[ICE]: builtin: `no entry found for key`

[matthiaskrgr]

snippet:

#![feature(non_lifetime_binders)]
#![feature(derive_coerce_pointee)]

#[derive(core::marker::CoercePointee)]
#[repr(transparent)]
struct _Ptr5<'a, #[pointee] T: ?Sized, X>
where
    for<V> V: Sized,
{
    data: &'a T,
    x: core::marker::PhantomData<X>,
}

fn main() {}

Version information

rustc 1.95.0-nightly (1500f0f47 2026-02-22)
binary: rustc
commit-hash: 1500f0f47f5fe8ddcd6528f6c6c031b210b4eac5
commit-date: 2026-02-22
host: x86_64-unknown-linux-gnu
release: 1.95.0-nightly
LLVM version: 22.1.0

Possibly related line of code:

rust/compiler/rustc_lint/src/builtin.rs

Lines 2123 to 2135 in 1500f0f

	// and should check for them here.
	match predicate.bounded_ty.kind {
	hir::TyKind::Path(hir::QPath::Resolved(None, path)) => {
	let Res::Def(DefKind::TyParam, def_id) = path.res else {
	continue;
	};
	let index = ty_generics.param_def_id_to_index[&def_id];
	(
	Self::lifetimes_outliving_type(
	// don't warn if the inferred span actually came from the predicate we're looking at
	// this happens if the type is recursively defined
	inferred_outlives.iter().filter(|(_, span)| {
	!where_predicate.span.contains(*span)

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.KTL1jjCwUirK/rustc_testrunner_tmpdir_reporting.0pS52XrH28EG/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


thread 'rustc' (435403) panicked at /rustc-dev/1500f0f47f5fe8ddcd6528f6c6c031b210b4eac5/compiler/rustc_lint/src/builtin.rs:2129:82:
no entry found for key
stack backtrace:
   0:     0x7f71b2fb80eb - <<std[8fa6c4d7877d9fa6]::sys::backtrace::BacktraceLock>::print::DisplayBacktrace as core[8d2c922a005dfed9]::fmt::Display>::fmt
   1:     0x7f71b3621648 - core[8d2c922a005dfed9]::fmt::write
   2:     0x7f71b2fcf0f6 - <std[8fa6c4d7877d9fa6]::sys::stdio::unix::Stderr as std[8fa6c4d7877d9fa6]::io::Write>::write_fmt
   3:     0x7f71b2f8e1d8 - std[8fa6c4d7877d9fa6]::panicking::default_hook::{closure#0}
   4:     0x7f71b2fab553 - std[8fa6c4d7877d9fa6]::panicking::default_hook
   5:     0x7f71b1f84080 - std[8fa6c4d7877d9fa6]::panicking::update_hook::<alloc[e536beed0316d181]::boxed::Box<rustc_driver_impl[f1389595c05d78d8]::install_ice_hook::{closure#1}>>::{closure#0}
   6:     0x7f71b2fab832 - std[8fa6c4d7877d9fa6]::panicking::panic_with_hook
   7:     0x7f71b2f8e298 - std[8fa6c4d7877d9fa6]::panicking::panic_handler::{closure#0}
   8:     0x7f71b2f84fe9 - std[8fa6c4d7877d9fa6]::sys::backtrace::__rust_end_short_backtrace::<std[8fa6c4d7877d9fa6]::panicking::panic_handler::{closure#0}, !>
   9:     0x7f71b2f8fcfd - __rustc[d7af78fd024a5d6e]::rust_begin_unwind
  10:     0x7f71b03ed78c - core[8d2c922a005dfed9]::panicking::panic_fmt
  11:     0x7f71b0908d54 - core[8d2c922a005dfed9]::option::expect_failed
  12:     0x7f71b3e9970c - <rustc_lint[9cd29c06b98b2fa7]::builtin::ExplicitOutlivesRequirements as rustc_lint[9cd29c06b98b2fa7]::passes::LateLintPass>::check_item
  13:     0x7f71b3e962e4 - <rustc_lint[9cd29c06b98b2fa7]::BuiltinCombinedModuleLateLintPass as rustc_lint[9cd29c06b98b2fa7]::passes::LateLintPass>::check_item
  14:     0x7f71b3e880b4 - <rustc_lint[9cd29c06b98b2fa7]::late::LateContextAndPass<rustc_lint[9cd29c06b98b2fa7]::BuiltinCombinedModuleLateLintPass> as rustc_hir[d032c852da3aa8c5]::intravisit::Visitor>::visit_nested_item
  15:     0x7f71b3e869ed - rustc_lint[9cd29c06b98b2fa7]::lint_mod
  16:     0x7f71b45c7304 - rustc_query_impl[cec139e1f3385ac4]::execution::try_execute_query::<rustc_middle[60c2cf3af82b0a08]::query::caches::DefaultCache<rustc_span[8a11d63785993c5a]::def_id::LocalModDefId, rustc_middle[60c2cf3af82b0a08]::query::erase::ErasedData<[u8; 0usize]>>, {rustc_query_impl[cec139e1f3385ac4]::QueryFlags { is_anon: false, is_depth_limit: false, is_feedable: false }}, false>
  17:     0x7f71b45c7099 - rustc_query_impl[cec139e1f3385ac4]::query_impl::lint_mod::get_query_non_incr::__rust_end_short_backtrace
  18:     0x7f71b45c8350 - rustc_lint[9cd29c06b98b2fa7]::late::check_crate::{closure#1}
  19:     0x7f71b45c7f3a - rustc_lint[9cd29c06b98b2fa7]::late::check_crate
  20:     0x7f71b45c53c4 - rustc_interface[b6ce98af9df5606d]::passes::analysis::{closure#0}::{closure#0}::{closure#2}
  21:     0x7f71b45c51a5 - rustc_data_structures[1a0237db0a3cda6a]::sync::parallel::par_fns
  22:     0x7f71b45c5142 - rustc_interface[b6ce98af9df5606d]::passes::analysis::{closure#0}::{closure#0}
  23:     0x7f71b45c51a5 - rustc_data_structures[1a0237db0a3cda6a]::sync::parallel::par_fns
  24:     0x7f71b3db53b8 - rustc_interface[b6ce98af9df5606d]::passes::analysis
  25:     0x7f71b47e1499 - rustc_query_impl[cec139e1f3385ac4]::execution::try_execute_query::<rustc_middle[60c2cf3af82b0a08]::query::caches::SingleCache<rustc_middle[60c2cf3af82b0a08]::query::erase::ErasedData<[u8; 0usize]>>, {rustc_query_impl[cec139e1f3385ac4]::QueryFlags { is_anon: false, is_depth_limit: false, is_feedable: false }}, false>
  26:     0x7f71b47e10c8 - rustc_query_impl[cec139e1f3385ac4]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  27:     0x7f71b482088b - rustc_interface[b6ce98af9df5606d]::interface::run_compiler::<(), rustc_driver_impl[f1389595c05d78d8]::run_compiler::{closure#0}>::{closure#1}
  28:     0x7f71b47d09fe - std[8fa6c4d7877d9fa6]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[b6ce98af9df5606d]::util::run_in_thread_with_globals<rustc_interface[b6ce98af9df5606d]::util::run_in_thread_pool_with_globals<rustc_interface[b6ce98af9df5606d]::interface::run_compiler<(), rustc_driver_impl[f1389595c05d78d8]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
  29:     0x7f71b47d10e0 - <std[8fa6c4d7877d9fa6]::thread::lifecycle::spawn_unchecked<rustc_interface[b6ce98af9df5606d]::util::run_in_thread_with_globals<rustc_interface[b6ce98af9df5606d]::util::run_in_thread_pool_with_globals<rustc_interface[b6ce98af9df5606d]::interface::run_compiler<(), rustc_driver_impl[f1389595c05d78d8]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core[8d2c922a005dfed9]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  30:     0x7f71b47d1f6c - <std[8fa6c4d7877d9fa6]::sys::thread::unix::Thread>::new::thread_start
  31:     0x7f71ae2a598b - <unknown>
  32:     0x7f71ae329a0c - <unknown>
  33:                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: rustc 1.95.0-nightly (1500f0f47 2026-02-22) running on x86_64-unknown-linux-gnu

query stack during panic:
#0 [lint_mod] linting top-level module
#1 [analysis] running analysis passes on crate `mvce`
end of query stack
warning: 1 warning emitted

@rustbot label +F-non_lifetime_binders +F-derive_coerce_pointee