ICE: incr comp: Span must not be empty and have no suggestion #149559
Description
Code
struct Foo<T>;
macro_rules! foo_ty {
($a:ty, $b:ty) => {
Foo<a, $b>
}
}
fn foo<'a, 'b>() -> foo_ty!(&'b (), &'b ()) {}
fn main() {}Meta
rustc --version --verbose:
rustc 1.93.0-nightly (63b1db058 2025-12-02)
binary: rustc
commit-hash: 63b1db05801271e400954e41b8600a3cf1482363
commit-date: 2025-12-02
host: x86_64-unknown-linux-gnu
release: 1.93.0-nightly
LLVM version: 21.1.5
required debug assertions, only reproducible with incr comp (don't ask why..)
rustc code.rs -Cincremental=.
Error output
error[E0412]: cannot find type `a` in this scope
--> code.rs:5:13
|
5 | Foo<a, $b>
| ^ not found in this scope
...
8 | fn foo<'a, 'b>() -> foo_ty!(&'b (), &'b ()) {}
| ----------------------- in this macro invocation
|
= note: this error originates in the macro `foo_ty` (in Nightly builds, run with -Z macro-backtrace for more info)
help: you might be missing a type parameter
|
8 | fn foo<'a, 'b, a>() -> foo_ty!(&'b (), &'b ()) {}
| +++
Backtrace
thread 'rustc' (3343042) panicked at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/compiler/rustc_errors/src/diagnostic.rs:1030:9:
Span must not be empty and have no suggestion
stack backtrace:
0: 0x7f3f3594bd80 - std[bebcfa26ff680867]::backtrace_rs::backtrace::libunwind::trace
at /rustc/63b1db05801271e400954e41b8600a3cf1482363/library/std/src/../../backtrace/src/backtrace/libunwind.rs:117:9
1: 0x7f3f3594bd80 - std[bebcfa26ff680867]::backtrace_rs::backtrace::trace_unsynchronized::<std[bebcfa26ff680867]::sys::backtrace::_print_fmt::{closure#1}>
at /rustc/63b1db05801271e400954e41b8600a3cf1482363/library/std/src/../../backtrace/src/backtrace/mod.rs:66:14
2: 0x7f3f3594bd80 - std[bebcfa26ff680867]::sys::backtrace::_print_fmt
at /rustc/63b1db05801271e400954e41b8600a3cf1482363/library/std/src/sys/backtrace.rs:68:9
3: 0x7f3f3594bd80 - <<std[bebcfa26ff680867]::sys::backtrace::BacktraceLock>::print::DisplayBacktrace as core[91c473b3610db379]::fmt::Display>::fmt
at /rustc/63b1db05801271e400954e41b8600a3cf1482363/library/std/src/sys/backtrace.rs:38:26
4: 0x7f3f3131fa2e - <core[91c473b3610db379]::fmt::rt::Argument>::fmt
at /rustc/63b1db05801271e400954e41b8600a3cf1482363/library/core/src/fmt/rt.rs:152:76
5: 0x7f3f3131fa2e - core[91c473b3610db379]::fmt::write
6: 0x7f3f35964b4c - std[bebcfa26ff680867]::io::default_write_fmt::<std[bebcfa26ff680867]::sys::stdio::unix::Stderr>
at /rustc/63b1db05801271e400954e41b8600a3cf1482363/library/std/src/io/mod.rs:639:11
7: 0x7f3f35964b4c - <std[bebcfa26ff680867]::sys::stdio::unix::Stderr as std[bebcfa26ff680867]::io::Write>::write_fmt
at /rustc/63b1db05801271e400954e41b8600a3cf1482363/library/std/src/io/mod.rs:1994:13
8: 0x7f3f3590dc86 - <std[bebcfa26ff680867]::sys::backtrace::BacktraceLock>::print
at /rustc/63b1db05801271e400954e41b8600a3cf1482363/library/std/src/sys/backtrace.rs:41:9
9: 0x7f3f3590dc86 - std[bebcfa26ff680867]::panicking::default_hook::{closure#0}
at /rustc/63b1db05801271e400954e41b8600a3cf1482363/library/std/src/panicking.rs:292:27
10: 0x7f3f35937221 - std[bebcfa26ff680867]::panicking::default_hook
at /rustc/63b1db05801271e400954e41b8600a3cf1482363/library/std/src/panicking.rs:319:9
11: 0x7f3f32562814 - <alloc[a8d04eb2314326e5]::boxed::Box<dyn for<'a, 'b> core[91c473b3610db379]::ops::function::Fn<(&'a std[bebcfa26ff680867]::panic::PanicHookInfo<'b>,), Output = ()> + core[91c473b3610db379]::marker::Send + core[91c473b3610db379]::marker::Sync> as core[91c473b3610db379]::ops::function::Fn<(&std[bebcfa26ff680867]::panic::PanicHookInfo,)>>::call
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/library/alloc/src/boxed.rs:2220:9
12: 0x7f3f32562814 - rustc_driver_impl[13cf1191ca3affe6]::install_ice_hook::{closure#1}
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/compiler/rustc_driver_impl/src/lib.rs:1432:17
13: 0x7f3f32562814 - <alloc[a8d04eb2314326e5]::boxed::Box<rustc_driver_impl[13cf1191ca3affe6]::install_ice_hook::{closure#1}> as core[91c473b3610db379]::ops::function::Fn<(&dyn for<'a, 'b> core[91c473b3610db379]::ops::function::Fn<(&'a std[bebcfa26ff680867]::panic::PanicHookInfo<'b>,), Output = ()> + core[91c473b3610db379]::marker::Send + core[91c473b3610db379]::marker::Sync, &std[bebcfa26ff680867]::panic::PanicHookInfo)>>::call
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/library/alloc/src/boxed.rs:2220:9
14: 0x7f3f32562814 - std[bebcfa26ff680867]::panicking::update_hook::<alloc[a8d04eb2314326e5]::boxed::Box<rustc_driver_impl[13cf1191ca3affe6]::install_ice_hook::{closure#1}>>::{closure#0}
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/library/std/src/panicking.rs:235:47
15: 0x7f3f359375b1 - <alloc[a8d04eb2314326e5]::boxed::Box<dyn for<'a, 'b> core[91c473b3610db379]::ops::function::Fn<(&'a std[bebcfa26ff680867]::panic::PanicHookInfo<'b>,), Output = ()> + core[91c473b3610db379]::marker::Send + core[91c473b3610db379]::marker::Sync> as core[91c473b3610db379]::ops::function::Fn<(&std[bebcfa26ff680867]::panic::PanicHookInfo,)>>::call
at /rustc/63b1db05801271e400954e41b8600a3cf1482363/library/alloc/src/boxed.rs:2220:9
16: 0x7f3f359375b1 - std[bebcfa26ff680867]::panicking::panic_with_hook
at /rustc/63b1db05801271e400954e41b8600a3cf1482363/library/std/src/panicking.rs:833:13
17: 0x7f3f3590dd7c - std[bebcfa26ff680867]::panicking::panic_handler::{closure#0}
at /rustc/63b1db05801271e400954e41b8600a3cf1482363/library/std/src/panicking.rs:691:13
18: 0x7f3f358fce89 - std[bebcfa26ff680867]::sys::backtrace::__rust_end_short_backtrace::<std[bebcfa26ff680867]::panicking::panic_handler::{closure#0}, !>
at /rustc/63b1db05801271e400954e41b8600a3cf1482363/library/std/src/sys/backtrace.rs:176:18
19: 0x7f3f3590ff6d - __rustc[9f2c982343335ef0]::rust_begin_unwind
at /rustc/63b1db05801271e400954e41b8600a3cf1482363/library/std/src/panicking.rs:689:5
20: 0x7f3f313203ec - core[91c473b3610db379]::panicking::panic_fmt
at /rustc/63b1db05801271e400954e41b8600a3cf1482363/library/core/src/panicking.rs:80:14
21: 0x7f3f328957de - <rustc_errors[63a492c13094a53e]::diagnostic::Diag>::span_suggestion_with_style::<alloc[a8d04eb2314326e5]::string::String, &str>
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/compiler/rustc_errors/src/diagnostic.rs:1030:9
22: 0x7f3f32c2a24b - <rustc_errors[63a492c13094a53e]::diagnostic::Diag>::span_suggestion::<alloc[a8d04eb2314326e5]::string::String, &str>
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/compiler/rustc_errors/src/diagnostic.rs:1010:14
23: 0x7f3f32c2a24b - <rustc_hir_analysis[6b4a97736fbac468]::errors::wrong_number_of_generic_args::WrongNumberOfGenericArgs>::suggest_removing_args_or_generics::<rustc_span[bfa6808a5e92da49]::ErrorGuaranteed>::{closure#1}
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/compiler/rustc_hir_analysis/src/errors/wrong_number_of_generic_args.rs:1005:17
24: 0x7f3f32c2a24b - <rustc_hir_analysis[6b4a97736fbac468]::errors::wrong_number_of_generic_args::WrongNumberOfGenericArgs>::suggest_removing_args_or_generics::<rustc_span[bfa6808a5e92da49]::ErrorGuaranteed>
25: 0x7f3f32c2a24b - <rustc_hir_analysis[6b4a97736fbac468]::errors::wrong_number_of_generic_args::WrongNumberOfGenericArgs>::suggest::<rustc_span[bfa6808a5e92da49]::ErrorGuaranteed>
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/compiler/rustc_hir_analysis/src/errors/wrong_number_of_generic_args.rs:615:26
26: 0x7f3f32c2a24b - <rustc_hir_analysis[6b4a97736fbac468]::errors::wrong_number_of_generic_args::WrongNumberOfGenericArgs as rustc_errors[63a492c13094a53e]::diagnostic::Diagnostic>::into_diag
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/compiler/rustc_hir_analysis/src/errors/wrong_number_of_generic_args.rs:1151:14
27: 0x7f3f32ac451c - <rustc_errors[63a492c13094a53e]::DiagCtxtHandle>::create_err::<rustc_hir_analysis[6b4a97736fbac468]::errors::wrong_number_of_generic_args::WrongNumberOfGenericArgs>
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/compiler/rustc_errors/src/lib.rs:1361:13
28: 0x7f3f32ac451c - rustc_hir_analysis[6b4a97736fbac468]::hir_ty_lowering::generics::check_generic_arg_count::{closure#2}::{closure#5}
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/compiler/rustc_hir_analysis/src/hir_ty_lowering/generics.rs:557:18
29: 0x7f3f32ac451c - <core[91c473b3610db379]::option::Option<rustc_span[bfa6808a5e92da49]::ErrorGuaranteed>>::unwrap_or_else::<rustc_hir_analysis[6b4a97736fbac468]::hir_ty_lowering::generics::check_generic_arg_count::{closure#2}::{closure#5}>
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/library/core/src/option.rs:1067:21
30: 0x7f3f32ac451c - rustc_hir_analysis[6b4a97736fbac468]::hir_ty_lowering::generics::check_generic_arg_count::{closure#2}
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/compiler/rustc_hir_analysis/src/hir_ty_lowering/generics.rs:555:43
31: 0x7f3f32ac451c - rustc_hir_analysis[6b4a97736fbac468]::hir_ty_lowering::generics::check_generic_arg_count
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/compiler/rustc_hir_analysis/src/hir_ty_lowering/generics.rs:585:9
32: 0x7f3f32a2eb47 - <dyn rustc_hir_analysis[6b4a97736fbac468]::hir_ty_lowering::HirTyLowerer>::lower_generic_args_of_path::{closure#0}
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs:527:25
33: 0x7f3f32a2eb47 - <dyn rustc_hir_analysis[6b4a97736fbac468]::hir_ty_lowering::HirTyLowerer>::lower_generic_args_of_path
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs:497:5
34: 0x7f3f32a191e2 - <dyn rustc_hir_analysis[6b4a97736fbac468]::hir_ty_lowering::HirTyLowerer>::lower_generic_args_of_path_segment
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs:456:30
35: 0x7f3f32a191e2 - <dyn rustc_hir_analysis[6b4a97736fbac468]::hir_ty_lowering::HirTyLowerer>::lower_path_segment
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs:1033:25
36: 0x7f3f32a277e9 - <dyn rustc_hir_analysis[6b4a97736fbac468]::hir_ty_lowering::HirTyLowerer>::lower_resolved_ty_path
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs:1991:22
37: 0x7f3f32a3ab8e - <dyn rustc_hir_analysis[6b4a97736fbac468]::hir_ty_lowering::HirTyLowerer>::lower_ty::{closure#0}
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs:2503:22
38: 0x7f3f32a3ab8e - <dyn rustc_hir_analysis[6b4a97736fbac468]::hir_ty_lowering::HirTyLowerer>::lower_ty
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs:2451:5
39: 0x7f3f32ba473c - <rustc_hir_analysis[6b4a97736fbac468]::collect::ItemCtxt>::lower_ty
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/compiler/rustc_hir_analysis/src/collect.rs:251:24
40: 0x7f3f32ba473c - <rustc_hir_analysis[6b4a97736fbac468]::collect::ItemCtxt as rustc_hir_analysis[6b4a97736fbac468]::hir_ty_lowering::HirTyLowerer>::lower_fn_sig
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/compiler/rustc_hir_analysis/src/collect.rs:555:26
41: 0x7f3f32a0efbc - <dyn rustc_hir_analysis[6b4a97736fbac468]::hir_ty_lowering::HirTyLowerer>::lower_fn_ty::{closure#0}
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs:2708:43
42: 0x7f3f32a0efbc - <dyn rustc_hir_analysis[6b4a97736fbac468]::hir_ty_lowering::HirTyLowerer>::lower_fn_ty
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs:2694:5
43: 0x7f3f32aa9981 - rustc_hir_analysis[6b4a97736fbac468]::collect::fn_sig::{closure#0}
44: 0x7f3f32aa9981 - rustc_hir_analysis[6b4a97736fbac468]::collect::fn_sig
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/compiler/rustc_hir_analysis/src/collect.rs:1019:1
45: 0x7f3f34719cd5 - rustc_query_impl[23cc7eb0a608f334]::query_impl::fn_sig::dynamic_query::{closure#2}::{closure#0}
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/compiler/rustc_query_impl/src/plumbing.rs:302:13
46: 0x7f3f34719cd5 - rustc_query_impl[23cc7eb0a608f334]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[23cc7eb0a608f334]::query_impl::fn_sig::dynamic_query::{closure#2}::{closure#0}, rustc_middle[f63169c9694c4243]::query::erase::Erased<[u8; 24usize]>>
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/compiler/rustc_query_impl/src/plumbing.rs:582:18
47: 0x7f3f34b7a879 - rustc_query_impl[23cc7eb0a608f334]::query_impl::fn_sig::dynamic_query::{closure#2}
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/compiler/rustc_query_impl/src/plumbing.rs:659:25
48: 0x7f3f34b7a879 - <rustc_query_impl[23cc7eb0a608f334]::query_impl::fn_sig::dynamic_query::{closure#2} as core[91c473b3610db379]::ops::function::FnOnce<(rustc_middle[f63169c9694c4243]::ty::context::TyCtxt, rustc_span[bfa6808a5e92da49]::def_id::DefId)>>::call_once
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/library/core/src/ops/function.rs:250:5
49: 0x7f3f34766f7a - <rustc_query_impl[23cc7eb0a608f334]::DynamicConfig<rustc_query_system[db29a4a82fe48170]::query::caches::DefIdCache<rustc_middle[f63169c9694c4243]::query::erase::Erased<[u8; 24usize]>>, false, false, false> as rustc_query_system[db29a4a82fe48170]::query::config::QueryConfig<rustc_query_impl[23cc7eb0a608f334]::plumbing::QueryCtxt>>::compute
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/compiler/rustc_query_impl/src/lib.rs:119:9
50: 0x7f3f34766f7a - rustc_query_system[db29a4a82fe48170]::query::plumbing::execute_job_incr::<rustc_query_impl[23cc7eb0a608f334]::DynamicConfig<rustc_query_system[db29a4a82fe48170]::query::caches::DefIdCache<rustc_middle[f63169c9694c4243]::query::erase::Erased<[u8; 24usize]>>, false, false, false>, rustc_query_impl[23cc7eb0a608f334]::plumbing::QueryCtxt>::{closure#2}::{closure#2}
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/compiler/rustc_query_system/src/query/plumbing.rs:569:39
51: 0x7f3f34766f7a - <rustc_query_system[db29a4a82fe48170]::query::plumbing::execute_job_incr<rustc_query_impl[23cc7eb0a608f334]::DynamicConfig<rustc_query_system[db29a4a82fe48170]::query::caches::DefIdCache<rustc_middle[f63169c9694c4243]::query::erase::Erased<[u8; 24usize]>>, false, false, false>, rustc_query_impl[23cc7eb0a608f334]::plumbing::QueryCtxt>::{closure#2}::{closure#2} as core[91c473b3610db379]::ops::function::FnOnce<((rustc_query_impl[23cc7eb0a608f334]::plumbing::QueryCtxt, rustc_query_impl[23cc7eb0a608f334]::DynamicConfig<rustc_query_system[db29a4a82fe48170]::query::caches::DefIdCache<rustc_middle[f63169c9694c4243]::query::erase::Erased<[u8; 24usize]>>, false, false, false>), rustc_span[bfa6808a5e92da49]::def_id::DefId)>>::call_once
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/library/core/src/ops/function.rs:250:5
52: 0x7f3f34766f7a - <rustc_query_system[db29a4a82fe48170]::dep_graph::graph::DepGraphData<rustc_middle[f63169c9694c4243]::dep_graph::DepsType>>::with_task::<(rustc_query_impl[23cc7eb0a608f334]::plumbing::QueryCtxt, rustc_query_impl[23cc7eb0a608f334]::DynamicConfig<rustc_query_system[db29a4a82fe48170]::query::caches::DefIdCache<rustc_middle[f63169c9694c4243]::query::erase::Erased<[u8; 24usize]>>, false, false, false>), rustc_span[bfa6808a5e92da49]::def_id::DefId, rustc_middle[f63169c9694c4243]::query::erase::Erased<[u8; 24usize]>>::{closure#1}::{closure#0}
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/compiler/rustc_query_system/src/dep_graph/graph.rs:338:64
53: 0x7f3f34766f7a - rustc_middle[f63169c9694c4243]::ty::context::tls::enter_context::<<rustc_query_system[db29a4a82fe48170]::dep_graph::graph::DepGraphData<rustc_middle[f63169c9694c4243]::dep_graph::DepsType>>::with_task<(rustc_query_impl[23cc7eb0a608f334]::plumbing::QueryCtxt, rustc_query_impl[23cc7eb0a608f334]::DynamicConfig<rustc_query_system[db29a4a82fe48170]::query::caches::DefIdCache<rustc_middle[f63169c9694c4243]::query::erase::Erased<[u8; 24usize]>>, false, false, false>), rustc_span[bfa6808a5e92da49]::def_id::DefId, rustc_middle[f63169c9694c4243]::query::erase::Erased<[u8; 24usize]>>::{closure#1}::{closure#0}, rustc_middle[f63169c9694c4243]::query::erase::Erased<[u8; 24usize]>>::{closure#0}
....
....
...
355: 0x7f1a40f714a4 - std[bebcfa26ff680867]::thread::lifecycle::spawn_unchecked::<rustc_interface[c6c376a60685e945]::util::run_in_thread_with_globals<rustc_interface[c6c376a60685e945]::util::run_in_thread_pool_with_globals<rustc_interface[c6c376a60685e945]::interface::run_compiler<(), rustc_driver_impl[13cf1191ca3affe6]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1}
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/library/std/src/thread/lifecycle.rs:90:26
356: 0x7f1a40f714a4 - <std[bebcfa26ff680867]::thread::lifecycle::spawn_unchecked<rustc_interface[c6c376a60685e945]::util::run_in_thread_with_globals<rustc_interface[c6c376a60685e945]::util::run_in_thread_pool_with_globals<rustc_interface[c6c376a60685e945]::interface::run_compiler<(), rustc_driver_impl[13cf1191ca3affe6]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core[91c473b3610db379]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
at /rustc-dev/63b1db05801271e400954e41b8600a3cf1482363/library/core/src/ops/function.rs:250:5
357: 0x7f1a44348b99 - <alloc[a8d04eb2314326e5]::boxed::Box<dyn core[91c473b3610db379]::ops::function::FnOnce<(), Output = ()> + core[91c473b3610db379]::marker::Send> as core[91c473b3610db379]::ops::function::FnOnce<()>>::call_once
at /rustc/63b1db05801271e400954e41b8600a3cf1482363/library/alloc/src/boxed.rs:2206:9
358: 0x7f1a44348b99 - <std[bebcfa26ff680867]::sys::thread::unix::Thread>::new::thread_start
at /rustc/63b1db05801271e400954e41b8600a3cf1482363/library/std/src/sys/thread/unix.rs:119:17
359: 0x7f1a3e2969cb - <unknown>
360: 0x7f1a3e31aa0c - <unknown>
361: 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/matthias/vcs/github/CRED/rustc-ice-2025-12-02T20_39_49-3343166.txt` to your bug report
note: compiler flags: -C incremental=[REDACTED]
query stack during panic:
#0 [fn_sig] computing function signature of `foo`
#1 [crate_variances] computing the variances for items in this crate
... and 4 other queries... use `env RUST_BACKTRACE=1` to see the full query stack
error: aborting due to 1 previous error
For more information about this error, try `rustc --explain E0412`.