ICE Unexpected unnameable type in variance computation #148488
Description
auto-reduced (treereduce-rust):
//@compile-flags: -Zincremental-verify-ich=yes -Cincremental=<dir> -Cdebuginfo=2 -Clink-dead-code=true -Zvalidate-mir -Zquery-dep-graph -Zthreads=4 --edition=2024
pub struct T<'g>()
pub fn ord<a>() -> _ {
async || {
}
}original:
pub struct T<'g>()
pub fn g(val T) {}
pub fn ord<a>() -> _ {
async || {
use std::ptr::null;
use std::task::{RawWaker, RawWakerVTable};
RawWaker::new(
null(),
&RawWakerVTable::new(|_| todo!(), |_| (), |_| (), |_| ()),
);
}
}Version information
rustc 1.93.0-nightly (e5efc3367 2025-11-04)
binary: rustc
commit-hash: e5efc336720901420a8891dcdb67ca0a475dc03c
commit-date: 2025-11-04
host: x86_64-unknown-linux-gnu
release: 1.93.0-nightly
LLVM version: 21.1.3
Possibly related line of code:
rust/compiler/rustc_hir_analysis/src/variance/constraints.rs
Lines 234 to 246 in e5efc33
Command:
/home/matthias/.rustup/toolchains/master/bin/rustc -Zincremental-verify-ich=yes -Cincremental=<dir> -Cdebuginfo=2 -Clink-dead-code=true -Zvalidate-mir -Zquery-dep-graph -Zthreads=4 --edition=2024
Program output
error: expected `;`, found keyword `pub`
--> /tmp/icemaker_global_tempdir.gzW1Q91qvivC/rustc_testrunner_tmpdir_reporting.nmuBTsFqUqAM/mvce.rs:1:19
|
1 | pub struct T<'g>()
| ^ help: add `;` here
...
5 | pub fn ord<a>() -> _ {
| --- unexpected token
warning: type parameter `a` should have an upper camel case name
--> /tmp/icemaker_global_tempdir.gzW1Q91qvivC/rustc_testrunner_tmpdir_reporting.nmuBTsFqUqAM/mvce.rs:5:12
|
5 | pub fn ord<a>() -> _ {
| ^ help: convert the identifier to upper camel case: `A`
|
= note: `#[warn(non_camel_case_types)]` (part of `#[warn(nonstandard_style)]`) on by default
error[E0601]: `main` function not found in crate `mvce`
--> /tmp/icemaker_global_tempdir.gzW1Q91qvivC/rustc_testrunner_tmpdir_reporting.nmuBTsFqUqAM/mvce.rs:11:2
|
11 | }
| ^ consider adding a `main` function to `/tmp/icemaker_global_tempdir.gzW1Q91qvivC/rustc_testrunner_tmpdir_reporting.nmuBTsFqUqAM/mvce.rs`
error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
--> /tmp/icemaker_global_tempdir.gzW1Q91qvivC/rustc_testrunner_tmpdir_reporting.nmuBTsFqUqAM/mvce.rs:5:20
|
5 | pub fn ord<a>() -> _ {
| ^ not allowed in type signatures
|
help: replace with the correct return type
|
5 - pub fn ord<a>() -> _ {
5 + pub fn ord<a>() -> {async closure@/tmp/icemaker_global_tempdir.gzW1Q91qvivC/rustc_testrunner_tmpdir_reporting.nmuBTsFqUqAM/mvce.rs:6:5: 6:13} {
|
error: internal compiler error: compiler/rustc_hir_analysis/src/variance/constraints.rs:240:17: Unexpected unnameable type in variance computation: {async closure@/tmp/icemaker_global_tempdir.gzW1Q91qvivC/rustc_testrunner_tmpdir_reporting.nmuBTsFqUqAM/mvce.rs:6:5: 6:13}
thread 'rustc' (1942480) panicked at compiler/rustc_hir_analysis/src/variance/constraints.rs:240:17:
Box<dyn Any>
stack backtrace:
0: 0x7f5641054dc3 - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::ha3843b722cb6c079
1: 0x7f5641801afc - core::fmt::write::h4cf6c21e30d6fd2c
2: 0x7f5641009903 - std::io::Write::write_fmt::h4fff68ee9517b956
3: 0x7f564101af42 - std::sys::backtrace::BacktraceLock::print::he78023a1ddfd64ff
4: 0x7f5641020f99 - std::panicking::default_hook::{{closure}}::h687012e2f8493e05
5: 0x7f5641020ac3 - std::panicking::default_hook::h49a3243e28fcd9d0
6: 0x7f5640028c61 - std[e5386f4e1d083f30]::panicking::update_hook::<alloc[73bcea237dbcc3ca]::boxed::Box<rustc_driver_impl[738a289c0901248e]::install_ice_hook::{closure#1}>>::{closure#0}
7: 0x7f56410213bf - std::panicking::panic_with_hook::hd8e4eb00c63c2672
8: 0x7f5640065081 - std[e5386f4e1d083f30]::panicking::begin_panic::<rustc_errors[637030874c9f4630]::ExplicitBug>::{closure#0}
9: 0x7f56400573f6 - std[e5386f4e1d083f30]::sys::backtrace::__rust_end_short_backtrace::<std[e5386f4e1d083f30]::panicking::begin_panic<rustc_errors[637030874c9f4630]::ExplicitBug>::{closure#0}, !>
10: 0x7f5640057035 - std[e5386f4e1d083f30]::panicking::begin_panic::<rustc_errors[637030874c9f4630]::ExplicitBug>
11: 0x7f5640076401 - <rustc_errors[637030874c9f4630]::diagnostic::BugAbort as rustc_errors[637030874c9f4630]::diagnostic::EmissionGuarantee>::emit_producing_guarantee
12: 0x7f56405fcb1a - rustc_middle[75169061f14a0aad]::util::bug::opt_span_bug_fmt::<rustc_span[7dee8b18e8817fc5]::span_encoding::Span>::{closure#0}
13: 0x7f56405fcdfa - rustc_middle[75169061f14a0aad]::ty::context::tls::with_opt::<rustc_middle[75169061f14a0aad]::util::bug::opt_span_bug_fmt<rustc_span[7dee8b18e8817fc5]::span_encoding::Span>::{closure#0}, !>::{closure#0}
14: 0x7f56405edbfb - rustc_middle[75169061f14a0aad]::ty::context::tls::with_context_opt::<rustc_middle[75169061f14a0aad]::ty::context::tls::with_opt<rustc_middle[75169061f14a0aad]::util::bug::opt_span_bug_fmt<rustc_span[7dee8b18e8817fc5]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
15: 0x7f563e3425f0 - rustc_middle[75169061f14a0aad]::util::bug::bug_fmt
16: 0x7f564225b950 - <rustc_hir_analysis[630917c900e5f64f]::variance::constraints::ConstraintContext>::add_constraints_from_ty
17: 0x7f564225a579 - <rustc_hir_analysis[630917c900e5f64f]::variance::constraints::ConstraintContext>::build_constraints_for_item
18: 0x7f563e813aed - rustc_hir_analysis[630917c900e5f64f]::variance::crate_variances
19: 0x7f56427f9ce0 - rustc_query_impl[65b9d326d94058ea]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[65b9d326d94058ea]::query_impl::crate_variances::dynamic_query::{closure#2}::{closure#0}, rustc_middle[75169061f14a0aad]::query::erase::Erased<[u8; 8usize]>>
20: 0x7f5642c17e2b - rustc_query_system[90325ef1b104597f]::query::plumbing::try_execute_query::<rustc_query_impl[65b9d326d94058ea]::DynamicConfig<rustc_query_system[90325ef1b104597f]::query::caches::SingleCache<rustc_middle[75169061f14a0aad]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[65b9d326d94058ea]::plumbing::QueryCtxt, true>
21: 0x7f5642c18e85 - rustc_query_impl[65b9d326d94058ea]::query_impl::crate_variances::get_query_incr::__rust_end_short_backtrace
22: 0x7f564193b10d - rustc_query_impl[65b9d326d94058ea]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[65b9d326d94058ea]::query_impl::variances_of::dynamic_query::{closure#2}::{closure#0}, rustc_middle[75169061f14a0aad]::query::erase::Erased<[u8; 16usize]>>
23: 0x7f56422a2c96 - rustc_query_system[90325ef1b104597f]::query::plumbing::try_execute_query::<rustc_query_impl[65b9d326d94058ea]::DynamicConfig<rustc_query_system[90325ef1b104597f]::query::caches::DefIdCache<rustc_middle[75169061f14a0aad]::query::erase::Erased<[u8; 16usize]>>, false, false, false>, rustc_query_impl[65b9d326d94058ea]::plumbing::QueryCtxt, true>
24: 0x7f56422a1988 - rustc_query_impl[65b9d326d94058ea]::query_impl::variances_of::get_query_incr::__rust_end_short_backtrace
25: 0x7f5642220672 - rustc_hir_analysis[630917c900e5f64f]::check::wfcheck::check_variances_for_type_defn
26: 0x7f5642089fae - rustc_hir_analysis[630917c900e5f64f]::check::check::check_item_type
27: 0x7f564208469c - rustc_hir_analysis[630917c900e5f64f]::check::wfcheck::check_well_formed
28: 0x7f5642084675 - rustc_query_impl[65b9d326d94058ea]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[65b9d326d94058ea]::query_impl::check_well_formed::dynamic_query::{closure#2}::{closure#0}, rustc_middle[75169061f14a0aad]::query::erase::Erased<[u8; 1usize]>>
29: 0x7f5641bc7aa1 - rustc_query_system[90325ef1b104597f]::query::plumbing::try_execute_query::<rustc_query_impl[65b9d326d94058ea]::DynamicConfig<rustc_data_structures[716369fb9beee067]::vec_cache::VecCache<rustc_span[7dee8b18e8817fc5]::def_id::LocalDefId, rustc_middle[75169061f14a0aad]::query::erase::Erased<[u8; 1usize]>, rustc_query_system[90325ef1b104597f]::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl[65b9d326d94058ea]::plumbing::QueryCtxt, true>
30: 0x7f5641bca26d - rustc_query_impl[65b9d326d94058ea]::query_impl::check_well_formed::get_query_incr::__rust_end_short_backtrace
31: 0x7f56401490fb - rustc_middle[75169061f14a0aad]::query::inner::query_ensure_error_guaranteed::<rustc_data_structures[716369fb9beee067]::vec_cache::VecCache<rustc_span[7dee8b18e8817fc5]::def_id::LocalDefId, rustc_middle[75169061f14a0aad]::query::erase::Erased<[u8; 1usize]>, rustc_query_system[90325ef1b104597f]::dep_graph::graph::DepNodeIndex>, ()>
32: 0x7f564015645e - rustc_data_structures[716369fb9beee067]::sync::parallel::par_slice::par_rec::<&rustc_hir[71709be17c67fcbd]::hir::ItemId, rustc_data_structures[716369fb9beee067]::sync::parallel::try_par_for_each_in<&[rustc_hir[71709be17c67fcbd]::hir::ItemId], rustc_span[7dee8b18e8817fc5]::ErrorGuaranteed, <rustc_middle[75169061f14a0aad]::hir::ModuleItems>::par_items<rustc_hir_analysis[630917c900e5f64f]::check::wfcheck::check_type_wf::{closure#0}>::{closure#0}>::{closure#0}::{closure#0}>
33: 0x7f564018f617 - rustc_thread_pool[67e4e2991aa033df]::join::join_context::<rustc_thread_pool[67e4e2991aa033df]::join::join::call<(), rustc_data_structures[716369fb9beee067]::sync::parallel::par_slice::par_rec<&rustc_hir[71709be17c67fcbd]::hir::ItemId, rustc_data_structures[716369fb9beee067]::sync::parallel::try_par_for_each_in<&[rustc_hir[71709be17c67fcbd]::hir::ItemId], rustc_span[7dee8b18e8817fc5]::ErrorGuaranteed, <rustc_middle[75169061f14a0aad]::hir::ModuleItems>::par_items<rustc_hir_analysis[630917c900e5f64f]::check::wfcheck::check_type_wf::{closure#0}>::{closure#0}>::{closure#0}::{closure#0}>::{closure#1}>::{closure#0}, rustc_thread_pool[67e4e2991aa033df]::join::join::call<(), rustc_data_structures[716369fb9beee067]::sync::parallel::par_slice::par_rec<&rustc_hir[71709be17c67fcbd]::hir::ItemId, rustc_data_structures[716369fb9beee067]::sync::parallel::try_par_for_each_in<&[rustc_hir[71709be17c67fcbd]::hir::ItemId], rustc_span[7dee8b18e8817fc5]::ErrorGuaranteed, <rustc_middle[75169061f14a0aad]::hir::ModuleItems>::par_items<rustc_hir_analysis[630917c900e5f64f]::check::wfcheck::check_type_wf::{closure#0}>::{closure#0}>::{closure#0}::{closure#0}>::{closure#2}>::{closure#0}, (), ()>::{closure#0}
34: 0x7f5640156505 - rustc_data_structures[716369fb9beee067]::sync::parallel::par_slice::par_rec::<&rustc_hir[71709be17c67fcbd]::hir::ItemId, rustc_data_structures[716369fb9beee067]::sync::parallel::try_par_for_each_in<&[rustc_hir[71709be17c67fcbd]::hir::ItemId], rustc_span[7dee8b18e8817fc5]::ErrorGuaranteed, <rustc_middle[75169061f14a0aad]::hir::ModuleItems>::par_items<rustc_hir_analysis[630917c900e5f64f]::check::wfcheck::check_type_wf::{closure#0}>::{closure#0}>::{closure#0}::{closure#0}>
35: 0x7f5640218757 - <rustc_thread_pool[67e4e2991aa033df]::job::StackJob<rustc_thread_pool[67e4e2991aa033df]::latch::SpinLatch, rustc_thread_pool[67e4e2991aa033df]::join::join_context<rustc_thread_pool[67e4e2991aa033df]::join::join::call<(), rustc_data_structures[716369fb9beee067]::sync::parallel::par_slice::par_rec<&rustc_hir[71709be17c67fcbd]::hir::ItemId, rustc_data_structures[716369fb9beee067]::sync::parallel::try_par_for_each_in<&[rustc_hir[71709be17c67fcbd]::hir::ItemId], rustc_span[7dee8b18e8817fc5]::ErrorGuaranteed, <rustc_middle[75169061f14a0aad]::hir::ModuleItems>::par_items<rustc_hir_analysis[630917c900e5f64f]::check::wfcheck::check_type_wf::{closure#0}>::{closure#0}>::{closure#0}::{closure#0}>::{closure#1}>::{closure#0}, rustc_thread_pool[67e4e2991aa033df]::join::join::call<(), rustc_data_structures[716369fb9beee067]::sync::parallel::par_slice::par_rec<&rustc_hir[71709be17c67fcbd]::hir::ItemId, rustc_data_structures[716369fb9beee067]::sync::parallel::try_par_for_each_in<&[rustc_hir[71709be17c67fcbd]::hir::ItemId], rustc_span[7dee8b18e8817fc5]::ErrorGuaranteed, <rustc_middle[75169061f14a0aad]::hir::ModuleItems>::par_items<rustc_hir_analysis[630917c900e5f64f]::check::wfcheck::check_type_wf::{closure#0}>::{closure#0}>::{closure#0}::{closure#0}>::{closure#2}>::{closure#0}, (), ()>::{closure#0}::{closure#0}, ()> as rustc_thread_pool[67e4e2991aa033df]::job::Job>::execute
36: 0x7f5640d2b53f - <rustc_thread_pool[67e4e2991aa033df]::registry::WorkerThread>::wait_or_steal_until_cold
37: 0x7f5640d29e81 - <rustc_thread_pool[67e4e2991aa033df]::registry::ThreadBuilder>::run
38: 0x7f5640020c8d - std[e5386f4e1d083f30]::sys::backtrace::__rust_begin_short_backtrace::<<rustc_thread_pool[67e4e2991aa033df]::ThreadPoolBuilder>::build_scoped<rustc_interface[bd0f1886b04bcc2f]::util::run_in_thread_pool_with_globals<rustc_interface[bd0f1886b04bcc2f]::interface::run_compiler<(), rustc_driver_impl[738a289c0901248e]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#5}::{closure#0}::{closure#0}, rustc_interface[bd0f1886b04bcc2f]::util::run_in_thread_pool_with_globals<rustc_interface[bd0f1886b04bcc2f]::interface::run_compiler<(), rustc_driver_impl[738a289c0901248e]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#5}::{closure#0}::{closure#1}, ()>::{closure#0}::{closure#0}::{closure#0}, ()>
39: 0x7f564002bc52 - <<std[e5386f4e1d083f30]::thread::Builder>::spawn_unchecked_<<rustc_thread_pool[67e4e2991aa033df]::ThreadPoolBuilder>::build_scoped<rustc_interface[bd0f1886b04bcc2f]::util::run_in_thread_pool_with_globals<rustc_interface[bd0f1886b04bcc2f]::interface::run_compiler<(), rustc_driver_impl[738a289c0901248e]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#5}::{closure#0}::{closure#0}, rustc_interface[bd0f1886b04bcc2f]::util::run_in_thread_pool_with_globals<rustc_interface[bd0f1886b04bcc2f]::interface::run_compiler<(), rustc_driver_impl[738a289c0901248e]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#5}::{closure#0}::{closure#1}, ()>::{closure#0}::{closure#0}::{closure#0}, ()>::{closure#1} as core[74e9d517ffeea944]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
40: 0x7f564269fc6f - std::sys::thread::unix::Thread::new::thread_start::h7bfb9de84f244c7c
41: 0x7f563c0969cb - <unknown>
42: 0x7f563c11aa0c - <unknown>
43: 0x0 - <unknown>
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 1.93.0-nightly (e5efc3367 2025-11-04) running on x86_64-unknown-linux-gnu
note: compiler flags: -Z incremental-verify-ich=yes -C incremental=[REDACTED] -C debuginfo=2 -C link-dead-code=true -Z validate-mir -Z query-dep-graph -Z threads=4
query stack during panic:
#0 [crate_variances] computing the variances for items in this crate
#1 [variances_of] computing the variances of `T`
#2 [check_well_formed] checking that `T` is well-formed
#3 [check_type_wf] checking that types are well-formed
#4 [analysis] running analysis passes on crate `mvce`
end of query stack
error: aborting due to 4 previous errors; 1 warning emitted
Some errors have detailed explanations: E0121, E0601.
For more information about an error, try `rustc --explain E0121`.