type parameter T/#0 (T/0) out of range when substituting

[edg-l]

Code

trait Hello {
}

type HelloType<T = impl Hello> = T;

fn muchwow() -> HelloType {
    unimplemented!()
}


fn main() {
}

Playground Link

Meta

rustc --version --verbose:

rustc 1.52.0 (88f19c6da 2021-05-03)
binary: rustc
commit-hash: 88f19c6dab716c6281af7602e30f413e809c5974
commit-date: 2021-05-03
host: x86_64-unknown-linux-gnu
release: 1.52.0
LLVM version: 12.0.0

Error output

error: internal compiler error: compiler/rustc_middle/src/ty/subst.rs:529:17: type parameter `T/#0` (T/0) out of range when substituting, substs=[]
 --> src/main.rs:6:17
  |
6 | fn muchwow() -> HelloType {
  |                 ^^^^^^^^^

thread 'rustc' panicked at 'Box<Any>', /rustc/88f19c6dab716c6281af7602e30f413e809c5974/library/std/src/panic.rs:59:5
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 1.52.0 (88f19c6da 2021-05-03) running on x86_64-unknown-linux-gnu

note: compiler flags: -C embed-bitcode=no -C debuginfo=2 -C incremental --crate-type bin

note: some of the compiler flags provided by cargo are hidden

query stack during panic:
#0 [fn_sig] computing function signature of `muchwow`
#1 [collect_mod_item_types] collecting item types in top-level module
end of query stack
error: aborting due to previous error

error: could not compile `minimal`

To learn more, run the command again with --verbose.

Backtrace

thread 'rustc' panicked at 'Box<Any>', /rustc/88f19c6dab716c6281af7602e30f413e809c5974/library/std/src/panic.rs:59:5
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::structural_impls::<impl rustc_middle::ty::fold::TypeFoldable for &rustc_middle::ty::TyS>::super_fold_with
  10: <<dyn rustc_typeck::astconv::AstConv>::create_substs_for_ast_path::SubstsForAstPathCtxt as rustc_typeck::astconv::CreateSubstsForGenericArgsCtxt>::inferred_kind
  11: <dyn rustc_typeck::astconv::AstConv>::create_substs_for_ast_path
  12: <dyn rustc_typeck::astconv::AstConv>::ast_path_substs_for_ty
  13: <dyn rustc_typeck::astconv::AstConv>::ast_path_to_ty
  14: <dyn rustc_typeck::astconv::AstConv>::ast_ty_to_ty_inner
  15: <dyn rustc_typeck::astconv::AstConv>::ty_of_fn
  16: rustc_typeck::collect::fn_sig
  17: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  18: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  19: rustc_data_structures::stack::ensure_sufficient_stack
  20: rustc_query_system::query::plumbing::force_query_with_job
  21: rustc_query_system::query::plumbing::get_query_impl
  22: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::fn_sig
  23: rustc_typeck::collect::convert_item
  24: <rustc_typeck::collect::CollectItemTypesVisitor as rustc_hir::intravisit::Visitor>::visit_item
  25: rustc_middle::hir::map::Map::visit_item_likes_in_module
  26: rustc_typeck::collect::collect_mod_item_types
  27: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  28: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  29: rustc_query_system::query::plumbing::force_query_with_job
  30: rustc_query_system::query::plumbing::get_query_impl
  31: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::collect_mod_item_types
  32: rustc_session::session::Session::track_errors
  33: rustc_typeck::check_crate
  34: rustc_interface::passes::analysis
  35: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  36: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  37: rustc_data_structures::stack::ensure_sufficient_stack
  38: rustc_query_system::query::plumbing::force_query_with_job
  39: rustc_query_system::query::plumbing::get_query_impl
  40: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::analysis
  41: rustc_interface::passes::QueryContext::enter
  42: rustc_interface::queries::<impl rustc_interface::interface::Compiler>::enter
  43: rustc_span::with_source_map
  44: rustc_interface::interface::create_compiler_and_run
  45: scoped_tls::ScopedKey<T>::set
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

[SNCPlay42]

Duplicate of #82952, which is already fixed on nightly/beta.