[ICE]: could not normalize `Foo: 'static`
Open
Nobody has claimed this yet.
C-bug
F-checked_type_aliases
I-ICE
T-compiler
WG-trait-system-refactor
- Dominant language
- Rust
- Stars
- 119k
- Forks
- 16.1k
- PR merge metrics
- PR metrics pending
Description
Code
//@ compile-flags -Znext-solver=globally
#![feature(lazy_type_alias)]
#![feature(trivial_bounds)]
type Foo
= ()
where
Foo: 'static;
fn main() {}
Meta
rustc --version --verbose:
rustc 1.97.0-nightly (507271bc1 2026-05-17)
binary: rustc
commit-hash: 507271bc119683008ec719ecee48814e8ac86c65
commit-date: 2026-05-17
host: x86_64-unknown-linux-gnu
release: 1.97.0-nightly
LLVM version: 22.1.4
Error output
<output>
Backtrace
warning: the feature `lazy_type_alias` is incomplete and may not be safe to use and/or cause compiler crashes
--> a.rs:2:12
|
2 | #![feature(lazy_type_alias)]
| ^^^^^^^^^^^^^^^
|
= note: see issue #112792 <https://github.com/rust-lang/rust/issues/112792> for more information
= note: `#[warn(incomplete_features)]` on by default
warning: type alias `Foo` is never used
--> a.rs:4:6
|
4 | type Foo
| ^^^
|
= note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
warning: lifetime bound Foo: 'static does not depend on any type or lifetime parameters
--> a.rs:7:10
|
7 | Foo: 'static;
| ^^^^^^^
|
= note: `#[warn(trivial_bounds)]` on by default
warning: 3 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: could not normalize `Foo: 'static`
|
= note: delayed at /rustc-dev/507271bc119683008ec719ecee48814e8ac86c65/compiler/rustc_trait_selection/src/regions.rs:42:41
0: <rustc_errors::DiagCtxtInner>::emit_diagnostic
1: <rustc_errors::DiagCtxtHandle>::emit_diagnostic
2: <rustc_span::ErrorGuaranteed as rustc_errors::diagnostic::EmissionGuarantee>::emit_producing_guarantee
3: <rustc_errors::DiagCtxtHandle>::delayed_bug::<alloc::string::String>
4: <rustc_infer::infer::outlives::env::OutlivesEnvironment as rustc_trait_selection::regions::OutlivesEnvironmentBuildExt>::new_with_implied_bounds_compat::<core::iter::adapters::copied::Copied<indexmap::set::iter::Iter<rustc_middle::ty::Ty>>>
5: rustc_hir_analysis::check::check::check_item_type
6: rustc_hir_analysis::check::wfcheck::check_well_formed
7: rustc_query_impl::query_impl::check_well_formed::invoke_provider_fn::__rust_begin_short_backtrace
8: rustc_query_impl::execution::try_execute_query::<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::ErasedData<[u8; 1]>, rustc_middle::dep_graph::graph::DepNodeIndex>, false>
9: rustc_query_impl::query_impl::check_well_formed::execute_query_non_incr::__rust_end_short_backtrace
10: rustc_hir_analysis::check::wfcheck::check_type_wf
11: rustc_query_impl::query_impl::check_type_wf::invoke_provider_fn::__rust_begin_short_backtrace
12: rustc_query_impl::execution::try_execute_query::<rustc_middle::query::caches::SingleCache<rustc_middle::query::erase::ErasedData<[u8; 1]>>, false>
13: rustc_query_impl::query_impl::check_type_wf::execute_query_non_incr::__rust_end_short_backtrace
14: rustc_hir_analysis::check_crate
15: rustc_interface::passes::analysis
16: rustc_query_impl::execution::try_execute_query::<rustc_middle::query::caches::SingleCache<rustc_middle::query::erase::ErasedData<[u8; 0]>>, false>
17: rustc_query_impl::query_impl::analysis::execute_query_non_incr::__rust_end_short_backtrace
18: rustc_interface::interface::run_compiler::<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}
19: 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#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
20: <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#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
21: <std::sys::thread::unix::Thread>::new::thread_start
22: <unknown>
23: <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: please attach the file at `/tmp/im4/2/rustc-ice-2026-05-18T09_14_18-2216916.txt` to your bug report
note: rustc 1.97.0-nightly (507271bc1 2026-05-17) running on x86_64-unknown-linux-gnu
note: compiler flags: -Z next-solver=globally
query stack during panic:
end of query stack
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 minimal example with -Znext-solver=globally on a current nightly, then inspect compiler/rustc_trait_selection/src/regions.rs around the delayed-bug location and the new_with_implied_bounds_compat call in the backtrace. Trace why normalization of Foo: 'static reaches the ICE, and verify the example no longer emits an internal compiler error.
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
- Active
- Clarity
- Mostly clear
- Newbie friendliness
- 45/100