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matthiaskrgr opened this issue Feb 28, 2025 · 6 comments · Fixed by #140553 · May be fixed by #137972
Closed

ICE: did not expect inference variables here (wfck) #137813

matthiaskrgr opened this issue Feb 28, 2025 · 6 comments · Fixed by #140553 · May be fixed by #137972
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@BoxyUwU
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C-bug Category: This is a bug. F-associated_const_equality `#![feature(associated_const_equality)]` I-ICE Issue: The compiler panicked, giving an Internal Compilation Error (ICE) ❄️ S-bug-has-test Status: This bug is tracked inside the repo by a `known-bug` test. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue.

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@matthiaskrgr
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auto-reduced (treereduce-rust):

//@compile-flags: -Zincremental-verify-ich=yes -Cincremental=<dir> -Cdebuginfo=2 -Clink-dead-code=true -Zvalidate-mir --edition=2024
pub struct NoPin;

pub trait PinA<PER> {
    const A: u8;
}

impl<PER> PinA<PER> for NoPin {
    const A: u8 = 0;
}

pub trait Pins<USART> {}

impl<USART, T> Pins for T where T: PinA<USART, A = { TA }> {}

impl<USART> Serial<USART> where NoPin: Pins<USART> {}
original code

original:

// ICE assertion failed: matches!(self.def_kind(ct.def.did), DefKind :: AnonConst)
// issue: rust-lang/rust#108220
//@ check-pass

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

use std::marker::PhantomData;

pub struct NoPin;

pub trait SetAlternate<const A: u8> {}

impl SetAlternate<0> for NoPin {}

pub trait PinA<PER> {
    const A: u8;
}

impl<PER> PinA<PER> for NoPin {
    const A: u8 = 0;
}

pub trait Pins<USART> {}

impl<USART, T, const TA: u8> Pins<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S
<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<S<Z>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> for T where
    T: PinA<USART, A = { TA }> + SetAlternate<TA>
{
}

struct Serial<USART>(PhantomData<USART>);

impl<USART> Serial<USART> where NoPin: Pins<USART> {}

fn main() {}

Version information

rustc 1.87.0-nightly (2f581937e 2025-02-28)
binary: rustc
commit-hash: 2f581937e1c06adb4607df1b571c0bef6d98e6ec
commit-date: 2025-02-28
host: x86_64-unknown-linux-gnu
release: 1.87.0-nightly
LLVM version: 20.1.0

Possibly related line of code:

rust/compiler/rustc_middle/src/mir/interpret/queries.rs

Lines 99 to 111 in 2f58193

// variables. We reject those here since `resolve`
// would fail otherwise.
//
// When trying to evaluate constants containing inference variables,
// use `Infcx::const_eval_resolve` instead.
if ct.args.has_non_region_infer() {
bug!("did not expect inference variables here");
}
match ty::Instance::try_resolve(self, typing_env, ct.def, ct.args) {
Ok(Some(instance)) => {
let cid = GlobalId { instance, promoted: None };
self.const_eval_global_id_for_typeck(typing_env, cid, span).inspect(|_| {

Command:
/home/matthias/.rustup/toolchains/master/bin/rustc -Zincremental-verify-ich=yes -Cincremental=<dir> -Cdebuginfo=2 -Clink-dead-code=true -Zvalidate-mir --edition=2024

Program output 

error[E0425]: cannot find value `TA` in this scope
  --> /tmp/icemaker_global_tempdir.tBkXQn2yGgp5/rustc_testrunner_tmpdir_reporting.jQl3AZtGBbLi/mvce.rs:13:54
   |
13 | impl<USART, T> Pins for T where T: PinA<USART, A = { TA }> {}
   |                                                      ^^ not found in this scope

error[E0412]: cannot find type `Serial` in this scope
  --> /tmp/icemaker_global_tempdir.tBkXQn2yGgp5/rustc_testrunner_tmpdir_reporting.jQl3AZtGBbLi/mvce.rs:15:13
   |
15 | impl<USART> Serial<USART> where NoPin: Pins<USART> {}
   |             ^^^^^^ not found in this scope

error[E0658]: associated const equality is incomplete
  --> /tmp/icemaker_global_tempdir.tBkXQn2yGgp5/rustc_testrunner_tmpdir_reporting.jQl3AZtGBbLi/mvce.rs:13:48
   |
13 | impl<USART, T> Pins for T where T: PinA<USART, A = { TA }> {}
   |                                                ^^^^^^^^^^
   |
   = note: see issue #92827 <https://github.com/rust-lang/rust/issues/92827> for more information
   = help: add `#![feature(associated_const_equality)]` to the crate attributes to enable
   = note: this compiler was built on 2025-02-28; consider upgrading it if it is out of date

error[E0601]: `main` function not found in crate `mvce`
  --> /tmp/icemaker_global_tempdir.tBkXQn2yGgp5/rustc_testrunner_tmpdir_reporting.jQl3AZtGBbLi/mvce.rs:15:54
   |
15 | impl<USART> Serial<USART> where NoPin: Pins<USART> {}
   |                                                      ^ consider adding a `main` function to `/tmp/icemaker_global_tempdir.tBkXQn2yGgp5/rustc_testrunner_tmpdir_reporting.jQl3AZtGBbLi/mvce.rs`

error[E0107]: missing generics for trait `Pins`
  --> /tmp/icemaker_global_tempdir.tBkXQn2yGgp5/rustc_testrunner_tmpdir_reporting.jQl3AZtGBbLi/mvce.rs:13:16
   |
13 | impl<USART, T> Pins for T where T: PinA<USART, A = { TA }> {}
   |                ^^^^ expected 1 generic argument
   |
note: trait defined here, with 1 generic parameter: `USART`
  --> /tmp/icemaker_global_tempdir.tBkXQn2yGgp5/rustc_testrunner_tmpdir_reporting.jQl3AZtGBbLi/mvce.rs:11:11
   |
11 | pub trait Pins<USART> {}
   |           ^^^^ -----
help: add missing generic argument
   |
13 | impl<USART, T> Pins<USART> for T where T: PinA<USART, A = { TA }> {}
   |                    +++++++

error: internal compiler error: compiler/rustc_middle/src/mir/interpret/queries.rs:105:13: did not expect inference variables here


thread 'rustc' panicked at compiler/rustc_middle/src/mir/interpret/queries.rs:105:13:
Box<dyn Any>
stack backtrace:
   0:     0x726a695b8794 - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::h8271bd9d6917c499
   1:     0x726a69e166ec - core::fmt::write::hc10118529572c35a
   2:     0x726a6af0a4d1 - std::io::Write::write_fmt::hd4cd3c690e338654
   3:     0x726a695b85f2 - std::sys::backtrace::BacktraceLock::print::hdbbabde34d7ae3a2
   4:     0x726a695bae2e - std::panicking::default_hook::{{closure}}::ha43c2eef4240d1ec
   5:     0x726a695baa04 - std::panicking::default_hook::h40675286f8693d93
   6:     0x726a687168c7 - std[671130e388b9fe6c]::panicking::update_hook::<alloc[bf8eb75a1b7fb173]::boxed::Box<rustc_driver_impl[91dbdd509552bee2]::install_ice_hook::{closure#1}>>::{closure#0}
   7:     0x726a695bb6a3 - std::panicking::rust_panic_with_hook::h89d32dff83379cbd
   8:     0x726a68753571 - std[671130e388b9fe6c]::panicking::begin_panic::<rustc_errors[498bbaf2ad3cdb45]::ExplicitBug>::{closure#0}
   9:     0x726a68747986 - std[671130e388b9fe6c]::sys::backtrace::__rust_end_short_backtrace::<std[671130e388b9fe6c]::panicking::begin_panic<rustc_errors[498bbaf2ad3cdb45]::ExplicitBug>::{closure#0}, !>
  10:     0x726a68744309 - std[671130e388b9fe6c]::panicking::begin_panic::<rustc_errors[498bbaf2ad3cdb45]::ExplicitBug>
  11:     0x726a6875cf61 - <rustc_errors[498bbaf2ad3cdb45]::diagnostic::BugAbort as rustc_errors[498bbaf2ad3cdb45]::diagnostic::EmissionGuarantee>::emit_producing_guarantee
  12:     0x726a68d312f6 - rustc_middle[5ec6377ace10fe5f]::util::bug::opt_span_bug_fmt::<rustc_span[f0d5d7aa1c3a11e8]::span_encoding::Span>::{closure#0}
  13:     0x726a68d18c0a - rustc_middle[5ec6377ace10fe5f]::ty::context::tls::with_opt::<rustc_middle[5ec6377ace10fe5f]::util::bug::opt_span_bug_fmt<rustc_span[f0d5d7aa1c3a11e8]::span_encoding::Span>::{closure#0}, !>::{closure#0}
  14:     0x726a68d18a7b - rustc_middle[5ec6377ace10fe5f]::ty::context::tls::with_context_opt::<rustc_middle[5ec6377ace10fe5f]::ty::context::tls::with_opt<rustc_middle[5ec6377ace10fe5f]::util::bug::opt_span_bug_fmt<rustc_span[f0d5d7aa1c3a11e8]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
  15:     0x726a6729b9a0 - rustc_middle[5ec6377ace10fe5f]::util::bug::bug_fmt
  16:     0x726a6b76eed0 - <rustc_middle[5ec6377ace10fe5f]::ty::context::TyCtxt>::const_eval_resolve_for_typeck.cold
  17:     0x726a6a66f9e5 - rustc_trait_selection[f5f12f31b8a38df8]::traits::try_evaluate_const
  18:     0x726a6a66f5c3 - <rustc_trait_selection[f5f12f31b8a38df8]::traits::normalize::AssocTypeNormalizer as rustc_type_ir[a5adda4a46b2bae1]::fold::TypeFolder<rustc_middle[5ec6377ace10fe5f]::ty::context::TyCtxt>>::fold_const
  19:     0x726a6a1fe71f - rustc_trait_selection[f5f12f31b8a38df8]::traits::project::opt_normalize_projection_term
  20:     0x726a69f64281 - rustc_trait_selection[f5f12f31b8a38df8]::traits::project::poly_project_and_unify_term
  21:     0x726a69f6a151 - <rustc_trait_selection[f5f12f31b8a38df8]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}
  22:     0x726a6ae1e526 - <rustc_trait_selection[f5f12f31b8a38df8]::traits::select::SelectionContext>::candidate_from_obligation::{closure#0}::{closure#0}
  23:     0x726a69fc3ddd - <rustc_trait_selection[f5f12f31b8a38df8]::traits::select::SelectionContext>::poly_select::{closure#0}
  24:     0x726a6a6df86f - <rustc_trait_selection[f5f12f31b8a38df8]::traits::fulfill::FulfillProcessor as rustc_data_structures[24cbe30c54d054aa]::obligation_forest::ObligationProcessor>::process_obligation
  25:     0x726a69e0e1e9 - <rustc_data_structures[24cbe30c54d054aa]::obligation_forest::ObligationForest<rustc_trait_selection[f5f12f31b8a38df8]::traits::fulfill::PendingPredicateObligation>>::process_obligations::<rustc_trait_selection[f5f12f31b8a38df8]::traits::fulfill::FulfillProcessor>
  26:     0x726a6a2c4607 - <rustc_trait_selection[f5f12f31b8a38df8]::traits::fulfill::FulfillmentContext<rustc_trait_selection[f5f12f31b8a38df8]::traits::FulfillmentError> as rustc_infer[6424dac916e4534e]::traits::engine::TraitEngine<rustc_trait_selection[f5f12f31b8a38df8]::traits::FulfillmentError>>::select_all_or_error
  27:     0x726a6a570a47 - rustc_hir_analysis[5ff3dce2dca2fb41]::check::wfcheck::check_well_formed
  28:     0x726a6a56f391 - rustc_query_impl[ee3276488b06594c]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[ee3276488b06594c]::query_impl::check_well_formed::dynamic_query::{closure#2}::{closure#0}, rustc_middle[5ec6377ace10fe5f]::query::erase::Erased<[u8; 1usize]>>
  29:     0x726a6a32e1a1 - rustc_query_system[c27e8fb22d1ec87f]::query::plumbing::try_execute_query::<rustc_query_impl[ee3276488b06594c]::DynamicConfig<rustc_data_structures[24cbe30c54d054aa]::vec_cache::VecCache<rustc_span[f0d5d7aa1c3a11e8]::def_id::LocalDefId, rustc_middle[5ec6377ace10fe5f]::query::erase::Erased<[u8; 1usize]>, rustc_query_system[c27e8fb22d1ec87f]::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl[ee3276488b06594c]::plumbing::QueryCtxt, true>
  30:     0x726a6a33292c - rustc_query_impl[ee3276488b06594c]::query_impl::check_well_formed::get_query_incr::__rust_end_short_backtrace
  31:     0x726a6a56c11d - rustc_hir_analysis[5ff3dce2dca2fb41]::check::wfcheck::check_mod_type_wf
  32:     0x726a6a56bf1f - rustc_query_impl[ee3276488b06594c]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[ee3276488b06594c]::query_impl::check_mod_type_wf::dynamic_query::{closure#2}::{closure#0}, rustc_middle[5ec6377ace10fe5f]::query::erase::Erased<[u8; 1usize]>>
  33:     0x726a6add7120 - rustc_query_system[c27e8fb22d1ec87f]::query::plumbing::try_execute_query::<rustc_query_impl[ee3276488b06594c]::DynamicConfig<rustc_query_system[c27e8fb22d1ec87f]::query::caches::DefaultCache<rustc_span[f0d5d7aa1c3a11e8]::def_id::LocalModDefId, rustc_middle[5ec6377ace10fe5f]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[ee3276488b06594c]::plumbing::QueryCtxt, true>
  34:     0x726a6add7b7b - rustc_query_impl[ee3276488b06594c]::query_impl::check_mod_type_wf::get_query_incr::__rust_end_short_backtrace
  35:     0x726a6a42258d - rustc_hir_analysis[5ff3dce2dca2fb41]::check_crate
  36:     0x726a6a41cb1c - rustc_interface[d2de745071f2696f]::passes::run_required_analyses
  37:     0x726a6ae87cfa - rustc_interface[d2de745071f2696f]::passes::analysis
  38:     0x726a6ae87cd9 - rustc_query_impl[ee3276488b06594c]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[ee3276488b06594c]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[5ec6377ace10fe5f]::query::erase::Erased<[u8; 0usize]>>
  39:     0x726a6ae835aa - rustc_query_system[c27e8fb22d1ec87f]::query::plumbing::try_execute_query::<rustc_query_impl[ee3276488b06594c]::DynamicConfig<rustc_query_system[c27e8fb22d1ec87f]::query::caches::SingleCache<rustc_middle[5ec6377ace10fe5f]::query::erase::Erased<[u8; 0usize]>>, false, false, false>, rustc_query_impl[ee3276488b06594c]::plumbing::QueryCtxt, true>
  40:     0x726a6ae82fa2 - rustc_query_impl[ee3276488b06594c]::query_impl::analysis::get_query_incr::__rust_end_short_backtrace
  41:     0x726a6af3fd7c - rustc_interface[d2de745071f2696f]::passes::create_and_enter_global_ctxt::<core[c921f6c857728d82]::option::Option<rustc_interface[d2de745071f2696f]::queries::Linker>, rustc_driver_impl[91dbdd509552bee2]::run_compiler::{closure#0}::{closure#2}>::{closure#2}::{closure#0}
  42:     0x726a6aef6fa0 - rustc_interface[d2de745071f2696f]::interface::run_compiler::<(), rustc_driver_impl[91dbdd509552bee2]::run_compiler::{closure#0}>::{closure#1}
  43:     0x726a6ada9788 - std[671130e388b9fe6c]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[d2de745071f2696f]::util::run_in_thread_with_globals<rustc_interface[d2de745071f2696f]::util::run_in_thread_pool_with_globals<rustc_interface[d2de745071f2696f]::interface::run_compiler<(), rustc_driver_impl[91dbdd509552bee2]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
  44:     0x726a6adaa074 - <<std[671130e388b9fe6c]::thread::Builder>::spawn_unchecked_<rustc_interface[d2de745071f2696f]::util::run_in_thread_with_globals<rustc_interface[d2de745071f2696f]::util::run_in_thread_pool_with_globals<rustc_interface[d2de745071f2696f]::interface::run_compiler<(), rustc_driver_impl[91dbdd509552bee2]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core[c921f6c857728d82]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  45:     0x726a6adab477 - std::sys::pal::unix::thread::Thread::new::thread_start::h3507b515c9e14c35
  46:     0x726a64ea370a - <unknown>
  47:     0x726a64f27aac - <unknown>
  48:                0x0 - <unknown>

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 1.87.0-nightly (2f581937e 2025-02-28) running on x86_64-unknown-linux-gnu

note: compiler flags: -Z incremental-verify-ich=yes -C incremental=[REDACTED] -C debuginfo=2 -C link-dead-code=true -Z validate-mir

query stack during panic:
#0 [check_well_formed] checking that `<impl at /tmp/icemaker_global_tempdir.tBkXQn2yGgp5/rustc_testrunner_tmpdir_reporting.jQl3AZtGBbLi/mvce.rs:15:1: 15:51>` is well-formed
#1 [check_mod_type_wf] checking that types are well-formed in top-level module
#2 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to 6 previous errors

Some errors have detailed explanations: E0107, E0412, E0425, E0601, E0658.
For more information about an error, try `rustc --explain E0107`.

@matthiaskrgr matthiaskrgr added C-bug Category: This is a bug. I-ICE Issue: The compiler panicked, giving an Internal Compilation Error (ICE) ❄️ T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels Feb 28, 2025
@rustbot rustbot added the needs-triage This issue may need triage. Remove it if it has been sufficiently triaged. label Feb 28, 2025
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seems to bisect to #132090

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smaller

struct A;
trait B<C> {
    const D: u8;
}
impl<C> B<C> for A {
    const D: u8 = 1;
}
trait E<F> {}
impl<F, G> E for G where G: B<F, D = {}> {}
impl<F> H where A: E<F> {}

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compiler-errors commented Feb 28, 2025 •
edited
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A bit more conceptually simpler:

trait AssocConst {
    const A: u8;
}

impl<T> AssocConst for (T,) {
    const A: u8 = 0;
}

trait Trait {}

impl<U> Trait for () where (U,): AssocConst<A = { 0 }> {}

fn foo()
where
    (): Trait,
{
}

@compiler-errors compiler-errors self-assigned this Feb 28, 2025
@fmease fmease added the F-associated_const_equality `#![feature(associated_const_equality)]` label Feb 28, 2025
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@Noratrieb Noratrieb removed the needs-triage This issue may need triage. Remove it if it has been sufficiently triaged. label Mar 1, 2025
@matthiaskrgr matthiaskrgr added the S-bug-has-test Status: This bug is tracked inside the repo by a `known-bug` test. label Mar 9, 2025
@BoxyUwU BoxyUwU assigned BoxyUwU and unassigned compiler-errors Apr 14, 2025
@BoxyUwU BoxyUwU mentioned this issue Apr 14, 2025
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@BoxyUwU BoxyUwU mentioned this issue May 1, 2025
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gendx commented May 13, 2025

Another example that triggers this bug:

#![feature(associated_const_equality)]

pub trait NeedsDrop {
    const NEEDS_DROP: bool;
}

impl<T> NeedsDrop for T {
    const NEEDS_DROP: bool = std::mem::needs_drop::<T>();
}

pub trait Foo {}

impl<T> Foo for T where T: NeedsDrop<NEEDS_DROP = false> {}

fn foo(x: impl Foo) {}

fn bar() {
    foo(32);
}

@bors bors closed this as completed in 52bf0cf May 23, 2025
compiler-errors pushed a commit to compiler-errors/rust that referenced this issue May 23, 2025
@bors @compiler-errors
Auto merge of rust-lang#140553 - BoxyUwU:defer_type_system_ctfe, r=co…
951526f 
…mpiler-errors

Defer evaluating type system constants when they use infers or params

Split out of rust-lang#137972, the parts necessary for associated const equality and min generic const args to make progress and have correct semantics around when CTFE is invoked. According to a [previous perf run](https://perf.rust-lang.org/compare.html?start=93257e2d20809d82d1bc0fcc1942480d1a66d7cd&end=01b4cbf0f47c3f782330db88fa5ba199bba1f8a2&stat=instructions:u) of adding the new `const_arg_kind` query we should expect minor regressions here.

I think this is acceptable as we should be able to remove this query relatively soon once mgca is more complete as we'll then be able to implement GCE in terms of mgca and rip out `GCEConst` at which point it's trivial to determine what kind of anon const we're dealing with (either it has generics and is a repeat expr hack, or it doesnt and is a normal anon const).

This should only affect unstable code as we handle repeat exprs specially and those are the only kinds of type system consts that are allowed to make use of generic parameters.

Fixes rust-lang#133066
Fixes rust-lang#133199
Fixes rust-lang#136894
Fixes rust-lang#137813

r? compiler-errors
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C-bug Category: This is a bug. F-associated_const_equality `#![feature(associated_const_equality)]` I-ICE Issue: The compiler panicked, giving an Internal Compilation Error (ICE) ❄️ S-bug-has-test Status: This bug is tracked inside the repo by a `known-bug` test. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue.
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