assertion left == right failed: layout mismatch for result of SubWithOverflow

[jjl9807]

Code

#![feature(generic_const_exprs)]

type Arr<const N: usize> = [u8; N - 1];

fn test<const N: i64>() -> Arr<N>
where
    [u8; N - 1]: Sized,
{
    todo!()
}

fn main() {
    test::<0>();
}

Meta

rustc --version --verbose:

rustc 1.88.0-nightly (e2014e876 2025-04-01)
binary: rustc
commit-hash: e2014e876e3efaa69bf51c19579adb16c3df5f81
commit-date: 2025-04-01
host: x86_64-unknown-linux-gnu
release: 1.88.0-nightly
LLVM version: 20.1.1

Error output

thread 'rustc' panicked at compiler/rustc_const_eval/src/interpret/step.rs:191:17:
assertion `left == right` failed: layout mismatch for result of SubWithOverflow

Backtrace

thread 'rustc' panicked at compiler/rustc_const_eval/src/interpret/step.rs:191:17:
assertion `left == right` failed: layout mismatch for result of SubWithOverflow
  left: TyAndLayout { ty: (i64, bool), layout: Layout { size: Size(16 bytes), align: AbiAndPrefAlign { abi: Align(8 bytes), pref: Align(8 bytes) }, backend_repr: ScalarPair(Initialized { value: Int(I64, true), valid_range: 0..=18446744073709551615 }, Initialized { value: Int(I8, false), valid_range: 0..=1 }), fields: Arbitrary { offsets: [Size(0 bytes), Size(8 bytes)], memory_index: [0, 1] }, largest_niche: Some(Niche { offset: Size(8 bytes), value: Int(I8, false), valid_range: 0..=1 }), uninhabited: false, variants: Single { index: 0 }, max_repr_align: None, unadjusted_abi_align: Align(8 bytes), randomization_seed: 4294967303 } }
 right: TyAndLayout { ty: (usize, bool), layout: Layout { size: Size(16 bytes), align: AbiAndPrefAlign { abi: Align(8 bytes), pref: Align(8 bytes) }, backend_repr: ScalarPair(Initialized { value: Int(I64, false), valid_range: 0..=18446744073709551615 }, Initialized { value: Int(I8, false), valid_range: 0..=1 }), fields: Arbitrary { offsets: [Size(0 bytes), Size(8 bytes)], memory_index: [0, 1] }, largest_niche: Some(Niche { offset: Size(8 bytes), value: Int(I8, false), valid_range: 0..=1 }), uninhabited: false, variants: Single { index: 0 }, max_repr_align: None, unadjusted_abi_align: Align(8 bytes), randomization_seed: 8589934599 } }
stack backtrace:
   0:     0x7f6d524cce25 - std::backtrace::Backtrace::create::h38afe53d7dc2ee8a
   1:     0x7f6d50862495 - std::backtrace::Backtrace::force_capture::h23772f3a350b6c5f
   2:     0x7f6d4f8ee79f - std[43c66c29bb2da0cf]::panicking::update_hook::<alloc[9d6af472d28301be]::boxed::Box<rustc_driver_impl[2a6f85d55f84b44d]::install_ice_hook::{closure#1}>>::{closure#0}
   3:     0x7f6d5087bd13 - std::panicking::rust_panic_with_hook::hec08a623892d81df
   4:     0x7f6d5087ba0a - std::panicking::begin_panic_handler::{{closure}}::hb834b9141c0f2230
   5:     0x7f6d50878019 - std::sys::backtrace::__rust_end_short_backtrace::h1dafc29f13d910f2
   6:     0x7f6d5087b6cd - __rustc[e22706cb8dde8ca2]::rust_begin_unwind
   7:     0x7f6d4d29dc90 - core::panicking::panic_fmt::h3e60cc11c74279b0
   8:     0x7f6d4f2ce68a - core::panicking::assert_failed_inner::hc3a4d54eaeabdbdc
   9:     0x7f6d4f82a322 - core[64194c3d1231b2c8]::panicking::assert_failed::<rustc_abi[c759ef77f9aec3cd]::layout::ty::TyAndLayout<rustc_middle[cbfbdec2b42921ad]::ty::Ty>, rustc_abi[c759ef77f9aec3cd]::layout::ty::TyAndLayout<rustc_middle[cbfbdec2b42921ad]::ty::Ty>>
  10:     0x7f6d51f1c317 - <rustc_const_eval[9beadfa2b01a94fc]::interpret::eval_context::InterpCx<rustc_const_eval[9beadfa2b01a94fc]::const_eval::machine::CompileTimeMachine>>::eval_rvalue_into_place
  11:     0x7f6d51ebe70c - rustc_const_eval[9beadfa2b01a94fc]::const_eval::eval_queries::eval_to_allocation_raw_provider
  12:     0x7f6d51ebd24a - rustc_query_impl[514e88206e175c88]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[514e88206e175c88]::query_impl::eval_to_allocation_raw::dynamic_query::{closure#2}::{closure#0}, rustc_middle[cbfbdec2b42921ad]::query::erase::Erased<[u8; 24usize]>>
  13:     0x7f6d51ea26e2 - rustc_query_system[6bf3121dceac80f2]::query::plumbing::try_execute_query::<rustc_query_impl[514e88206e175c88]::DynamicConfig<rustc_query_system[6bf3121dceac80f2]::query::caches::DefaultCache<rustc_middle[cbfbdec2b42921ad]::ty::PseudoCanonicalInput<rustc_middle[cbfbdec2b42921ad]::mir::interpret::GlobalId>, rustc_middle[cbfbdec2b42921ad]::query::erase::Erased<[u8; 24usize]>>, false, false, false>, rustc_query_impl[514e88206e175c88]::plumbing::QueryCtxt, false>
  14:     0x7f6d51ea22b4 - rustc_query_impl[514e88206e175c88]::query_impl::eval_to_allocation_raw::get_query_non_incr::__rust_end_short_backtrace
  15:     0x7f6d51e9cb76 - rustc_const_eval[9beadfa2b01a94fc]::const_eval::valtrees::eval_to_valtree
  16:     0x7f6d51e9c918 - <rustc_const_eval[9beadfa2b01a94fc]::provide::{closure#0} as core[64194c3d1231b2c8]::ops::function::FnOnce<(rustc_middle[cbfbdec2b42921ad]::ty::context::TyCtxt, rustc_middle[cbfbdec2b42921ad]::ty::PseudoCanonicalInput<rustc_middle[cbfbdec2b42921ad]::mir::interpret::GlobalId>)>>::call_once
  17:     0x7f6d51e9c8c2 - rustc_query_impl[514e88206e175c88]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[514e88206e175c88]::query_impl::eval_to_valtree::dynamic_query::{closure#2}::{closure#0}, rustc_middle[cbfbdec2b42921ad]::query::erase::Erased<[u8; 24usize]>>
  18:     0x7f6d51e9c87b - <rustc_query_impl[514e88206e175c88]::query_impl::eval_to_valtree::dynamic_query::{closure#2} as core[64194c3d1231b2c8]::ops::function::FnOnce<(rustc_middle[cbfbdec2b42921ad]::ty::context::TyCtxt, rustc_middle[cbfbdec2b42921ad]::ty::PseudoCanonicalInput<rustc_middle[cbfbdec2b42921ad]::mir::interpret::GlobalId>)>>::call_once
  19:     0x7f6d51ea27c8 - rustc_query_system[6bf3121dceac80f2]::query::plumbing::try_execute_query::<rustc_query_impl[514e88206e175c88]::DynamicConfig<rustc_query_system[6bf3121dceac80f2]::query::caches::DefaultCache<rustc_middle[cbfbdec2b42921ad]::ty::PseudoCanonicalInput<rustc_middle[cbfbdec2b42921ad]::mir::interpret::GlobalId>, rustc_middle[cbfbdec2b42921ad]::query::erase::Erased<[u8; 24usize]>>, false, false, false>, rustc_query_impl[514e88206e175c88]::plumbing::QueryCtxt, false>
  20:     0x7f6d51ea21b4 - rustc_query_impl[514e88206e175c88]::query_impl::eval_to_valtree::get_query_non_incr::__rust_end_short_backtrace
  21:     0x7f6d51ba8080 - <rustc_middle[cbfbdec2b42921ad]::ty::context::TyCtxt>::const_eval_global_id_for_typeck
  22:     0x7f6d51ba7c31 - <rustc_middle[cbfbdec2b42921ad]::ty::context::TyCtxt>::const_eval_resolve_for_typeck
  23:     0x7f6d51ba9a7e - rustc_trait_selection[d9b12b4bf70ffad7]::traits::try_evaluate_const
  24:     0x7f6d52d9d946 - rustc_trait_selection[d9b12b4bf70ffad7]::traits::const_evaluatable::is_const_evaluatable.cold
  25:     0x7f6d51963cad - <rustc_trait_selection[d9b12b4bf70ffad7]::traits::fulfill::FulfillProcessor as rustc_data_structures[af9d6d584b86a654]::obligation_forest::ObligationProcessor>::process_obligation
  26:     0x7f6d51007d29 - <rustc_data_structures[af9d6d584b86a654]::obligation_forest::ObligationForest<rustc_trait_selection[d9b12b4bf70ffad7]::traits::fulfill::PendingPredicateObligation>>::process_obligations::<rustc_trait_selection[d9b12b4bf70ffad7]::traits::fulfill::FulfillProcessor>
  27:     0x7f6d511605d4 - <rustc_hir_typeck[f143b67fdfdef807]::fn_ctxt::FnCtxt>::confirm_builtin_call
  28:     0x7f6d51d475a4 - <rustc_hir_typeck[f143b67fdfdef807]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  29:     0x7f6d51d40776 - <rustc_hir_typeck[f143b67fdfdef807]::fn_ctxt::FnCtxt>::check_expr_block
  30:     0x7f6d51d482c6 - <rustc_hir_typeck[f143b67fdfdef807]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  31:     0x7f6d515b9099 - rustc_hir_typeck[f143b67fdfdef807]::check::check_fn
  32:     0x7f6d515a5fa3 - rustc_hir_typeck[f143b67fdfdef807]::typeck_with_inspect::{closure#0}
  33:     0x7f6d515a4d36 - rustc_query_impl[514e88206e175c88]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[514e88206e175c88]::query_impl::typeck::dynamic_query::{closure#2}::{closure#0}, rustc_middle[cbfbdec2b42921ad]::query::erase::Erased<[u8; 8usize]>>
  34:     0x7f6d512ee4ec - rustc_query_system[6bf3121dceac80f2]::query::plumbing::try_execute_query::<rustc_query_impl[514e88206e175c88]::DynamicConfig<rustc_data_structures[af9d6d584b86a654]::vec_cache::VecCache<rustc_span[fb0caa589edbc834]::def_id::LocalDefId, rustc_middle[cbfbdec2b42921ad]::query::erase::Erased<[u8; 8usize]>, rustc_query_system[6bf3121dceac80f2]::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl[514e88206e175c88]::plumbing::QueryCtxt, false>
  35:     0x7f6d512ede8b - rustc_query_impl[514e88206e175c88]::query_impl::typeck::get_query_non_incr::__rust_end_short_backtrace
  36:     0x7f6d512ec9dc - rustc_hir_analysis[93d6ba5a7e3de542]::check_crate
  37:     0x7f6d518adddd - rustc_interface[ad1617c32d4bf039]::passes::run_required_analyses
  38:     0x7f6d5189c25e - rustc_interface[ad1617c32d4bf039]::passes::analysis
  39:     0x7f6d5189c22d - rustc_query_impl[514e88206e175c88]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[514e88206e175c88]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[cbfbdec2b42921ad]::query::erase::Erased<[u8; 0usize]>>
  40:     0x7f6d51fc177d - rustc_query_system[6bf3121dceac80f2]::query::plumbing::try_execute_query::<rustc_query_impl[514e88206e175c88]::DynamicConfig<rustc_query_system[6bf3121dceac80f2]::query::caches::SingleCache<rustc_middle[cbfbdec2b42921ad]::query::erase::Erased<[u8; 0usize]>>, false, false, false>, rustc_query_impl[514e88206e175c88]::plumbing::QueryCtxt, false>
  41:     0x7f6d51fc1478 - rustc_query_impl[514e88206e175c88]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  42:     0x7f6d522e474d - rustc_interface[ad1617c32d4bf039]::passes::create_and_enter_global_ctxt::<core[64194c3d1231b2c8]::option::Option<rustc_interface[ad1617c32d4bf039]::queries::Linker>, rustc_driver_impl[2a6f85d55f84b44d]::run_compiler::{closure#0}::{closure#2}>::{closure#2}::{closure#0}
  43:     0x7f6d521950ea - rustc_interface[ad1617c32d4bf039]::interface::run_compiler::<(), rustc_driver_impl[2a6f85d55f84b44d]::run_compiler::{closure#0}>::{closure#1}
  44:     0x7f6d521367d2 - std[43c66c29bb2da0cf]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[ad1617c32d4bf039]::util::run_in_thread_with_globals<rustc_interface[ad1617c32d4bf039]::util::run_in_thread_pool_with_globals<rustc_interface[ad1617c32d4bf039]::interface::run_compiler<(), rustc_driver_impl[2a6f85d55f84b44d]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
  45:     0x7f6d521370b4 - <<std[43c66c29bb2da0cf]::thread::Builder>::spawn_unchecked_<rustc_interface[ad1617c32d4bf039]::util::run_in_thread_with_globals<rustc_interface[ad1617c32d4bf039]::util::run_in_thread_pool_with_globals<rustc_interface[ad1617c32d4bf039]::interface::run_compiler<(), rustc_driver_impl[2a6f85d55f84b44d]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core[64194c3d1231b2c8]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  46:     0x7f6d521384ab - std::sys::pal::unix::thread::Thread::new::thread_start::hc13d05e8634371ab
  47:     0x7f6d4bea81f5 - start_thread
                               at ./nptl/pthread_create.c:442:8
  48:     0x7f6d4bf2889c - clone3
                               at ./misc/../sysdeps/unix/sysv/linux/x86_64/clone3.S:81:0
  49:                0x0 - <unknown>


rustc version: 1.88.0-nightly (e2014e876 2025-04-01)
platform: x86_64-unknown-linux-gnu

query stack during panic:
#0 [eval_to_allocation_raw] const-evaluating + checking `Arr::{constant#0}`
#1 [eval_to_valtree] evaluating type-level constant
#2 [typeck] type-checking `main`
#3 [analysis] running analysis passes on this crate
end of query stack

[matthiaskrgr]

I think this is a duplicate of #125772 except with - instead of *