ICE: `index out of bounds: the len is 12 but the index is 13`

[matthiaskrgr]

auto-reduced (treereduce-rust):

//@compile-flags: -Zunstable-options --edition=2024 --crate-type=lib
pub async fn async_closure(x: &mut i32) {
    let c = async move || {
        *x += 1;
    };
    call_once(c).await;
}

fn call_once<T>(f: impl FnOnce() -> T) -> T {
    f()
}

original:

//@ check-pass
//@ edition: 2021
// Precise capture struct by move, consume field

struct Vec { a: i32 }

pub async fn async_closure(x: &mut i32) {
    let c = async move || {
        *x += 1;
    };
    call_once(c).await;
}

fn call_once<T>(f: impl FnOnce() -> T) -> T {
    f()
}

Version information

rustc 1.85.0-nightly (4790a435c 2024-12-15)
binary: rustc
commit-hash: 4790a435cbcb55c94ccdef51bf7a9b2e55824528
commit-date: 2024-12-15
host: x86_64-unknown-linux-gnu
release: 1.85.0-nightly
LLVM version: 19.1.5

Command:
/home/matthias/.rustup/toolchains/master/bin/rustc -Zunstable-options --edition=2024 --crate-type=lib

Program output

thread 'rustc' panicked at /rustc/4790a435cbcb55c94ccdef51bf7a9b2e55824528/compiler/rustc_middle/src/hir/mod.rs:179:84:
index out of bounds: the len is 12 but the index is 13
stack backtrace:
   0:     0x776f0b5a4c5a - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::heb202b000efba683
   1:     0x776f0be13d66 - core::fmt::write::h4529572b8b32da24
   2:     0x776f0ce1db51 - std::io::Write::write_fmt::h1a906436cb206037
   3:     0x776f0b5a4ab2 - std::sys::backtrace::BacktraceLock::print::h934abc86fa2dd260
   4:     0x776f0b5a6faa - std::panicking::default_hook::{{closure}}::hfd4bbe50128406cd
   5:     0x776f0b5a6df3 - std::panicking::default_hook::h25fd19fcd22c2e04
   6:     0x776f0a6f9a68 - std[70002648da4681c1]::panicking::update_hook::<alloc[334d4c3039138aa]::boxed::Box<rustc_driver_impl[2cc745b14baadf]::install_ice_hook::{closure#0}>>::{closure#0}
   7:     0x776f0b5a7768 - std::panicking::rust_panic_with_hook::h3f6d3ded85336e6b
   8:     0x776f0b5a745a - std::panicking::begin_panic_handler::{{closure}}::h4686f34f41f48fef
   9:     0x776f0b5a50f9 - std::sys::backtrace::__rust_end_short_backtrace::h4d0c634afae53cc6
  10:     0x776f0b5a711d - rust_begin_unwind
  11:     0x776f081cf0c0 - core::panicking::panic_fmt::h5928a9348ea2bb6c
  12:     0x776f09f20c16 - core::panicking::panic_bounds_check::ha0907f8c63a361ab
  13:     0x776f0c076229 - rustc_query_impl[98026ab69133ca5a]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[98026ab69133ca5a]::query_impl::local_def_id_to_hir_id::dynamic_query::{closure#2}::{closure#0}, rustc_middle[4552a92c16cacd81]::query::erase::Erased<[u8; 8usize]>>
  14:     0x776f0c0759f6 - rustc_query_system[c5a9321c1b201b0d]::query::plumbing::try_execute_query::<rustc_query_impl[98026ab69133ca5a]::DynamicConfig<rustc_data_structures[41b15b2b138651fb]::vec_cache::VecCache<rustc_span[5501a71f8d28de35]::def_id::LocalDefId, rustc_middle[4552a92c16cacd81]::query::erase::Erased<[u8; 8usize]>, rustc_query_system[c5a9321c1b201b0d]::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl[98026ab69133ca5a]::plumbing::QueryCtxt, false>
  15:     0x776f0c07544f - rustc_query_impl[98026ab69133ca5a]::query_impl::local_def_id_to_hir_id::get_query_non_incr::__rust_end_short_backtrace
  16:     0x776f0d510cf0 - rustc_middle[4552a92c16cacd81]::query::plumbing::query_get_at::<rustc_data_structures[41b15b2b138651fb]::vec_cache::VecCache<rustc_span[5501a71f8d28de35]::def_id::LocalDefId, rustc_middle[4552a92c16cacd81]::query::erase::Erased<[u8; 8usize]>, rustc_query_system[c5a9321c1b201b0d]::dep_graph::graph::DepNodeIndex>>.cold
  17:     0x776f0ab86c3e - <rustc_middle[4552a92c16cacd81]::ty::context::TyCtxt>::has_attr::<rustc_span[5501a71f8d28de35]::def_id::DefId>
  18:     0x776f0ac0c7e9 - <rustc_lint[7d30a3ff3ade0185]::internal::Diagnostics as rustc_lint[7d30a3ff3ade0185]::passes::LateLintPass>::check_expr
  19:     0x776f0ac0ddd5 - <rustc_lint[7d30a3ff3ade0185]::late::LateContextAndPass<rustc_lint[7d30a3ff3ade0185]::late::RuntimeCombinedLateLintPass> as rustc_hir[5766cc08b8b964b9]::intravisit::Visitor>::visit_expr::{closure#0}
  20:     0x776f0ac0dc7d - <rustc_lint[7d30a3ff3ade0185]::late::LateContextAndPass<rustc_lint[7d30a3ff3ade0185]::late::RuntimeCombinedLateLintPass> as rustc_hir[5766cc08b8b964b9]::intravisit::Visitor>::visit_expr
  21:     0x776f0ac0eba8 - <rustc_lint[7d30a3ff3ade0185]::late::LateContextAndPass<rustc_lint[7d30a3ff3ade0185]::late::RuntimeCombinedLateLintPass> as rustc_hir[5766cc08b8b964b9]::intravisit::Visitor>::visit_block
  22:     0x776f0ac0e5ed - <rustc_lint[7d30a3ff3ade0185]::late::LateContextAndPass<rustc_lint[7d30a3ff3ade0185]::late::RuntimeCombinedLateLintPass> as rustc_hir[5766cc08b8b964b9]::intravisit::Visitor>::visit_expr::{closure#0}
  23:     0x776f0ac0dc7d - <rustc_lint[7d30a3ff3ade0185]::late::LateContextAndPass<rustc_lint[7d30a3ff3ade0185]::late::RuntimeCombinedLateLintPass> as rustc_hir[5766cc08b8b964b9]::intravisit::Visitor>::visit_expr
  24:     0x776f0ac0e1db - <rustc_lint[7d30a3ff3ade0185]::late::LateContextAndPass<rustc_lint[7d30a3ff3ade0185]::late::RuntimeCombinedLateLintPass> as rustc_hir[5766cc08b8b964b9]::intravisit::Visitor>::visit_expr::{closure#0}
  25:     0x776f0ac0dc7d - <rustc_lint[7d30a3ff3ade0185]::late::LateContextAndPass<rustc_lint[7d30a3ff3ade0185]::late::RuntimeCombinedLateLintPass> as rustc_hir[5766cc08b8b964b9]::intravisit::Visitor>::visit_expr
  26:     0x776f0ab90949 - rustc_hir[5766cc08b8b964b9]::intravisit::walk_block::<rustc_lint[7d30a3ff3ade0185]::late::LateContextAndPass<rustc_lint[7d30a3ff3ade0185]::late::RuntimeCombinedLateLintPass>>
  27:     0x776f0ac0eba8 - <rustc_lint[7d30a3ff3ade0185]::late::LateContextAndPass<rustc_lint[7d30a3ff3ade0185]::late::RuntimeCombinedLateLintPass> as rustc_hir[5766cc08b8b964b9]::intravisit::Visitor>::visit_block
  28:     0x776f0ac0e5ed - <rustc_lint[7d30a3ff3ade0185]::late::LateContextAndPass<rustc_lint[7d30a3ff3ade0185]::late::RuntimeCombinedLateLintPass> as rustc_hir[5766cc08b8b964b9]::intravisit::Visitor>::visit_expr::{closure#0}
  29:     0x776f0ac0dc7d - <rustc_lint[7d30a3ff3ade0185]::late::LateContextAndPass<rustc_lint[7d30a3ff3ade0185]::late::RuntimeCombinedLateLintPass> as rustc_hir[5766cc08b8b964b9]::intravisit::Visitor>::visit_expr
  30:     0x776f0ac0e39b - <rustc_lint[7d30a3ff3ade0185]::late::LateContextAndPass<rustc_lint[7d30a3ff3ade0185]::late::RuntimeCombinedLateLintPass> as rustc_hir[5766cc08b8b964b9]::intravisit::Visitor>::visit_expr::{closure#0}
  31:     0x776f0ac0dc7d - <rustc_lint[7d30a3ff3ade0185]::late::LateContextAndPass<rustc_lint[7d30a3ff3ade0185]::late::RuntimeCombinedLateLintPass> as rustc_hir[5766cc08b8b964b9]::intravisit::Visitor>::visit_expr
  32:     0x776f0ab90949 - rustc_hir[5766cc08b8b964b9]::intravisit::walk_block::<rustc_lint[7d30a3ff3ade0185]::late::LateContextAndPass<rustc_lint[7d30a3ff3ade0185]::late::RuntimeCombinedLateLintPass>>
  33:     0x776f0ac0eba8 - <rustc_lint[7d30a3ff3ade0185]::late::LateContextAndPass<rustc_lint[7d30a3ff3ade0185]::late::RuntimeCombinedLateLintPass> as rustc_hir[5766cc08b8b964b9]::intravisit::Visitor>::visit_block
  34:     0x776f0ac0e5ed - <rustc_lint[7d30a3ff3ade0185]::late::LateContextAndPass<rustc_lint[7d30a3ff3ade0185]::late::RuntimeCombinedLateLintPass> as rustc_hir[5766cc08b8b964b9]::intravisit::Visitor>::visit_expr::{closure#0}
  35:     0x776f0ac0dc7d - <rustc_lint[7d30a3ff3ade0185]::late::LateContextAndPass<rustc_lint[7d30a3ff3ade0185]::late::RuntimeCombinedLateLintPass> as rustc_hir[5766cc08b8b964b9]::intravisit::Visitor>::visit_expr
  36:     0x776f0ac0df32 - <rustc_lint[7d30a3ff3ade0185]::late::LateContextAndPass<rustc_lint[7d30a3ff3ade0185]::late::RuntimeCombinedLateLintPass> as rustc_hir[5766cc08b8b964b9]::intravisit::Visitor>::visit_expr::{closure#0}
  37:     0x776f0ac0dc7d - <rustc_lint[7d30a3ff3ade0185]::late::LateContextAndPass<rustc_lint[7d30a3ff3ade0185]::late::RuntimeCombinedLateLintPass> as rustc_hir[5766cc08b8b964b9]::intravisit::Visitor>::visit_expr
  38:     0x776f0ac0eba8 - <rustc_lint[7d30a3ff3ade0185]::late::LateContextAndPass<rustc_lint[7d30a3ff3ade0185]::late::RuntimeCombinedLateLintPass> as rustc_hir[5766cc08b8b964b9]::intravisit::Visitor>::visit_block
  39:     0x776f0ac0e5ed - <rustc_lint[7d30a3ff3ade0185]::late::LateContextAndPass<rustc_lint[7d30a3ff3ade0185]::late::RuntimeCombinedLateLintPass> as rustc_hir[5766cc08b8b964b9]::intravisit::Visitor>::visit_expr::{closure#0}
  40:     0x776f0ac0dc7d - <rustc_lint[7d30a3ff3ade0185]::late::LateContextAndPass<rustc_lint[7d30a3ff3ade0185]::late::RuntimeCombinedLateLintPass> as rustc_hir[5766cc08b8b964b9]::intravisit::Visitor>::visit_expr
  41:     0x776f0ac0dba3 - <rustc_lint[7d30a3ff3ade0185]::late::LateContextAndPass<rustc_lint[7d30a3ff3ade0185]::late::RuntimeCombinedLateLintPass> as rustc_hir[5766cc08b8b964b9]::intravisit::Visitor>::visit_nested_body
  42:     0x776f0ac0e6fe - <rustc_lint[7d30a3ff3ade0185]::late::LateContextAndPass<rustc_lint[7d30a3ff3ade0185]::late::RuntimeCombinedLateLintPass> as rustc_hir[5766cc08b8b964b9]::intravisit::Visitor>::visit_fn
  43:     0x776f0ac0e184 - <rustc_lint[7d30a3ff3ade0185]::late::LateContextAndPass<rustc_lint[7d30a3ff3ade0185]::late::RuntimeCombinedLateLintPass> as rustc_hir[5766cc08b8b964b9]::intravisit::Visitor>::visit_expr::{closure#0}
  44:     0x776f0ac0dc7d - <rustc_lint[7d30a3ff3ade0185]::late::LateContextAndPass<rustc_lint[7d30a3ff3ade0185]::late::RuntimeCombinedLateLintPass> as rustc_hir[5766cc08b8b964b9]::intravisit::Visitor>::visit_expr
  45:     0x776f0ac0dba3 - <rustc_lint[7d30a3ff3ade0185]::late::LateContextAndPass<rustc_lint[7d30a3ff3ade0185]::late::RuntimeCombinedLateLintPass> as rustc_hir[5766cc08b8b964b9]::intravisit::Visitor>::visit_nested_body
  46:     0x776f0ac0e6fe - <rustc_lint[7d30a3ff3ade0185]::late::LateContextAndPass<rustc_lint[7d30a3ff3ade0185]::late::RuntimeCombinedLateLintPass> as rustc_hir[5766cc08b8b964b9]::intravisit::Visitor>::visit_fn
  47:     0x776f0abf914b - <rustc_lint[7d30a3ff3ade0185]::late::LateContextAndPass<rustc_lint[7d30a3ff3ade0185]::late::RuntimeCombinedLateLintPass> as rustc_hir[5766cc08b8b964b9]::intravisit::Visitor>::visit_nested_item
  48:     0x776f0c0960c0 - rustc_lint[7d30a3ff3ade0185]::lint_mod
  49:     0x776f0c095b6b - rustc_query_impl[98026ab69133ca5a]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[98026ab69133ca5a]::query_impl::lint_mod::dynamic_query::{closure#2}::{closure#0}, rustc_middle[4552a92c16cacd81]::query::erase::Erased<[u8; 0usize]>>
  50:     0x776f0ce0ba01 - rustc_query_system[c5a9321c1b201b0d]::query::plumbing::try_execute_query::<rustc_query_impl[98026ab69133ca5a]::DynamicConfig<rustc_query_system[c5a9321c1b201b0d]::query::caches::DefaultCache<rustc_span[5501a71f8d28de35]::def_id::LocalModDefId, rustc_middle[4552a92c16cacd81]::query::erase::Erased<[u8; 0usize]>>, false, false, false>, rustc_query_impl[98026ab69133ca5a]::plumbing::QueryCtxt, false>
  51:     0x776f0ce09bd8 - rustc_query_impl[98026ab69133ca5a]::query_impl::lint_mod::get_query_non_incr::__rust_end_short_backtrace
  52:     0x776f0ce097c2 - rustc_lint[7d30a3ff3ade0185]::late::check_crate::{closure#1}
  53:     0x776f0ce09338 - rustc_lint[7d30a3ff3ade0185]::late::check_crate
  54:     0x776f0ce0cb5d - rustc_interface[cf66c2394d3c8572]::passes::analysis
  55:     0x776f0ce0c8ef - rustc_query_impl[98026ab69133ca5a]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[98026ab69133ca5a]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[4552a92c16cacd81]::query::erase::Erased<[u8; 0usize]>>
  56:     0x776f0ce41015 - rustc_query_system[c5a9321c1b201b0d]::query::plumbing::try_execute_query::<rustc_query_impl[98026ab69133ca5a]::DynamicConfig<rustc_query_system[c5a9321c1b201b0d]::query::caches::SingleCache<rustc_middle[4552a92c16cacd81]::query::erase::Erased<[u8; 0usize]>>, false, false, false>, rustc_query_impl[98026ab69133ca5a]::plumbing::QueryCtxt, false>
  57:     0x776f0ce40d4e - rustc_query_impl[98026ab69133ca5a]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  58:     0x776f0ceb61b4 - rustc_interface[cf66c2394d3c8572]::interface::run_compiler::<(), rustc_driver_impl[2cc745b14baadf]::run_compiler::{closure#0}>::{closure#1}
  59:     0x776f0cd685db - std[70002648da4681c1]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[cf66c2394d3c8572]::util::run_in_thread_with_globals<rustc_interface[cf66c2394d3c8572]::util::run_in_thread_pool_with_globals<rustc_interface[cf66c2394d3c8572]::interface::run_compiler<(), rustc_driver_impl[2cc745b14baadf]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
  60:     0x776f0cd68a90 - <<std[70002648da4681c1]::thread::Builder>::spawn_unchecked_<rustc_interface[cf66c2394d3c8572]::util::run_in_thread_with_globals<rustc_interface[cf66c2394d3c8572]::util::run_in_thread_pool_with_globals<rustc_interface[cf66c2394d3c8572]::interface::run_compiler<(), rustc_driver_impl[2cc745b14baadf]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core[3b8d2fc2756ea0bb]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  61:     0x776f0cd6a06f - std::sys::pal::unix::thread::Thread::new::thread_start::hdeaa41b2ac9b4ad7
  62:     0x776f06ea339d - <unknown>
  63:     0x776f06f2849c - <unknown>
  64:                0x0 - <unknown>

error: 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: please make sure that you have updated to the latest nightly

note: rustc 1.85.0-nightly (4790a435c 2024-12-15) running on x86_64-unknown-linux-gnu

note: compiler flags: -Z unstable-options --crate-type lib -Z dump-mir-dir=dir

query stack during panic:
#0 [local_def_id_to_hir_id] getting HIR ID of `async_closure::{closure#0}::{closure#0}::{closure#1}`
#1 [lint_mod] linting top-level module
end of query stack

[matthiaskrgr]

//@compile-flags: -Zunstable-options --edition=2021 --crate-type=lib

#![feature(async_closure)]
pub async fn async_closure(x: &mut i32) {
    let c = async move || {
        *x += 1;
    };
    call_once(c).await;
}

fn call_once<T>(f: impl FnOnce() -> T) -> T {
    f()
}

bisects to #128506