ICE with mismatch in trait associated constant

[jruderman]

Code

#![feature(associated_const_equality)]
#![allow(dead_code)]

trait TraitWAssocConst {
    const A: usize;
}

fn foo<T: TraitWAssocConst<A = 1>>() {}

fn bar<T: TraitWAssocConst<A = 0>>() {
    foo::<T>();
}

fn main() {}

Error output

thread <unnamed> panicked at 'called Option::unwrap() on a None value', compiler/rustc_trait_selection/src/traits/project.rs:562

Backtrace

   0:        0x10ebef796 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hd6dea84f06cc919a
   1:        0x10ec4e15a - core::fmt::write::h91ecc43dcb5a87d3
   2:        0x10ebe1c5c - std::io::Write::write_fmt::hc922635edee92051
   3:        0x10ebef57a - std::sys_common::backtrace::print::h86bd5791976d67a9
   4:        0x10ebf28e3 - std::panicking::default_hook::{{closure}}::h32c4d35e1d887df2
   5:        0x10ebf2638 - std::panicking::default_hook::hcd90b2b89f8c0e15
   6:        0x10ebf30a3 - std::panicking::rust_panic_with_hook::h9198f3fe823c744c
   7:        0x10ebf2e33 - std::panicking::begin_panic_handler::{{closure}}::h935bfbd23a054b53
   8:        0x10ebefc38 - std::sys_common::backtrace::__rust_end_short_backtrace::h1a500d61b73a0659
   9:        0x10ebf2b3d - _rust_begin_unwind
  10:        0x10ec7a903 - core::panicking::panic_fmt::he9045b6279698c2c
  11:        0x10ec7a9d7 - core::panicking::panic::h8341ec280685e050
  12:        0x11a8be735 - <rustc_trait_selection[a1a4268d0f076ce6]::traits::project::AssocTypeNormalizer as rustc_middle[81f54e6dd5330834]::ty::fold::TypeFolder>::fold_ty
  13:        0x11a8bd618 - <rustc_trait_selection[a1a4268d0f076ce6]::traits::project::AssocTypeNormalizer>::fold::<rustc_middle[81f54e6dd5330834]::ty::Ty>
  14:        0x11a8c4bd7 - rustc_trait_selection[a1a4268d0f076ce6]::traits::project::normalize_with_depth_to::<rustc_middle[81f54e6dd5330834]::ty::Ty>
  15:        0x11a955d8f - <rustc_infer[4bee525d6ce90e13]::infer::at::At as rustc_trait_selection[a1a4268d0f076ce6]::traits::project::NormalizeExt>::normalize::<rustc_middle[81f54e6dd5330834]::ty::Ty>
  16:        0x11a9f3d4e - <rustc_trait_selection[a1a4268d0f076ce6]::traits::engine::ObligationCtxt>::normalize::<rustc_middle[81f54e6dd5330834]::ty::Ty>
  17:        0x11a9344f5 - <rustc_infer[4bee525d6ce90e13]::infer::InferCtxt>::probe::<(), <rustc_infer[4bee525d6ce90e13]::infer::error_reporting::TypeErrCtxt as rustc_trait_selection[a1a4268d0f076ce6]::traits::error_reporting::InferCtxtPrivExt>::report_projection_error::{closure#0}>
  18:        0x11a9deb24 - <rustc_infer[4bee525d6ce90e13]::infer::error_reporting::TypeErrCtxt as rustc_trait_selection[a1a4268d0f076ce6]::traits::error_reporting::InferCtxtPrivExt>::report_fulfillment_error
  19:        0x11a9cd0a3 - <rustc_infer[4bee525d6ce90e13]::infer::error_reporting::TypeErrCtxt as rustc_trait_selection[a1a4268d0f076ce6]::traits::error_reporting::TypeErrCtxtExt>::report_fulfillment_errors
  20:        0x11911a1ff - <rustc_hir_typeck[207f971536c734c5]::fn_ctxt::FnCtxt>::check_argument_types
  21:        0x1190f3bd4 - <rustc_hir_typeck[207f971536c734c5]::fn_ctxt::FnCtxt>::confirm_builtin_call
  22:        0x1190f0add - <rustc_hir_typeck[207f971536c734c5]::fn_ctxt::FnCtxt>::check_call
  23:        0x1191710cd - <rustc_hir_typeck[207f971536c734c5]::fn_ctxt::FnCtxt>::check_expr_kind
  24:        0x119107c8f - <rustc_hir_typeck[207f971536c734c5]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  25:        0x119122505 - <rustc_hir_typeck[207f971536c734c5]::fn_ctxt::FnCtxt>::check_stmt
  26:        0x119122c2f - <rustc_hir_typeck[207f971536c734c5]::fn_ctxt::FnCtxt>::check_block_with_expected
  27:        0x1191714af - <rustc_hir_typeck[207f971536c734c5]::fn_ctxt::FnCtxt>::check_expr_kind
  28:        0x119107c8f - <rustc_hir_typeck[207f971536c734c5]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  29:        0x119109850 - <rustc_hir_typeck[207f971536c734c5]::fn_ctxt::FnCtxt>::check_return_expr
  30:        0x1192adeed - rustc_hir_typeck[207f971536c734c5]::check::check_fn
  31:        0x119218f1a - <rustc_hir_typeck[207f971536c734c5]::inherited::InheritedBuilder>::enter::<rustc_hir_typeck[207f971536c734c5]::typeck_with_fallback<rustc_hir_typeck[207f971536c734c5]::typeck::{closure#0}>::{closure#0}::{closure#1}, &rustc_middle[81f54e6dd5330834]::ty::context::TypeckResults>
  32:        0x119241089 - rustc_hir_typeck[207f971536c734c5]::typeck
  33:        0x11a11fa39 - rustc_query_system[179a71b5a36883c6]::query::plumbing::try_execute_query::<rustc_query_impl[964bc029a4576ad4]::plumbing::QueryCtxt, rustc_query_system[179a71b5a36883c6]::query::caches::VecCache<rustc_span[e3bcd7e2de09f7c3]::def_id::LocalDefId, &rustc_middle[81f54e6dd5330834]::ty::context::TypeckResults>>
  34:        0x11a19f144 - rustc_query_system[179a71b5a36883c6]::query::plumbing::get_query::<rustc_query_impl[964bc029a4576ad4]::queries::typeck, rustc_query_impl[964bc029a4576ad4]::plumbing::QueryCtxt>
  35:        0x1192be777 - std[e9f68177e3155681]::panicking::try::<(), core[d953718cd3bcc963]::panic::unwind_safe::AssertUnwindSafe<rustc_data_structures[69a6efa400d2eccf]::sync::par_for_each_in<&[rustc_span[e3bcd7e2de09f7c3]::def_id::LocalDefId], <rustc_middle[81f54e6dd5330834]::hir::map::Map>::par_body_owners<rustc_hir_typeck[207f971536c734c5]::typeck_item_bodies::{closure#0}>::{closure#0}>::{closure#0}::{closure#0}>>
  36:        0x1192bcbf5 - rustc_data_structures[69a6efa400d2eccf]::sync::par_for_each_in::<&[rustc_span[e3bcd7e2de09f7c3]::def_id::LocalDefId], <rustc_middle[81f54e6dd5330834]::hir::map::Map>::par_body_owners<rustc_hir_typeck[207f971536c734c5]::typeck_item_bodies::{closure#0}>::{closure#0}>
  37:        0x119240737 - rustc_hir_typeck[207f971536c734c5]::typeck_item_bodies
  38:        0x11a0ed6b4 - rustc_query_system[179a71b5a36883c6]::query::plumbing::try_execute_query::<rustc_query_impl[964bc029a4576ad4]::plumbing::QueryCtxt, rustc_query_system[179a71b5a36883c6]::query::caches::DefaultCache<(), ()>>
  39:        0x11a1920b1 - rustc_query_system[179a71b5a36883c6]::query::plumbing::get_query::<rustc_query_impl[964bc029a4576ad4]::queries::typeck_item_bodies, rustc_query_impl[964bc029a4576ad4]::plumbing::QueryCtxt>
  40:        0x118f6e863 - <rustc_session[78db928f84e94300]::session::Session>::time::<(), rustc_hir_analysis[7e82910673f8c84]::check_crate::{closure#7}>
  41:        0x118fbb1a6 - rustc_hir_analysis[7e82910673f8c84]::check_crate
  42:        0x1194decb0 - rustc_interface[9fb4355f0ea261b0]::passes::analysis
  43:        0x11a0dc482 - rustc_query_system[179a71b5a36883c6]::query::plumbing::try_execute_query::<rustc_query_impl[964bc029a4576ad4]::plumbing::QueryCtxt, rustc_query_system[179a71b5a36883c6]::query::caches::DefaultCache<(), core[d953718cd3bcc963]::result::Result<(), rustc_errors[6e8b1009bf902fa9]::ErrorGuaranteed>>>
  44:        0x11a19f521 - rustc_query_system[179a71b5a36883c6]::query::plumbing::get_query::<rustc_query_impl[964bc029a4576ad4]::queries::analysis, rustc_query_impl[964bc029a4576ad4]::plumbing::QueryCtxt>
  45:        0x118c4160a - <rustc_interface[9fb4355f0ea261b0]::passes::QueryContext>::enter::<rustc_driver[f5ca9ba73eed523d]::run_compiler::{closure#1}::{closure#2}::{closure#2}, core[d953718cd3bcc963]::result::Result<(), rustc_errors[6e8b1009bf902fa9]::ErrorGuaranteed>>
  46:        0x118c899cb - rustc_span[e3bcd7e2de09f7c3]::with_source_map::<core[d953718cd3bcc963]::result::Result<(), rustc_errors[6e8b1009bf902fa9]::ErrorGuaranteed>, rustc_interface[9fb4355f0ea261b0]::interface::run_compiler<core[d953718cd3bcc963]::result::Result<(), rustc_errors[6e8b1009bf902fa9]::ErrorGuaranteed>, rustc_driver[f5ca9ba73eed523d]::run_compiler::{closure#1}>::{closure#0}::{closure#0}>
  47:        0x118c7b8ee - <scoped_tls[10e5aad72c190240]::ScopedKey<rustc_span[e3bcd7e2de09f7c3]::SessionGlobals>>::set::<rustc_interface[9fb4355f0ea261b0]::interface::run_compiler<core[d953718cd3bcc963]::result::Result<(), rustc_errors[6e8b1009bf902fa9]::ErrorGuaranteed>, rustc_driver[f5ca9ba73eed523d]::run_compiler::{closure#1}>::{closure#0}, core[d953718cd3bcc963]::result::Result<(), rustc_errors[6e8b1009bf902fa9]::ErrorGuaranteed>>
  48:        0x118c4a3b7 - std[e9f68177e3155681]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[9fb4355f0ea261b0]::util::run_in_thread_pool_with_globals<rustc_interface[9fb4355f0ea261b0]::interface::run_compiler<core[d953718cd3bcc963]::result::Result<(), rustc_errors[6e8b1009bf902fa9]::ErrorGuaranteed>, rustc_driver[f5ca9ba73eed523d]::run_compiler::{closure#1}>::{closure#0}, core[d953718cd3bcc963]::result::Result<(), rustc_errors[6e8b1009bf902fa9]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[d953718cd3bcc963]::result::Result<(), rustc_errors[6e8b1009bf902fa9]::ErrorGuaranteed>>
  49:        0x118c2cdb9 - <<std[e9f68177e3155681]::thread::Builder>::spawn_unchecked_<rustc_interface[9fb4355f0ea261b0]::util::run_in_thread_pool_with_globals<rustc_interface[9fb4355f0ea261b0]::interface::run_compiler<core[d953718cd3bcc963]::result::Result<(), rustc_errors[6e8b1009bf902fa9]::ErrorGuaranteed>, rustc_driver[f5ca9ba73eed523d]::run_compiler::{closure#1}>::{closure#0}, core[d953718cd3bcc963]::result::Result<(), rustc_errors[6e8b1009bf902fa9]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[d953718cd3bcc963]::result::Result<(), rustc_errors[6e8b1009bf902fa9]::ErrorGuaranteed>>::{closure#1} as core[d953718cd3bcc963]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  50:        0x11ac1f3a7 - std::sys::unix::thread::Thread::new::thread_start::h6bf891e61773eb8a
  51:     0x7ff80c3874e1 - __pthread_start

Regression

Regression in nightly-2022-12-04, in rollup 24f2704, likely from #104903 (@spastorino, @lcnr)

Version

rustc 1.68.0-nightly (bdb07a8ec 2022-12-11)
binary: rustc
commit-hash: bdb07a8ec8e77aa10fb84fae1d4ff71c21180bb4
commit-date: 2022-12-11
host: x86_64-apple-darwin
release: 1.68.0-nightly
LLVM version: 15.0.6