5]::plumbing::QueryCtxt>::{closure#0}, rustc_middle[8ef286a0c1cfdec]::query::erase::Erased<[u8; 8usize]>>::{closure#0}, rustc_middle[8ef286a0c1cfdec]::query::erase::Erased<[u8; 8usize]>>
                               at /home/matthias/vcs/github/rust_debug_assertions/library/std/src/thread/local.rs:228:9
  55:     0x7fc8e776a9bc - rustc_middle[8ef286a0c1cfdec]::ty::context::tls::enter_context::<rustc_query_system[5cd5da38e1781535]::query::plumbing::execute_job_non_incr<rustc_query_impl[d1b11ab99dd699c5]::queries::typeck, rustc_query_impl[d1b11ab99dd699c5]::plumbing::QueryCtxt>::{closure#0}, rustc_middle[8ef286a0c1cfdec]::query::erase::Erased<[u8; 8usize]>>
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_middle/src/ty/context/tls.rs:79:9
  56:     0x7fc8e776a9bc - <rustc_query_impl[d1b11ab99dd699c5]::plumbing::QueryCtxt as rustc_query_system[5cd5da38e1781535]::query::QueryContext>::start_query::<rustc_middle[8ef286a0c1cfdec]::query::erase::Erased<[u8; 8usize]>, rustc_query_system[5cd5da38e1781535]::query::plumbing::execute_job_non_incr<rustc_query_impl[d1b11ab99dd699c5]::queries::typeck, rustc_query_impl[d1b11ab99dd699c5]::plumbing::QueryCtxt>::{closure#0}>::{closure#0}
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_query_impl/src/plumbing.rs:127:13
  57:     0x7fc8e776a9bc - rustc_middle[8ef286a0c1cfdec]::ty::context::tls::with_related_context::<<rustc_query_impl[d1b11ab99dd699c5]::plumbing::QueryCtxt as rustc_query_system[5cd5da38e1781535]::query::QueryContext>::start_query<rustc_middle[8ef286a0c1cfdec]::query::erase::Erased<[u8; 8usize]>, rustc_query_system[5cd5da38e1781535]::query::plumbing::execute_job_non_incr<rustc_query_impl[d1b11ab99dd699c5]::queries::typeck, rustc_query_impl[d1b11ab99dd699c5]::plumbing::QueryCtxt>::{closure#0}>::{closure#0}, rustc_middle[8ef286a0c1cfdec]::query::erase::Erased<[u8; 8usize]>>::{closure#0}
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_middle/src/ty/context/tls.rs:133:9
  58:     0x7fc8e776a9bc - rustc_middle[8ef286a0c1cfdec]::ty::context::tls::with_context::<rustc_middle[8ef286a0c1cfdec]::ty::context::tls::with_related_context<<rustc_query_impl[d1b11ab99dd699c5]::plumbing::QueryCtxt as rustc_query_system[5cd5da38e1781535]::query::QueryContext>::start_query<rustc_middle[8ef286a0c1cfdec]::query::erase::Erased<[u8; 8usize]>, rustc_query_system[5cd5da38e1781535]::query::plumbing::execute_job_non_incr<rustc_query_impl[d1b11ab99dd699c5]::queries::typeck, rustc_query_impl[d1b11ab99dd699c5]::plumbing::QueryCtxt>::{closure#0}>::{closure#0}, rustc_middle[8ef286a0c1cfdec]::query::erase::Erased<[u8; 8usize]>>::{closure#0}, rustc_middle[8ef286a0c1cfdec]::query::erase::Erased<[u8; 8usize]>>::{closure#0}
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_middle/src/ty/context/tls.rs:111:36
  59:     0x7fc8e776a9bc - rustc_middle[8ef286a0c1cfdec]::ty::context::tls::with_context_opt::<rustc_middle[8ef286a0c1cfdec]::ty::context::tls::with_context<rustc_middle[8ef286a0c1cfdec]::ty::context::tls::with_related_context<<rustc_query_impl[d1b11ab99dd699c5]::plumbing::QueryCtxt as rustc_query_system[5cd5da38e1781535]::query::QueryContext>::start_query<rustc_middle[8ef286a0c1cfdec]::query::erase::Erased<[u8; 8usize]>, rustc_query_system[5cd5da38e1781535]::query::plumbing::execute_job_non_incr<rustc_query_impl[d1b11ab99dd699c5]::queries::typeck, rustc_query_impl[d1b11ab99dd699c5]::plumbing::QueryCtxt>::{closure#0}>::{closure#0}, rustc_middle[8ef286a0c1cfdec]::query::erase::Erased<[u8; 8usize]>>::{closure#0}, rustc_middle[8ef286a0c1cfdec]::query::erase::Erased<[u8; 8usize]>>::{closure#0}, rustc_middle[8ef286a0c1cfdec]::query::erase::Erased<[u8; 8usize]>>
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_middle/src/ty/context/tls.rs:100:18
  60:     0x7fc8e776a9bc - rustc_middle[8ef286a0c1cfdec]::ty::context::tls::with_context::<rustc_middle[8ef286a0c1cfdec]::ty::context::tls::with_related_context<<rustc_query_impl[d1b11ab99dd699c5]::plumbing::QueryCtxt as rustc_query_system[5cd5da38e1781535]::query::QueryContext>::start_query<rustc_middle[8ef286a0c1cfdec]::query::erase::Erased<[u8; 8usize]>, rustc_query_system[5cd5da38e1781535]::query::plumbing::execute_job_non_incr<rustc_query_impl[d1b11ab99dd699c5]::queries::typeck, rustc_query_impl[d1b11ab99dd699c5]::plumbing::QueryCtxt>::{closure#0}>::{closure#0}, rustc_middle[8ef286a0c1cfdec]::query::erase::Erased<[u8; 8usize]>>::{closure#0}, rustc_middle[8ef286a0c1cfdec]::query::erase::Erased<[u8; 8usize]>>
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_middle/src/ty/context/tls.rs:111:5
  61:     0x7fc8e776a9bc - rustc_middle[8ef286a0c1cfdec]::ty::context::tls::with_related_context::<<rustc_query_impl[d1b11ab99dd699c5]::plumbing::QueryCtxt as rustc_query_system[5cd5da38e1781535]::query::QueryContext>::start_query<rustc_middle[8ef286a0c1cfdec]::query::erase::Erased<[u8; 8usize]>, rustc_query_system[5cd5da38e1781535]::query::plumbing::execute_job_non_incr<rustc_query_impl[d1b11ab99dd699c5]::queries::typeck, rustc_query_impl[d1b11ab99dd699c5]::plumbing::QueryCtxt>::{closure#0}>::{closure#0}, rustc_middle[8ef286a0c1cfdec]::query::erase::Erased<[u8; 8usize]>>
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_middle/src/ty/context/tls.rs:124:5
  62:     0x7fc8e776a9bc - <rustc_query_impl[d1b11ab99dd699c5]::plumbing::QueryCtxt as rustc_query_system[5cd5da38e1781535]::query::QueryContext>::start_query::<rustc_middle[8ef286a0c1cfdec]::query::erase::Erased<[u8; 8usize]>, rustc_query_system[5cd5da38e1781535]::query::plumbing::execute_job_non_incr<rustc_query_impl[d1b11ab99dd699c5]::queries::typeck, rustc_query_impl[d1b11ab99dd699c5]::plumbing::QueryCtxt>::{closure#0}>
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_query_impl/src/plumbing.rs:112:9
  63:     0x7fc8e776a9bc - rustc_query_system[5cd5da38e1781535]::query::plumbing::execute_job_non_incr::<rustc_query_impl[d1b11ab99dd699c5]::queries::typeck, rustc_query_impl[d1b11ab99dd699c5]::plumbing::QueryCtxt>
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_query_system/src/query/plumbing.rs:464:18
  64:     0x7fc8e776a9bc - rustc_query_system[5cd5da38e1781535]::query::plumbing::execute_job::<rustc_query_impl[d1b11ab99dd699c5]::queries::typeck, rustc_query_impl[d1b11ab99dd699c5]::plumbing::QueryCtxt>
                               at /home/matthias/vcs/github/rust_debug_assertions/compiler/rustc_query_system/src/query/plumbing.rs:402:17
.....

[Ezrashaw]

There might be a separate issue here about the "function" arguments. cc @estebank this might've regressed slightly in #106347. More work is definitely needed here (I'll have a go at this after the &mut stuff I think).

EDIT: this is a truly wonderful suggestion: #[derive(Clon, U);.

[estebank]

We really need to land #109082 :-/