ICE: `Failed to normalize Alias(Weak, AliasTy {` with `feature(lazy_type_alias)`

[Naserume]

Code

#![feature(lazy_type_alias)]
#![allow(incomplete_features)]

struct Outer0<'a, T>(ExplicitTypeOutlives<'a, T>);
type ExplicitTypeOutlives<'a, T: 'a> = (&'a (), T);

pub struct Warns {
    _significant_drop: ExplicitTypeOutlives,
    field: String,
}

pub fn test(w: Warns) {
    _ = || drop(w.field);
}

fn main() {}

Meta

rustc --version --verbose:

rustc 1.81.0-nightly (cc8da78a0 2024-07-04)
binary: rustc
commit-hash: cc8da78a036dc3c15c35a97651b02af9a6d30c1e
commit-date: 2024-07-04
host: x86_64-apple-darwin
release: 1.81.0-nightly
LLVM version: 18.1.7

Error output

error[E0106]: missing lifetime specifier
 --> ./E9199.rs:8:24
  |
8 |     _significant_drop: ExplicitTypeOutlives,
  |                        ^^^^^^^^^^^^^^^^^^^^ expected named lifetime parameter
  |
help: consider introducing a named lifetime parameter
  |
7 ~ pub struct Warns<'a> {
8 ~     _significant_drop: ExplicitTypeOutlives<'a>,
  |

error[E0107]: missing generics for type alias `ExplicitTypeOutlives`
 --> ./E9199.rs:8:24
  |
8 |     _significant_drop: ExplicitTypeOutlives,
  |                        ^^^^^^^^^^^^^^^^^^^^ expected 1 generic argument
  |
note: type alias defined here, with 1 generic parameter: `T`
 --> ./E9199.rs:5:6
  |
5 | type ExplicitTypeOutlives<'a, T: 'a> = (&'a (), T);
  |      ^^^^^^^^^^^^^^^^^^^^     -
help: add missing generic argument
  |
8 |     _significant_drop: ExplicitTypeOutlives<T>,
  |                                            +++

Backtrace

error: internal compiler error: compiler/rustc_middle/src/ty/normalize_erasing_regions.rs:168:90: Failed to normalize Alias(Weak, AliasTy { args: ['{erased}, {type error}], def_id: DefId(0:8 ~ E9199[ca39]::ExplicitTypeOutlives) }), maybe try to call `try_normalize_erasing_regions` instead

thread 'rustc' panicked at compiler/rustc_middle/src/ty/normalize_erasing_regions.rs:168:90:
Box<dyn Any>
stack backtrace:
   0:        0x1094f2d93 - <std::sys::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hfeb614152c5fc770
   1:        0x10953e17b - core::fmt::write::h19d9b55d1716a641
   2:        0x1094e8b7e - std::io::Write::write_fmt::h65bfd6c063c93506
   3:        0x1094f2b81 - std::sys::backtrace::print::h6f13abc1d63a7b7a
   4:        0x1094f5959 - std::panicking::default_hook::{{closure}}::h53504a5e8286ae49
   5:        0x1094f56da - std::panicking::default_hook::h46ce4737ada06aa6
   6:        0x1127eb07c - std[96ba86566161595a]::panicking::update_hook::<alloc[d7368e4144f22d76]::boxed::Box<rustc_driver_impl[d6cc6074f4ffa8bf]::install_ice_hook::{closure#0}>>::{closure#0}
   7:        0x1094f6699 - std::panicking::rust_panic_with_hook::h3ebbbfeff58c5313
   8:        0x11285f177 - std[96ba86566161595a]::panicking::begin_panic::<rustc_errors[8113839328e8a1a6]::ExplicitBug>::{closure#0}
   9:        0x11284afb9 - std[96ba86566161595a]::sys::backtrace::__rust_end_short_backtrace::<std[96ba86566161595a]::panicking::begin_panic<rustc_errors[8113839328e8a1a6]::ExplicitBug>::{closure#0}, !>
  10:        0x117284fc9 - std[96ba86566161595a]::panicking::begin_panic::<rustc_errors[8113839328e8a1a6]::ExplicitBug>
  11:        0x1128712b6 - <rustc_errors[8113839328e8a1a6]::diagnostic::BugAbort as rustc_errors[8113839328e8a1a6]::diagnostic::EmissionGuarantee>::emit_producing_guarantee
  12:        0x113516315 - rustc_middle[3507220e01ce78dc]::util::bug::opt_span_bug_fmt::<rustc_span[9a6059d5c98a4f34]::span_encoding::Span>::{closure#0}
  13:        0x1134cbf57 - rustc_middle[3507220e01ce78dc]::ty::context::tls::with_opt::<rustc_middle[3507220e01ce78dc]::util::bug::opt_span_bug_fmt<rustc_span[9a6059d5c98a4f34]::span_encoding::Span>::{closure#0}, !>::{closure#0}
  14:        0x1134cba95 - rustc_middle[3507220e01ce78dc]::ty::context::tls::with_context_opt::<rustc_middle[3507220e01ce78dc]::ty::context::tls::with_opt<rustc_middle[3507220e01ce78dc]::util::bug::opt_span_bug_fmt<rustc_span[9a6059d5c98a4f34]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
  15:        0x11734862b - rustc_middle[3507220e01ce78dc]::util::bug::bug_fmt
  16:        0x11379fd3b - <rustc_mir_dataflow[ed1ee99526287f86]::elaborate_drops::DropCtxt<rustc_mir_transform[7f80daa91ef18b2a]::elaborate_drops::Elaborator>>::move_paths_for_fields
  17:        0x11379fe7a - <rustc_mir_dataflow[ed1ee99526287f86]::elaborate_drops::DropCtxt<rustc_mir_transform[7f80daa91ef18b2a]::elaborate_drops::Elaborator>>::open_drop_for_adt_contents
  18:        0x11379e2cb - <rustc_mir_dataflow[ed1ee99526287f86]::elaborate_drops::DropCtxt<rustc_mir_transform[7f80daa91ef18b2a]::elaborate_drops::Elaborator>>::elaborate_drop
  19:        0x1137ef038 - <alloc[d7368e4144f22d76]::vec::Vec<rustc_middle[3507220e01ce78dc]::mir::BasicBlock> as alloc[d7368e4144f22d76]::vec::spec_from_iter_nested::SpecFromIterNested<rustc_middle[3507220e01ce78dc]::mir::BasicBlock, core[677ae2db44f68e98]::iter::adapters::chain::Chain<core[677ae2db44f68e98]::iter::sources::once::Once<rustc_middle[3507220e01ce78dc]::mir::BasicBlock>, core[677ae2db44f68e98]::iter::adapters::map::Map<core[677ae2db44f68e98]::iter::adapters::zip::Zip<core[677ae2db44f68e98]::iter::adapters::rev::Rev<core[677ae2db44f68e98]::slice::iter::Iter<(rustc_middle[3507220e01ce78dc]::mir::syntax::Place, core[677ae2db44f68e98]::option::Option<rustc_mir_dataflow[ed1ee99526287f86]::move_paths::MovePathIndex>)>>, core[677ae2db44f68e98]::slice::iter::Iter<rustc_mir_dataflow[ed1ee99526287f86]::elaborate_drops::Unwind>>, <rustc_mir_dataflow[ed1ee99526287f86]::elaborate_drops::DropCtxt<rustc_mir_transform[7f80daa91ef18b2a]::elaborate_drops::Elaborator>>::drop_halfladder::{closure#0}>>>>::from_iter
  20:        0x11379d340 - <rustc_mir_dataflow[ed1ee99526287f86]::elaborate_drops::DropCtxt<rustc_mir_transform[7f80daa91ef18b2a]::elaborate_drops::Elaborator>>::drop_ladder
  21:        0x11379f180 - <rustc_mir_dataflow[ed1ee99526287f86]::elaborate_drops::DropCtxt<rustc_mir_transform[7f80daa91ef18b2a]::elaborate_drops::Elaborator>>::open_drop_for_tuple
  22:        0x11379e239 - <rustc_mir_dataflow[ed1ee99526287f86]::elaborate_drops::DropCtxt<rustc_mir_transform[7f80daa91ef18b2a]::elaborate_drops::Elaborator>>::elaborate_drop
  23:        0x1138b86c0 - <rustc_mir_transform[7f80daa91ef18b2a]::elaborate_drops::ElaborateDrops as rustc_middle[3507220e01ce78dc]::mir::MirPass>::run_pass
  24:        0x1137fd2ba - rustc_mir_transform[7f80daa91ef18b2a]::pass_manager::run_passes_inner
  25:        0x1138ae364 - rustc_mir_transform[7f80daa91ef18b2a]::run_analysis_to_runtime_passes
  26:        0x1138adeb7 - rustc_mir_transform[7f80daa91ef18b2a]::mir_drops_elaborated_and_const_checked
  27:        0x113eab7ac - rustc_query_impl[e04fdc29b284e1d7]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[e04fdc29b284e1d7]::query_impl::mir_drops_elaborated_and_const_checked::dynamic_query::{closure#2}::{closure#0}, rustc_middle[3507220e01ce78dc]::query::erase::Erased<[u8; 8usize]>>
  28:        0x113d2265e - rustc_query_system[31cd079b68d87400]::query::plumbing::try_execute_query::<rustc_query_impl[e04fdc29b284e1d7]::DynamicConfig<rustc_query_system[31cd079b68d87400]::query::caches::VecCache<rustc_hir[2175b85699631de1]::hir_id::OwnerId, rustc_middle[3507220e01ce78dc]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[e04fdc29b284e1d7]::plumbing::QueryCtxt, false>
  29:        0x113ebca2b - rustc_query_impl[e04fdc29b284e1d7]::query_impl::mir_drops_elaborated_and_const_checked::get_query_non_incr::__rust_end_short_backtrace
  30:        0x113162a98 - rustc_interface[dea1eaaf15b0b7c8]::passes::run_required_analyses
  31:        0x1131647f0 - rustc_interface[dea1eaaf15b0b7c8]::passes::analysis
  32:        0x113eabeac - rustc_query_impl[e04fdc29b284e1d7]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[e04fdc29b284e1d7]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[3507220e01ce78dc]::query::erase::Erased<[u8; 1usize]>>
  33:        0x113c8ac1e - rustc_query_system[31cd079b68d87400]::query::plumbing::try_execute_query::<rustc_query_impl[e04fdc29b284e1d7]::DynamicConfig<rustc_query_system[31cd079b68d87400]::query::caches::SingleCache<rustc_middle[3507220e01ce78dc]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[e04fdc29b284e1d7]::plumbing::QueryCtxt, false>
  34:        0x113eb6407 - rustc_query_impl[e04fdc29b284e1d7]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  35:        0x112794bb7 - <rustc_interface[dea1eaaf15b0b7c8]::queries::QueryResult<&rustc_middle[3507220e01ce78dc]::ty::context::GlobalCtxt>>::enter::<core[677ae2db44f68e98]::result::Result<(), rustc_span[9a6059d5c98a4f34]::ErrorGuaranteed>, rustc_driver_impl[d6cc6074f4ffa8bf]::run_compiler::{closure#0}::{closure#1}::{closure#5}>
  36:        0x1127f23cb - rustc_interface[dea1eaaf15b0b7c8]::interface::run_compiler::<core[677ae2db44f68e98]::result::Result<(), rustc_span[9a6059d5c98a4f34]::ErrorGuaranteed>, rustc_driver_impl[d6cc6074f4ffa8bf]::run_compiler::{closure#0}>::{closure#1}
  37:        0x1127dc9f1 - std[96ba86566161595a]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[dea1eaaf15b0b7c8]::util::run_in_thread_with_globals<rustc_interface[dea1eaaf15b0b7c8]::util::run_in_thread_pool_with_globals<rustc_interface[dea1eaaf15b0b7c8]::interface::run_compiler<core[677ae2db44f68e98]::result::Result<(), rustc_span[9a6059d5c98a4f34]::ErrorGuaranteed>, rustc_driver_impl[d6cc6074f4ffa8bf]::run_compiler::{closure#0}>::{closure#1}, core[677ae2db44f68e98]::result::Result<(), rustc_span[9a6059d5c98a4f34]::ErrorGuaranteed>>::{closure#0}, core[677ae2db44f68e98]::result::Result<(), rustc_span[9a6059d5c98a4f34]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[677ae2db44f68e98]::result::Result<(), rustc_span[9a6059d5c98a4f34]::ErrorGuaranteed>>
  38:        0x1127f8d96 - <<std[96ba86566161595a]::thread::Builder>::spawn_unchecked_<rustc_interface[dea1eaaf15b0b7c8]::util::run_in_thread_with_globals<rustc_interface[dea1eaaf15b0b7c8]::util::run_in_thread_pool_with_globals<rustc_interface[dea1eaaf15b0b7c8]::interface::run_compiler<core[677ae2db44f68e98]::result::Result<(), rustc_span[9a6059d5c98a4f34]::ErrorGuaranteed>, rustc_driver_impl[d6cc6074f4ffa8bf]::run_compiler::{closure#0}>::{closure#1}, core[677ae2db44f68e98]::result::Result<(), rustc_span[9a6059d5c98a4f34]::ErrorGuaranteed>>::{closure#0}, core[677ae2db44f68e98]::result::Result<(), rustc_span[9a6059d5c98a4f34]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[677ae2db44f68e98]::result::Result<(), rustc_span[9a6059d5c98a4f34]::ErrorGuaranteed>>::{closure#2} as core[677ae2db44f68e98]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  39:        0x1094ff83b - std::sys::pal::unix::thread::Thread::new::thread_start::he8797374daece752
  40:     0x7ff801f5318b - __pthread_start

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 `/Users/240703-nightly/rustc-ice-2024-07-05T01_57_08-90724.txt` to your bug report

query stack during panic:
#0 [mir_drops_elaborated_and_const_checked] elaborating drops for `test::{closure#0}`
#1 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to 3 previous errors

Some errors have detailed explanations: E0106, E0107.
For more information about an error, try `rustc --explain E0106`.

Note

Ice location:

rust/compiler/rustc_middle/src/ty/normalize_erasing_regions.rs

Lines 161 to 173 in cc8da78

	impl<'tcx> NormalizeAfterErasingRegionsFolder<'tcx> {
	fn normalize_generic_arg_after_erasing_regions(
	&self,
	arg: ty::GenericArg<'tcx>,
	) -> ty::GenericArg<'tcx> {
	let arg = self.param_env.and(arg);
	self.tcx.try_normalize_generic_arg_after_erasing_regions(arg).unwrap_or_else(|_| bug!(
	"Failed to normalize {:?}, maybe try to call `try_normalize_erasing_regions` instead",
	arg.value
	))
	}
	}

@rustbot label +F-lazy_type_alias +requires-incomplete-features

[GrigorenkoPV]

Bisects to #125667