ICE: `unexpected bound ty in binder: DefId(0:4 ~ a[bb61]::foo::V)`
Open
Nobody has claimed this yet.
C-bug
F-non_lifetime_binders
F-transmutability
I-ICE
S-has-bisection
S-has-mcve
T-compiler
- Dominant language
- Rust
- Stars
- 119k
- Forks
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Description
auto-reduced (treereduce-rust):
#![feature(non_lifetime_binders)]
fn foo()
where
for<V> V: std::mem::TransmuteFrom<()>,
{
}
original:
#![feature(non_lifetime_binders)]
pub fn foo()
where
for<V> V: std::mem::TransmuteFrom<()>,
{
}
fn main() {
foo();
}
Version information
rustc 1.88.0-nightly (fedf10752 2025-03-30)
binary: rustc
commit-hash: fedf10752b973d83f3f7c0f819b2659c21a634de
commit-date: 2025-03-30
host: x86_64-unknown-linux-gnu
release: 1.88.0-nightly
LLVM version: 20.1.1
Possibly related line of code:
https://github.com/rust-lang/rust/blob/fedf10752b973d83f3f7c0f819b2659c21a634de/compiler/rustc_ty_utils/src/layout.rs#L627-L639
Command:
/home/matthias/.rustup/toolchains/master/bin/rustc
Program output
warning: the feature `non_lifetime_binders` is incomplete and may not be safe to use and/or cause compiler crashes
--> /tmp/icemaker_global_tempdir.DmSZgJbVRSAt/rustc_testrunner_tmpdir_reporting.59tIQJjLPwq7/mvce.rs:1:12
|
1 | #![feature(non_lifetime_binders)]
| ^^^^^^^^^^^^^^^^^^^^
|
= note: see issue #108185 <https://github.com/rust-lang/rust/issues/108185> for more information
= note: `#[warn(incomplete_features)]` on by default
error[E0601]: `main` function not found in crate `mvce`
--> /tmp/icemaker_global_tempdir.DmSZgJbVRSAt/rustc_testrunner_tmpdir_reporting.59tIQJjLPwq7/mvce.rs:7:2
|
7 | }
| ^ consider adding a `main` function to `/tmp/icemaker_global_tempdir.DmSZgJbVRSAt/rustc_testrunner_tmpdir_reporting.59tIQJjLPwq7/mvce.rs`
error[E0658]: use of unstable library feature `transmutability`
--> /tmp/icemaker_global_tempdir.DmSZgJbVRSAt/rustc_testrunner_tmpdir_reporting.59tIQJjLPwq7/mvce.rs:5:15
|
5 | for<V> V: std::mem::TransmuteFrom<()>,
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: see issue #99571 <https://github.com/rust-lang/rust/issues/99571> for more information
= help: add `#![feature(transmutability)]` to the crate attributes to enable
= note: this compiler was built on 2025-03-30; consider upgrading it if it is out of date
error: internal compiler error: compiler/rustc_ty_utils/src/layout.rs:633:13: layout_of: unexpected type `V`
thread 'rustc' panicked at compiler/rustc_ty_utils/src/layout.rs:633:13:
Box<dyn Any>
stack backtrace:
0: 0x72c7aa67c793 - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::h2497ecf60619df83
1: 0x72c7aae05dd1 - core::fmt::write::hf5a66c3f8faccda1
2: 0x72c7ac299291 - std::io::Write::write_fmt::h36dd80397df4cb14
3: 0x72c7aa67c5f2 - std::sys::backtrace::BacktraceLock::print::h0825bf07c4aff9b1
4: 0x72c7aa6800da - std::panicking::default_hook::{{closure}}::he12fe84d83680e45
5: 0x72c7aa67fc5f - std::panicking::default_hook::haaa620bc6350c8d2
6: 0x72c7a96e89b0 - std[bdc4cefc0c032e43]::panicking::update_hook::<alloc[a4260201fb21f0fa]::boxed::Box<rustc_driver_impl[a82370bbe3079b02]::install_ice_hook::{closure#1}>>::{closure#0}
7: 0x72c7aa680953 - std::panicking::rust_panic_with_hook::hfdc1820ccce7abc1
8: 0x72c7a97276c1 - std[bdc4cefc0c032e43]::panicking::begin_panic::<rustc_errors[cfdee618df6c88ef]::ExplicitBug>::{closure#0}
9: 0x72c7a971b386 - std[bdc4cefc0c032e43]::sys::backtrace::__rust_end_short_backtrace::<std[bdc4cefc0c032e43]::panicking::begin_panic<rustc_errors[cfdee618df6c88ef]::ExplicitBug>::{closure#0}, !>
10: 0x72c7a9717edb - std[bdc4cefc0c032e43]::panicking::begin_panic::<rustc_errors[cfdee618df6c88ef]::ExplicitBug>
11: 0x72c7a9730f61 - <rustc_errors[cfdee618df6c88ef]::diagnostic::BugAbort as rustc_errors[cfdee618df6c88ef]::diagnostic::EmissionGuarantee>::emit_producing_guarantee
12: 0x72c7a9d6a3ea - rustc_middle[8c2abaea4e51ae95]::util::bug::opt_span_bug_fmt::<rustc_span[45ddaf2096a5a8e9]::span_encoding::Span>::{closure#0}
13: 0x72c7a9d45e3a - rustc_middle[8c2abaea4e51ae95]::ty::context::tls::with_opt::<rustc_middle[8c2abaea4e51ae95]::util::bug::opt_span_bug_fmt<rustc_span[45ddaf2096a5a8e9]::span_encoding::Span>::{closure#0}, !>::{closure#0}
14: 0x72c7a9d45cab - rustc_middle[8c2abaea4e51ae95]::ty::context::tls::with_context_opt::<rustc_middle[8c2abaea4e51ae95]::ty::context::tls::with_opt<rustc_middle[8c2abaea4e51ae95]::util::bug::opt_span_bug_fmt<rustc_span[45ddaf2096a5a8e9]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
15: 0x72c7a77ac7f0 - rustc_middle[8c2abaea4e51ae95]::util::bug::bug_fmt
16: 0x72c7ab41e1ef - rustc_ty_utils[f05c1afdcf01e29b]::layout::layout_of
17: 0x72c7ab41212a - rustc_query_impl[77fbfc8efa1d0dfd]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[77fbfc8efa1d0dfd]::query_impl::layout_of::dynamic_query::{closure#2}::{closure#0}, rustc_middle[8c2abaea4e51ae95]::query::erase::Erased<[u8; 16usize]>>
18: 0x72c7ab411060 - rustc_query_system[73d5636c4135c7e]::query::plumbing::try_execute_query::<rustc_query_impl[77fbfc8efa1d0dfd]::DynamicConfig<rustc_query_system[73d5636c4135c7e]::query::caches::DefaultCache<rustc_middle[8c2abaea4e51ae95]::ty::PseudoCanonicalInput<rustc_middle[8c2abaea4e51ae95]::ty::Ty>, rustc_middle[8c2abaea4e51ae95]::query::erase::Erased<[u8; 16usize]>>, false, true, false>, rustc_query_impl[77fbfc8efa1d0dfd]::plumbing::QueryCtxt, false>
19: 0x72c7ab410c9e - rustc_query_impl[77fbfc8efa1d0dfd]::query_impl::layout_of::get_query_non_incr::__rust_end_short_backtrace
20: 0x72c7aa5bb5a7 - rustc_transmute[a389da957d26f46d]::layout::rustc::layout_of
21: 0x72c7aa5b6393 - <rustc_transmute[a389da957d26f46d]::layout::tree::Tree<rustc_transmute[a389da957d26f46d]::layout::rustc::Def, rustc_transmute[a389da957d26f46d]::layout::rustc::Ref>>::from_ty
22: 0x72c7aa5bc097 - <rustc_transmute[a389da957d26f46d]::rustc::TransmuteTypeEnv>::is_transmutable
23: 0x72c7aafa74d6 - <rustc_trait_selection[83d42188d813cc61]::traits::select::SelectionContext>::confirm_candidate
24: 0x72c7aaf45901 - <rustc_trait_selection[83d42188d813cc61]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}
25: 0x72c7aaf47773 - <rustc_trait_selection[83d42188d813cc61]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively
26: 0x72c7aaf52487 - <rustc_trait_selection[83d42188d813cc61]::traits::select::SelectionContext>::evaluate_root_obligation
27: 0x72c7aaf502bf - rustc_traits[280141601caf260c]::evaluate_obligation::evaluate_obligation
28: 0x72c7aaf4fda9 - rustc_query_impl[77fbfc8efa1d0dfd]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[77fbfc8efa1d0dfd]::query_impl::evaluate_obligation::dynamic_query::{closure#2}::{closure#0}, rustc_middle[8c2abaea4e51ae95]::query::erase::Erased<[u8; 2usize]>>
29: 0x72c7aaf4efb3 - rustc_query_system[73d5636c4135c7e]::query::plumbing::try_execute_query::<rustc_query_impl[77fbfc8efa1d0dfd]::DynamicConfig<rustc_query_system[73d5636c4135c7e]::query::caches::DefaultCache<rustc_type_ir[81db0f49f321e35d]::canonical::CanonicalQueryInput<rustc_middle[8c2abaea4e51ae95]::ty::context::TyCtxt, rustc_middle[8c2abaea4e51ae95]::ty::ParamEnvAnd<rustc_middle[8c2abaea4e51ae95]::ty::predicate::Predicate>>, rustc_middle[8c2abaea4e51ae95]::query::erase::Erased<[u8; 2usize]>>, false, false, false>, rustc_query_impl[77fbfc8efa1d0dfd]::plumbing::QueryCtxt, false>
30: 0x72c7aaf4ec1e - rustc_query_impl[77fbfc8efa1d0dfd]::query_impl::evaluate_obligation::get_query_non_incr::__rust_end_short_backtrace
31: 0x72c7ac0a4d16 - <rustc_trait_selection[83d42188d813cc61]::traits::fulfill::FulfillProcessor>::process_trait_obligation
32: 0x72c7ab79bdaf - <rustc_trait_selection[83d42188d813cc61]::traits::fulfill::FulfillProcessor as rustc_data_structures[cfad269df1308ded]::obligation_forest::ObligationProcessor>::process_obligation
33: 0x72c7aae079e9 - <rustc_data_structures[cfad269df1308ded]::obligation_forest::ObligationForest<rustc_trait_selection[83d42188d813cc61]::traits::fulfill::PendingPredicateObligation>>::process_obligations::<rustc_trait_selection[83d42188d813cc61]::traits::fulfill::FulfillProcessor>
34: 0x72c7ab5c078e - rustc_trait_selection[83d42188d813cc61]::traits::impossible_predicates
35: 0x72c7ab5bf785 - <rustc_mir_transform[31f24db7fba23339]::impossible_predicates::ImpossiblePredicates as rustc_mir_transform[31f24db7fba23339]::pass_manager::MirPass>::run_pass
36: 0x72c7aae0bc66 - rustc_mir_transform[31f24db7fba23339]::run_analysis_to_runtime_passes
37: 0x72c7ab0ab024 - rustc_mir_transform[31f24db7fba23339]::mir_drops_elaborated_and_const_checked
38: 0x72c7ab0aaa25 - rustc_query_impl[77fbfc8efa1d0dfd]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[77fbfc8efa1d0dfd]::query_impl::mir_drops_elaborated_and_const_checked::dynamic_query::{closure#2}::{closure#0}, rustc_middle[8c2abaea4e51ae95]::query::erase::Erased<[u8; 8usize]>>
39: 0x72c7ab0d452c - rustc_query_system[73d5636c4135c7e]::query::plumbing::try_execute_query::<rustc_query_impl[77fbfc8efa1d0dfd]::DynamicConfig<rustc_data_structures[cfad269df1308ded]::vec_cache::VecCache<rustc_span[45ddaf2096a5a8e9]::def_id::LocalDefId, rustc_middle[8c2abaea4e51ae95]::query::erase::Erased<[u8; 8usize]>, rustc_query_system[73d5636c4135c7e]::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl[77fbfc8efa1d0dfd]::plumbing::QueryCtxt, false>
40: 0x72c7ab0d3e0b - rustc_query_impl[77fbfc8efa1d0dfd]::query_impl::mir_drops_elaborated_and_const_checked::get_query_non_incr::__rust_end_short_backtrace
41: 0x72c7ab6f6a6b - rustc_interface[4b6516d07ac6860f]::passes::run_required_analyses
42: 0x72c7ab837c5e - rustc_interface[4b6516d07ac6860f]::passes::analysis
43: 0x72c7ab837c2d - rustc_query_impl[77fbfc8efa1d0dfd]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[77fbfc8efa1d0dfd]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[8c2abaea4e51ae95]::query::erase::Erased<[u8; 0usize]>>
44: 0x72c7abdcbcbd - rustc_query_system[73d5636c4135c7e]::query::plumbing::try_execute_query::<rustc_query_impl[77fbfc8efa1d0dfd]::DynamicConfig<rustc_query_system[73d5636c4135c7e]::query::caches::SingleCache<rustc_middle[8c2abaea4e51ae95]::query::erase::Erased<[u8; 0usize]>>, false, false, false>, rustc_query_impl[77fbfc8efa1d0dfd]::plumbing::QueryCtxt, false>
45: 0x72c7abdcb9b8 - rustc_query_impl[77fbfc8efa1d0dfd]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
46: 0x72c7ac00ee4d - rustc_interface[4b6516d07ac6860f]::passes::create_and_enter_global_ctxt::<core[e80f784d23167c2e]::option::Option<rustc_interface[4b6516d07ac6860f]::queries::Linker>, rustc_driver_impl[a82370bbe3079b02]::run_compiler::{closure#0}::{closure#2}>::{closure#2}::{closure#0}
47: 0x72c7abf2faaa - rustc_interface[4b6516d07ac6860f]::interface::run_compiler::<(), rustc_driver_impl[a82370bbe3079b02]::run_compiler::{closure#0}>::{closure#1}
48: 0x72c7abd87c48 - std[bdc4cefc0c032e43]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[4b6516d07ac6860f]::util::run_in_thread_with_globals<rustc_interface[4b6516d07ac6860f]::util::run_in_thread_pool_with_globals<rustc_interface[4b6516d07ac6860f]::interface::run_compiler<(), rustc_driver_impl[a82370bbe3079b02]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
49: 0x72c7abd88534 - <<std[bdc4cefc0c032e43]::thread::Builder>::spawn_unchecked_<rustc_interface[4b6516d07ac6860f]::util::run_in_thread_with_globals<rustc_interface[4b6516d07ac6860f]::util::run_in_thread_pool_with_globals<rustc_interface[4b6516d07ac6860f]::interface::run_compiler<(), rustc_driver_impl[a82370bbe3079b02]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core[e80f784d23167c2e]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
50: 0x72c7abd89937 - std::sys::pal::unix::thread::Thread::new::thread_start::h36ad1309f224e2da
51: 0x72c7a5ca370a - <unknown>
52: 0x72c7a5d27aac - <unknown>
53: 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 1.88.0-nightly (fedf10752 2025-03-30) running on x86_64-unknown-linux-gnu
query stack during panic:
#0 [layout_of] computing layout of `V`
#1 [evaluate_obligation] evaluating trait selection obligation `V: core::mem::transmutability::TransmuteFrom<(), core::mem::transmutability::Assume { alignment: false, lifetimes: false, safety: false, validity: false }>`
#2 [mir_drops_elaborated_and_const_checked] elaborating drops for `foo`
#3 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to 3 previous errors; 1 warning emitted
Some errors have detailed explanations: E0601, E0658.
For more information about an error, try `rustc --explain E0601`.
@rustbot label +F-non_lifetime_binders
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Reproduce the minimized example in a.rs with the reported nightly compiler. Read compiler/rustc_ty_utils/src/layout.rs around lines 627-639 and compiler/rustc_hir_analysis/src/collect/predicates_of.rs around line 396, following the stack trace through transmutability handling. Done means this input no longer triggers an internal compiler error and produces an appropriate diagnostic.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- rust
- Domain
- compilers
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 35/100