[ICE in subst.rs] with missing min_const_generics feature

[leonardo-m]

const fn foo(n: usize) -> usize { n }
fn bar<const N: usize>() -> [u32; foo(N)] {
    [0; foo(N)]
}
fn main() {}

Generates the error message:

error[E0658]: const generics are unstable
 --> ...\test.rs:2:14
  |
2 | fn bar<const N: usize>() -> [u32; foo(N)] {
  |              ^
  |
  = note: see issue #74878 <https://github.com/rust-lang/rust/issues/74878> for more information
  = help: add `#![feature(min_const_generics)]` to the crate attributes to enable

error: internal compiler error: compiler\rustc_middle\src\ty\subst.rs:568:17: const parameter `N/#0` (Const { ty: usize, val: Param(N/#0) }/0) out of range when substituting substs=[]

thread 'rustc' panicked at 'Box<Any>', /rustc/593fe977a77ad5a7aec23c6cb0f86a3470221670\compiler\rustc_errors\src\lib.rs:904:9
stack backtrace:
   0: std::panicking::begin_panic
   1: rustc_errors::HandlerInner::span_bug
   2: rustc_errors::Handler::span_bug
   3: rustc_middle::util::bug::opt_span_bug_fmt::{{closure}}
   4: rustc_middle::ty::context::tls::with_opt::{{closure}}
   5: rustc_middle::ty::context::tls::with_opt
   6: rustc_middle::util::bug::opt_span_bug_fmt
   7: rustc_middle::util::bug::span_bug_fmt
   8: <rustc_middle::ty::subst::SubstFolder as rustc_middle::ty::fold::TypeFolder>::fold_const
   9: rustc_middle::ty::normalize_erasing_regions::<impl rustc_middle::ty::context::TyCtxt>::subst_and_normalize_erasing_regions
  10: rustc_mir::interpret::operand::<impl rustc_mir::interpret::eval_context::InterpCx<M>>::eval_operand
  11: <core::iter::adapters::ResultShunt<I,E> as core::iter::traits::iterator::Iterator>::next
  12: <alloc::vec::Vec<T> as alloc::vec::SpecFromIter<T,I>>::from_iter
  13: rustc_mir::interpret::step::<impl rustc_mir::interpret::eval_context::InterpCx<M>>::run
  14: rustc_mir::const_eval::eval_queries::eval_to_allocation_raw_provider
  15: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::eval_to_allocation_raw>::compute
  16: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task
  17: rustc_data_structures::stack::ensure_sufficient_stack
  18: rustc_query_system::query::plumbing::get_query_impl
  19: rustc_mir::const_eval::eval_queries::eval_to_const_value_raw_provider
  20: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::eval_to_const_value_raw>::compute
  21: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task
  22: rustc_data_structures::stack::ensure_sufficient_stack
  23: rustc_query_system::query::plumbing::get_query_impl
  24: rustc_mir::const_eval::eval_queries::eval_to_const_value_raw_provider
  25: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::eval_to_const_value_raw>::compute
  26: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task
  27: rustc_data_structures::stack::ensure_sufficient_stack
  28: rustc_query_system::query::plumbing::get_query_impl
  29: rustc_middle::mir::interpret::queries::<impl rustc_middle::ty::context::TyCtxt>::const_eval_global_id
  30: rustc_middle::mir::interpret::queries::<impl rustc_middle::ty::context::TyCtxt>::const_eval_resolve
  31: rustc_middle::ty::consts::kind::ConstKind::try_eval
  32: <rustc_trait_selection::traits::project::AssocTypeNormalizer as rustc_middle::ty::fold::TypeFolder>::fold_const
  33: rustc_middle::ty::structural_impls::<impl rustc_middle::ty::fold::TypeFoldable for &rustc_middle::ty::TyS>::super_fold_with
  34: <rustc_trait_selection::traits::project::AssocTypeNormalizer as rustc_middle::ty::fold::TypeFolder>::fold_ty
  35: rustc_middle::ty::util::fold_list
  36: rustc_trait_selection::traits::project::AssocTypeNormalizer::fold
  37: rustc_data_structures::stack::ensure_sufficient_stack
  38: rustc_trait_selection::traits::project::normalize
  39: <rustc_infer::infer::InferCtxt as rustc_trait_selection::infer::InferCtxtExt>::partially_normalize_associated_types_in
  40: rustc_typeck::check::inherited::Inherited::normalize_associated_types_in
  41: rustc_infer::infer::InferCtxtBuilder::enter
  42: rustc_typeck::check::wfcheck::check_item_well_formed
  43: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::check_item_well_formed>::compute
  44: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task
  45: rustc_data_structures::stack::ensure_sufficient_stack
  46: rustc_query_system::query::plumbing::get_query_impl
  47: rustc_query_system::query::plumbing::ensure_query_impl
  48: rustc_data_structures::sync::par_for_each_in
  49: rustc_hir::hir::Crate::par_visit_all_item_likes
  50: rustc_session::session::Session::track_errors
  51: rustc_typeck::check_crate
  52: rustc_interface::passes::analysis
  53: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::analysis>::compute
  54: rustc_query_system::dep_graph::graph::DepGraph<K>::with_eval_always_task
  55: rustc_data_structures::stack::ensure_sufficient_stack
  56: rustc_query_system::query::plumbing::get_query_impl
  57: rustc_interface::passes::QueryContext::enter
  58: rustc_interface::queries::<impl rustc_interface::interface::Compiler>::enter
  59: rustc_span::with_source_map
  60: 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 1.50.0-nightly (593fe977a 2020-11-20) running on x86_64-pc-windows-gnu

query stack during panic:
#0 [eval_to_allocation_raw] const-evaluating + checking `bar::{constant#0}`
#1 [eval_to_const_value_raw] simplifying constant for the type system `bar::{constant#0}`
#2 [eval_to_const_value_raw] simplifying constant for the type system `bar::{constant#0}`
#3 [check_item_well_formed] checking that `bar` is well-formed
#4 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0658`.

Tool completed with exit code 101

[lcnr]

duplicate of #56445 and related issues