ICE: `expected usize, got Const`

[matthiaskrgr]

Code

#![feature(generic_const_exprs)]

pub async fn something(path: &[[usize; N_ISLANDS]; PrivateStruct]) -> usize {
    match path {
        [] | _ => 0,
    }
}

pub fn main() {}

Meta

rustc --version --verbose:

rustc 1.72.0-nightly (22e9fe644 2023-06-23)
binary: rustc
commit-hash: 22e9fe644ea710eec50cb0aabcae7fa8dd9fd675
commit-date: 2023-06-23
host: x86_64-unknown-linux-gnu
release: 1.72.0-nightly
LLVM version: 16.0.5

Error output

error[E0670]: `async fn` is not permitted in Rust 2015
 --> 063C62043B0E0550CF8DB5A3E283C6D530D674D10E7B87DEBB6545F792710536.rs:3:5
  |
3 | pub async fn something(path: &[[usize; N_ISLANDS]; PrivateStruct]) -> usize {
  |     ^^^^^ to use `async fn`, switch to Rust 2018 or later
  |
  = help: pass `--edition 2021` to `rustc`
  = note: for more on editions, read https://doc.rust-lang.org/edition-guide

error[E0425]: cannot find value `N_ISLANDS` in this scope
 --> 063C62043B0E0550CF8DB5A3E283C6D530D674D10E7B87DEBB6545F792710536.rs:3:40
  |
3 | pub async fn something(path: &[[usize; N_ISLANDS]; PrivateStruct]) -> usize {
  |                                        ^^^^^^^^^ not found in this scope

error[E0425]: cannot find value `PrivateStruct` in this scope
 --> 063C62043B0E0550CF8DB5A3E283C6D530D674D10E7B87DEBB6545F792710536.rs:3:52
  |
3 | pub async fn something(path: &[[usize; N_ISLANDS]; PrivateStruct]) -> usize {
  |                                                    ^^^^^^^^^^^^^ not found in this scope

warning: the feature `generic_const_exprs` is incomplete and may not be safe to use and/or cause compiler crashes
 --> 063C62043B0E0550CF8DB5A3E283C6D530D674D10E7B87DEBB6545F792710536.rs:1:12
  |
1 | #![feature(generic_const_exprs)]
  |            ^^^^^^^^^^^^^^^^^^^
  |
  = note: see issue #76560 <https://github.com/rust-lang/rust/issues/76560> for more information
  = note: `#[warn(incomplete_features)]` on by default

Backtrace

``` error: internal compiler error: /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/compiler/rustc_middle/src/ty/consts.rs:238:32: expected usize, got Const { ty: usize, kind: Unevaluated([], DefId(0:5 ~ 063C62043B0E0550CF8DB5A3E283C6D530D674D10E7B87DEBB6545F792710536[8e5e]::something::{constant#1})) } thread 'rustc' panicked at 'Box', /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/compiler/rustc_errors/src/lib.rs:1650:9 stack backtrace: 0: 0x7fc4ff041e31 - std::backtrace_rs::backtrace::libunwind::trace::h45c8b5b393354aaa at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5 1: 0x7fc4ff041e31 - std::backtrace_rs::backtrace::trace_unsynchronized::hc5cde6aeff03cc23 at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5 2: 0x7fc4ff041e31 - std::sys_common::backtrace::_print_fmt::h86fd79bdeff6c899 at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/std/src/sys_common/backtrace.rs:65:5 3: 0x7fc4ff041e31 - ::fmt::h0f1168665e8c8865 at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/std/src/sys_common/backtrace.rs:44:22 4: 0x7fc4ff0a35df - core::fmt::rt::Argument::fmt::hfed1a51422c978b7 at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/core/src/fmt/rt.rs:138:9 5: 0x7fc4ff0a35df - core::fmt::write::h4dfc2a0c62cf3fd6 at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/core/src/fmt/mod.rs:1094:21 6: 0x7fc4ff034967 - std::io::Write::write_fmt::ha45cc30dd6a81686 at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/std/src/io/mod.rs:1714:15 7: 0x7fc4ff041c45 - std::sys_common::backtrace::_print::h14294ae8d055d04e at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/std/src/sys_common/backtrace.rs:47:5 8: 0x7fc4ff041c45 - std::sys_common::backtrace::print::hf007ea148056754d at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/std/src/sys_common/backtrace.rs:34:9 9: 0x7fc4ff0449f3 - std::panicking::default_hook::{{closure}}::h12f0e86c17019fae at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/std/src/panicking.rs:269:22 10: 0x7fc4ff044784 - std::panicking::default_hook::h3e363e70e8823128 at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/std/src/panicking.rs:288:9 11: 0x7fc4fde03eab - rustc_driver_impl[1ee18bc64acaad37]::install_ice_hook::{closure#0} 12: 0x7fc4ff04521e - as core::ops::function::Fn>::call::h6345ba7ef09e0a3b at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/alloc/src/boxed.rs:2007:9 13: 0x7fc4ff04521e - std::panicking::rust_panic_with_hook::he3112cb9ec41f5a5 at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/std/src/panicking.rs:709:13 14: 0x7fc4fe3d4581 - std[590ba7ead67831d4]::panicking::begin_panic::::{closure#0} 15: 0x7fc4fe3d1856 - std[590ba7ead67831d4]::sys_common::backtrace::__rust_end_short_backtrace::::{closure#0}, !> 16: 0x7fc4fe3c2ce6 - std[590ba7ead67831d4]::panicking::begin_panic:: 17: 0x7fc4fe325a14 - ::bug:: 18: 0x7fc4fe325896 - ::bug:: 19: 0x7fc4fe34870c - rustc_middle[aeb3147772634dcd]::util::bug::opt_span_bug_fmt::::{closure#0} 20: 0x7fc4fe34776a - rustc_middle[aeb3147772634dcd]::ty::context::tls::with_opt::::{closure#0}, !>::{closure#0} 21: 0x7fc4fe34773a - rustc_middle[aeb3147772634dcd]::ty::context::tls::with_context_opt::::{closure#0}, !>::{closure#0}, !> 22: 0x7fc4fc1c42ad - rustc_middle[aeb3147772634dcd]::util::bug::bug_fmt 23: 0x7fc4fcf40615 - ::prefix_slice_suffix 24: 0x7fc4fcf44bc7 - ::simplify_candidate 25: 0x7fc4fcf4092e - >, ::create_or_subcandidates::{closure#0}> as core[db7c5f9f8e26b951]::iter::traits::iterator::Iterator>::fold::<(), core[db7c5f9f8e26b951]::iter::traits::iterator::Iterator::for_each::call>::extend_trusted>, ::create_or_subcandidates::{closure#0}>>::{closure#0}>::{closure#0}> 26: 0x7fc4fcf3ff95 - as alloc[2c2f5c796e500044]::vec::spec_from_iter::SpecFromIter>, ::create_or_subcandidates::{closure#0}>>>::from_iter 27: 0x7fc4fcf3c06e - ::match_candidates 28: 0x7fc4fc22b377 - ::lower_match_tree 29: 0x7fc4fc208540 - ::expr_into_dest 30: 0x7fc4fc2064eb - ::expr_into_dest 31: 0x7fc4fc237ddc - ::ast_block_stmts 32: 0x7fc4fc22a1d3 - ::ast_block 33: 0x7fc4fc2073c2 - ::expr_into_dest 34: 0x7fc4fc2064eb - ::expr_into_dest 35: 0x7fc4fc2064eb - ::expr_into_dest 36: 0x7fc4fc208c9d - ::expr_into_dest 37: 0x7fc4fc2064eb - ::expr_into_dest 38: 0x7fc4fc237ddc - ::ast_block_stmts 39: 0x7fc4fc22a1d3 - ::ast_block 40: 0x7fc4fc2073c2 - ::expr_into_dest 41: 0x7fc4fc2064eb - ::expr_into_dest 42: 0x7fc4fc2064eb - ::expr_into_dest 43: 0x7fc4fccedef5 - rustc_mir_build[c1d3f5d6f149c6f6]::build::mir_built 44: 0x7fc4fbe32e6c - rustc_query_impl[30672f8f3d90a755]::plumbing::__rust_begin_short_backtrace::> 45: 0x7fc4fbe32e4e - >::call_once 46: 0x7fc4fbf265ad - rustc_query_system[29d9bde875297da0]::query::plumbing::try_execute_query::>, false, false, false>, rustc_query_impl[30672f8f3d90a755]::plumbing::QueryCtxt, false> 47: 0x7fc4fd789dc1 - rustc_query_impl[30672f8f3d90a755]::query_impl::mir_built::get_query_non_incr::__rust_end_short_backtrace 48: 0x7fc4fcf73de4 - rustc_mir_transform[ea407ab7eecac49d]::check_unsafety::unsafety_check_result 49: 0x7fc4fbe32eac - rustc_query_impl[30672f8f3d90a755]::plumbing::__rust_begin_short_backtrace::> 50: 0x7fc4fbe32e8e - >::call_once 51: 0x7fc4fbf265ad - rustc_query_system[29d9bde875297da0]::query::plumbing::try_execute_query::>, false, false, false>, rustc_query_impl[30672f8f3d90a755]::plumbing::QueryCtxt, false> 52: 0x7fc4fd784db1 - rustc_query_impl[30672f8f3d90a755]::query_impl::unsafety_check_result::get_query_non_incr::__rust_end_short_backtrace 53: 0x7fc4fcf77394 - rustc_mir_transform[ea407ab7eecac49d]::check_unsafety::unsafety_check_result 54: 0x7fc4fbe32eac - rustc_query_impl[30672f8f3d90a755]::plumbing::__rust_begin_short_backtrace::> 55: 0x7fc4fbe32e8e - >::call_once 56: 0x7fc4fbf265ad - rustc_query_system[29d9bde875297da0]::query::plumbing::try_execute_query::>, false, false, false>, rustc_query_impl[30672f8f3d90a755]::plumbing::QueryCtxt, false> 57: 0x7fc4fd784db1 - rustc_query_impl[30672f8f3d90a755]::query_impl::unsafety_check_result::get_query_non_incr::__rust_end_short_backtrace 58: 0x7fc4fd1345e4 - rustc_mir_transform[ea407ab7eecac49d]::mir_const 59: 0x7fc4fbe3e3ce - rustc_query_impl[30672f8f3d90a755]::plumbing::__rust_begin_short_backtrace::> 60: 0x7fc4fbe3e39e - >::call_once 61: 0x7fc4fbf265ad - rustc_query_system[29d9bde875297da0]::query::plumbing::try_execute_query::>, false, false, false>, rustc_query_impl[30672f8f3d90a755]::plumbing::QueryCtxt, false> 62: 0x7fc4fd7842a1 - rustc_query_impl[30672f8f3d90a755]::query_impl::mir_const::get_query_non_incr::__rust_end_short_backtrace 63: 0x7fc4fc01258a - rustc_mir_transform[ea407ab7eecac49d]::mir_promoted 64: 0x7fc4fbe32f01 - rustc_query_impl[30672f8f3d90a755]::plumbing::__rust_begin_short_backtrace::> 65: 0x7fc4fc6cc5aa - rustc_query_system[29d9bde875297da0]::query::plumbing::try_execute_query::>, false, false, false>, rustc_query_impl[30672f8f3d90a755]::plumbing::QueryCtxt, false> 66: 0x7fc4fd77f367 - rustc_query_impl[30672f8f3d90a755]::query_impl::mir_promoted::get_query_non_incr::__rust_end_short_backtrace 67: 0x7fc4fc702a2c - rustc_borrowck[5b525c22e5b16615]::mir_borrowck 68: 0x7fc4fbe3e42e - rustc_query_impl[30672f8f3d90a755]::plumbing::__rust_begin_short_backtrace::> 69: 0x7fc4fbe3e3fe - >::call_once 70: 0x7fc4fbf265ad - rustc_query_system[29d9bde875297da0]::query::plumbing::try_execute_query::>, false, false, false>, rustc_query_impl[30672f8f3d90a755]::plumbing::QueryCtxt, false> 71: 0x7fc4fd7850f1 - rustc_query_impl[30672f8f3d90a755]::query_impl::mir_borrowck::get_query_non_incr::__rust_end_short_backtrace 72: 0x7fc4fcfa6e3e - rustc_hir_analysis[bed39c5e84d3e350]::collect::type_of::opaque::find_opaque_ty_constraints_for_rpit 73: 0x7fc4fcfa3a04 - rustc_hir_analysis[bed39c5e84d3e350]::collect::type_of::type_of 74: 0x7fc4fbf52a33 - rustc_query_impl[30672f8f3d90a755]::plumbing::__rust_begin_short_backtrace::> 75: 0x7fc4fbf529f0 - >::call_once 76: 0x7fc4fbe3d515 - rustc_query_system[29d9bde875297da0]::query::plumbing::try_execute_query::>, false, false, false>, rustc_query_impl[30672f8f3d90a755]::plumbing::QueryCtxt, false> 77: 0x7fc4fd783d73 - rustc_query_impl[30672f8f3d90a755]::query_impl::type_of::get_query_non_incr::__rust_end_short_backtrace 78: 0x7fc4fcddad50 - rustc_middle[aeb3147772634dcd]::query::plumbing::query_get_at::>> 79: 0x7fc4fcdd4ca4 - rustc_hir_analysis[bed39c5e84d3e350]::check::check::check_mod_item_types 80: 0x7fc4fcad91fc - rustc_query_impl[30672f8f3d90a755]::plumbing::__rust_begin_short_backtrace::> 81: 0x7fc4fcad91de - >::call_once 82: 0x7fc4fc4f518f - rustc_query_system[29d9bde875297da0]::query::plumbing::try_execute_query::>, false, false, false>, rustc_query_impl[30672f8f3d90a755]::plumbing::QueryCtxt, false> 83: 0x7fc4fd76fc04 - rustc_query_impl[30672f8f3d90a755]::query_impl::check_mod_item_types::get_query_non_incr::__rust_end_short_backtrace 84: 0x7fc4fd298f57 - ::for_each_module:: 85: 0x7fc4fd29832d - ::time::<(), rustc_hir_analysis[bed39c5e84d3e350]::check_crate::{closure#6}> 86: 0x7fc4fd296ff7 - rustc_hir_analysis[bed39c5e84d3e350]::check_crate 87: 0x7fc4fd28fb6a - rustc_interface[3e44238a9783f3c8]::passes::analysis 88: 0x7fc4fd2dc83a - rustc_query_impl[30672f8f3d90a755]::plumbing::__rust_begin_short_backtrace::> 89: 0x7fc4fd2dc829 - >::call_once 90: 0x7fc4fd471c18 - rustc_query_system[29d9bde875297da0]::query::plumbing::try_execute_query::>, false, false, false>, rustc_query_impl[30672f8f3d90a755]::plumbing::QueryCtxt, false> 91: 0x7fc4fd4719e9 - rustc_query_impl[30672f8f3d90a755]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace 92: 0x7fc4fd428485 - ::enter::> 93: 0x7fc4fd003f4b - ::enter::, rustc_span[8155bebf48a1eb91]::ErrorGuaranteed>> 94: 0x7fc4fcfffd99 - rustc_span[8155bebf48a1eb91]::set_source_map::, rustc_interface[3e44238a9783f3c8]::interface::run_compiler, rustc_driver_impl[1ee18bc64acaad37]::run_compiler::{closure#1}>::{closure#0}::{closure#0}> 95: 0x7fc4fcfff8c5 - >::set::, rustc_driver_impl[1ee18bc64acaad37]::run_compiler::{closure#1}>::{closure#0}, core[db7c5f9f8e26b951]::result::Result<(), rustc_span[8155bebf48a1eb91]::ErrorGuaranteed>> 96: 0x7fc4fcffeee6 - std[590ba7ead67831d4]::sys_common::backtrace::__rust_begin_short_backtrace::, rustc_driver_impl[1ee18bc64acaad37]::run_compiler::{closure#1}>::{closure#0}, core[db7c5f9f8e26b951]::result::Result<(), rustc_span[8155bebf48a1eb91]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[db7c5f9f8e26b951]::result::Result<(), rustc_span[8155bebf48a1eb91]::ErrorGuaranteed>> 97: 0x7fc4fd673945 - <::spawn_unchecked_, rustc_driver_impl[1ee18bc64acaad37]::run_compiler::{closure#1}>::{closure#0}, core[db7c5f9f8e26b951]::result::Result<(), rustc_span[8155bebf48a1eb91]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[db7c5f9f8e26b951]::result::Result<(), rustc_span[8155bebf48a1eb91]::ErrorGuaranteed>>::{closure#1} as core[db7c5f9f8e26b951]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0} 98: 0x7fc4ff04f695 - as core::ops::function::FnOnce>::call_once::h2e6f8aee19cb9bca at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/alloc/src/boxed.rs:1993:9 99: 0x7fc4ff04f695 - as core::ops::function::FnOnce>::call_once::h4548c5cdbeb5a136 at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/alloc/src/boxed.rs:1993:9 100: 0x7fc4ff04f695 - std::sys::unix::thread::Thread::new::thread_start::h57734a91bfb8a041 at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/std/src/sys/unix/thread.rs:108:17 101: 0x7fc4faa9d44b - 102: 0x7fc4fab20e40 - 103: 0x0 - 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 1.72.0-nightly (22e9fe644 2023-06-23) running on x86_64-unknown-linux-gnu query stack during panic: #0 [mir_built] building MIR for `something::{closure#0}` #1 [unsafety_check_result] unsafety-checking `something::{closure#0}` #2 [unsafety_check_result] unsafety-checking `something` #3 [mir_const] preparing `something` for borrow checking #4 [mir_promoted] promoting constants in MIR for `something` #5 [mir_borrowck] borrow-checking `something` #6 [type_of] computing type of `something::{opaque#0}` #7 [check_mod_item_types] checking item types in top-level module #8 [analysis] running analysis passes on this crate end of query stack error: aborting due to 4 previous errors; 1 warning emitted Some errors have detailed explanations: E0425, E0670. For more information about an error, try `rustc --explain E0425`. ```

[BoxyUwU]

cc @clubby789

[clubby789]

This also ICEs on stable with the same error, so I don't think this is related to any of my recent changes at a glance. Having a look at it though

[matthiaskrgr]

Regression in nightly-2021-09-01 commit[0] 2021-08-30: Auto merge of #88466 - sexxi-goose:issue-88372, r=nikomatsakis commit[1] 2021-08-30: Auto merge of #88369 - lcnr:cec-rename, r=oli-obk commit[2] 2021-08-31: Auto merge of #88100 - HTG-YT:edition2021-compopt-stabilization, r=m-ou-se commit[3] 2021-08-31: Auto merge of #88414 - Aaron1011:guess-foreign-head-span, r=estebank commit[4] 2021-08-31: Auto merge of #88467 - sexxi-goose:issue-88431, r=nikomatsakis commit[5] 2021-08-31: Auto merge of #88491 - RalfJung:miri, r=RalfJung commit[6] 2021-08-31: Auto merge of #88527 - m-ou-se:rollup-az6xtc5, r=m-ou-se commit[7] 2021-08-31: Auto merge of #88535 - m-ou-se:rollup-jeusxbo, r=m-ou-se commit[8] 2021-08-31: Auto merge of #88506 - Mark-Simulacrum:fix-rlibs, r=ehuss

[clubby789]

update const generics feature gates

I suspect that might be a false positive bisect?

[matthiaskrgr]

ah meh, probably, if the feature gate was renamed or something, the code with the "new" feature gate might no longer trigger the ice once needed the old feature gate -_-

[syvb]

Bisected to nightly-2022-11-27, probably caused by #99798.

cargo-bisect-rustc output

``` commit[0] 2022-11-25: Auto merge of #104902 - matthiaskrgr:rollup-oo27a4u, r=matthiaskrgr commit[1] 2022-11-25: Auto merge of #99798 - JulianKnodt:ac1, r=BoxyUwU commit[2] 2022-11-26: Auto merge of #104431 - alistair23:alistair/rv64-profiler, r=Mark-Simulacrum commit[3] 2022-11-26: Auto merge of #104730 - petrochenkov:modchild5, r=cjgillot commit[4] 2022-11-26: Auto merge of #103556 - clubby789:specialize-option-partial-eq, r=scottmcm commit[5] 2022-11-26: Auto merge of #104935 - matthiaskrgr:rollup-nuca86l, r=matthiaskrgr commit[6] 2022-11-26: Auto merge of #104731 - compiler-errors:early-binder-iter-size-hint, r=cjgillot commit[7] 2022-11-26: Auto merge of #104945 - GuillaumeGomez:rollup-ygzbpbe, r=GuillaumeGomez ```