ICE: compiler/rustc_middle/src/ty/subst.rs:538:17: type parameter T/#0 (T/0) out of range when substituting, substs=[]

[Cancelll]

Code

#![feature(const_generics)]
struct Foo<T = [u8; std]> {}
impl Foo {}

Meta

rustc --version --verbose:

rustc 1.54.0-nightly (0a8629bff 2021-06-11)
binary: rustc
commit-hash: 0a8629bff642c3c3b84bb644c0099194f063b627
commit-date: 2021-06-11
host: x86_64-unknown-linux-gnu
release: 1.54.0-nightly
LLVM version: 12.0.1

Error output

error[E0423]: expected value, found crate `std`
 --> mutant.rs:2:21
  |
2 | struct Foo<T = [u8; std]> {}
  |                     ^^^ not a value

warning: the feature `const_generics` is incomplete and may not be safe to use and/or cause compiler crashes
 --> mutant.rs:1:12
  |
1 | #![feature(const_generics)]
  |            ^^^^^^^^^^^^^^
  |
  = note: `#[warn(incomplete_features)]` on by default
  = note: see issue #44580 <https://github.com/rust-lang/rust/issues/44580> for more information

error: internal compiler error: compiler/rustc_middle/src/ty/subst.rs:538:17: type parameter `T/#0` (T/0) out of range when substituting, substs=[]
 --> mutant.rs:3:6
  |
3 | impl Foo {}
  |      ^^^

thread 'rustc' panicked at 'Box<dyn Any>', /rustc/0a8629bff642c3c3b84bb644c0099194f063b627/compiler/rustc_errors/src/lib.rs:953:9
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

note: 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: rustc 1.54.0-nightly (0a8629bff 2021-06-11) running on x86_64-unknown-linux-gnu

note: compiler flags: -Z mir-opt-level=3 -Z new-llvm-pass-manager=yes -Z unsound-mir-opts=yes -Z polonius=yes -Z polymorphize=yes -C debuginfo=2 -C opt-level=3 --crate-type staticlib

query stack during panic:
#0 [type_of] computing type of `<impl at mutant.rs:3:1: 3:12>`
#1 [collect_mod_item_types] collecting item types in top-level module
end of query stack
error: aborting due to 2 previous errors; 1 warning emitted

For more information about this error, try `rustc --explain E0423`.

Backtrace

error[E0423]: expected value, found crate `std`
 --> mutant.rs:2:21
  |
2 | struct Foo<T = [u8; std]> {}
  |                     ^^^ not a value

warning: the feature `const_generics` is incomplete and may not be safe to use and/or cause compiler crashes
 --> mutant.rs:1:12
  |
1 | #![feature(const_generics)]
  |            ^^^^^^^^^^^^^^
  |
  = note: `#[warn(incomplete_features)]` on by default
  = note: see issue #44580 <https://github.com/rust-lang/rust/issues/44580> for more information

error: internal compiler error: compiler/rustc_middle/src/ty/subst.rs:538:17: type parameter `T/#0` (T/0) out of range when substituting, substs=[]
 --> mutant.rs:3:6
  |
3 | impl Foo {}
  |      ^^^

thread 'rustc' panicked at 'Box<dyn Any>', /rustc/0a8629bff642c3c3b84bb644c0099194f063b627/compiler/rustc_errors/src/lib.rs:953:9
stack backtrace:
   0: std::panicking::begin_panic
   1: std::panic::panic_any
   2: rustc_errors::HandlerInner::span_bug
   3: rustc_errors::Handler::span_bug
   4: rustc_middle::ty::context::tls::with_opt
   5: rustc_middle::util::bug::opt_span_bug_fmt
   6: rustc_middle::util::bug::span_bug_fmt
   7: <rustc_middle::ty::subst::SubstFolder as rustc_middle::ty::fold::TypeFolder>::fold_ty
   8: rustc_middle::ty::fold::TypeFoldable::fold_with
   9: <rustc_middle::ty::subst::SubstFolder as rustc_middle::ty::fold::TypeFolder>::fold_const
  10: rustc_middle::ty::structural_impls::<impl rustc_middle::ty::fold::TypeFoldable for &rustc_middle::ty::TyS>::super_fold_with
  11: <<dyn rustc_typeck::astconv::AstConv>::create_substs_for_ast_path::SubstsForAstPathCtxt as rustc_typeck::astconv::CreateSubstsForGenericArgsCtxt>::inferred_kind
  12: <dyn rustc_typeck::astconv::AstConv>::create_substs_for_ast_path
  13: <dyn rustc_typeck::astconv::AstConv>::ast_path_substs_for_ty
  14: <dyn rustc_typeck::astconv::AstConv>::ast_path_to_ty
  15: <dyn rustc_typeck::astconv::AstConv>::ast_ty_to_ty_inner
  16: rustc_typeck::collect::type_of::type_of
  17: rustc_query_system::query::plumbing::get_query_impl
  18: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::type_of
  19: rustc_typeck::collect::convert_item
  20: <rustc_typeck::collect::CollectItemTypesVisitor as rustc_hir::intravisit::Visitor>::visit_item
  21: rustc_middle::hir::map::Map::visit_item_likes_in_module
  22: rustc_typeck::collect::collect_mod_item_types
  23: rustc_query_system::query::plumbing::get_query_impl
  24: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::collect_mod_item_types
  25: rustc_session::session::Session::track_errors
  26: rustc_typeck::check_crate
  27: rustc_interface::passes::analysis
  28: rustc_query_system::query::plumbing::get_query_impl
  29: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::analysis
  30: rustc_interface::queries::<impl rustc_interface::interface::Compiler>::enter
  31: rustc_span::with_source_map
  32: rustc_interface::interface::create_compiler_and_run
  33: scoped_tls::ScopedKey<T>::set
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

note: 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: rustc 1.54.0-nightly (0a8629bff 2021-06-11) running on x86_64-unknown-linux-gnu

note: compiler flags: -Z mir-opt-level=3 -Z new-llvm-pass-manager=yes -Z unsound-mir-opts=yes -Z polonius=yes -Z polymorphize=yes -C debuginfo=2 -C opt-level=3 --crate-type staticlib

query stack during panic:
#0 [type_of] computing type of `<impl at mutant.rs:3:1: 3:12>`
#1 [collect_mod_item_types] collecting item types in top-level module
#2 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to 2 previous errors; 1 warning emitted

For more information about this error, try `rustc --explain E0423`.

[Cancelll]

Possibly related to #83938

[BoxyUwU]

I think this is the same ICE as that issue yeah

[oli-obk]

closing as duplicate of #83938