ICE when running cargo fix --edition: error computing signigicant drop

[afetisov]

Code

use std::rc::Rc;

struct S<N, T>(Rc<(N, T)>);

impl<N, T> S<N, T> {
    fn new() -> Self {
        loop {}
    }
}

pub fn test() {
    let code = S::<(), ()>::new();
    let _ = || code;
}

Error output

$> cargo fix --edition --allow-dirty --allow-staged -j1
    Checking ice v0.1.0 (/home/user/untitled)
   Migrating src/lib.rs from 2018 edition to 2021
error: internal compiler error: compiler/rustc_middle/src/ty/subst.rs:534:17: type parameter `T/#1` (T/1) out of range when substituting, substs=[(N, T)]

thread 'rustc' panicked at 'Box<dyn Any>', /rustc/09c42c45858d5f3aedfa670698275303a3d19afa/compiler/rustc_errors/src/lib.rs:1093:9
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 1.56.0 (09c42c458 2021-10-18) running on x86_64-unknown-linux-gnu

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

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

query stack during panic:
#0 [adt_significant_drop_tys] computing when `S` has a significant destructor
#1 [has_significant_drop_raw] computing whether `S<(), ()>` has a significant drop
end of query stack
error: could not compile `ice`

Backtrace

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: <rustc_ty_utils::needs_drop::NeedsDropTypes<F> as core::iter::traits::iterator::Iterator>::next
  11: <core::iter::adapters::ResultShunt<I,E> as core::iter::traits::iterator::Iterator>::next
  12: <alloc::vec::Vec<T> as alloc::vec::spec_from_iter::SpecFromIter<T,I>>::from_iter
  13: core::iter::adapters::process_results
  14: rustc_ty_utils::needs_drop::adt_significant_drop_tys
  15: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  16: rustc_data_structures::stack::ensure_sufficient_stack
  17: rustc_query_system::query::plumbing::force_query_with_job
  18: rustc_query_system::query::plumbing::get_query_impl
  19: rustc_query_system::query::plumbing::get_query
  20: rustc_ty_utils::needs_drop::has_significant_drop_raw
  21: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  22: rustc_data_structures::stack::ensure_sufficient_stack
  23: rustc_query_system::query::plumbing::get_query_impl
  24: rustc_query_system::query::plumbing::get_query
  25: rustc_middle::ty::util::<impl rustc_middle::ty::TyS>::has_significant_drop
  26: rustc_typeck::check::upvar::<impl rustc_typeck::check::fn_ctxt::FnCtxt>::analyze_closure
  27: <rustc_typeck::check::upvar::InferBorrowKindVisitor as rustc_hir::intravisit::Visitor>::visit_expr
  28: rustc_hir::intravisit::walk_stmt
  29: rustc_hir::intravisit::walk_expr
  30: <rustc_typeck::check::upvar::InferBorrowKindVisitor as rustc_hir::intravisit::Visitor>::visit_expr
  31: rustc_typeck::check::upvar::<impl rustc_typeck::check::fn_ctxt::FnCtxt>::closure_analyze
  32: rustc_infer::infer::InferCtxtBuilder::enter
  33: rustc_typeck::check::typeck
  34: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  35: rustc_data_structures::stack::ensure_sufficient_stack
  36: rustc_query_system::query::plumbing::force_query_with_job
  37: rustc_query_system::query::plumbing::force_query_impl
  38: rustc_query_impl::query_callbacks::typeck::force_from_dep_node
  39: rustc_query_system::dep_graph::graph::DepGraph<K>::try_mark_previous_green
  40: rustc_query_system::query::plumbing::ensure_must_run
  41: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::typeck
  42: rustc_middle::ty::<impl rustc_middle::ty::context::TyCtxt>::par_body_owners
  43: rustc_typeck::check::typeck_item_bodies
  44: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  45: rustc_query_system::query::plumbing::force_query_with_job
  46: rustc_query_system::query::plumbing::get_query_impl
  47: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::typeck_item_bodies
  48: rustc_session::utils::<impl rustc_session::session::Session>::time
  49: rustc_typeck::check_crate
  50: rustc_interface::passes::analysis
  51: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  52: rustc_data_structures::stack::ensure_sufficient_stack
  53: rustc_query_system::query::plumbing::force_query_with_job
  54: rustc_query_system::query::plumbing::get_query_impl
  55: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::analysis
  56: rustc_interface::passes::QueryContext::enter
  57: rustc_interface::queries::<impl rustc_interface::interface::Compiler>::enter
  58: rustc_span::with_source_map
  59: scoped_tls::ScopedKey<T>::set
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

[ehuss]

Thanks for the report, and the very nice and concise reproduction. I'm pretty certain that this is the same as #90024, so closing to keep the discussion in one place.