inline_const_pat ICE: broken MIR unexpected comparison types fn() {uwu} and fn() {uwu}

[asquared31415]

Code

#![allow(incomplete_features, dead_code)]
#![feature(inline_const_pat)]

fn uwu() {}

fn owo() {
    let x = [];
    // note: this `if false` is necessary, otherwise the ICE is different
    if false {
        // uncomment this for the code to compile
        // (and it even lets you use some unsafe tricks to get the function item)
        // x[99] = loop {};
        match x[123] {
            const { uwu } => {},
            _ => {}
        }
    }
}

playground

Meta

rustc --version --verbose:

rustc 1.73.0-nightly (03a119b0b 2023-08-07)
binary: rustc
commit-hash: 03a119b0b0e310d22d94399b24ed030056050f13
commit-date: 2023-08-07
host: x86_64-unknown-linux-gnu
release: 1.73.0-nightly
LLVM version: 16.0.5

Error output

error: internal compiler error: no errors encountered even though `delay_span_bug` issued

error: internal compiler error: broken MIR in DefId(0:4 ~ playground[b5a3]::owo) (Eq(<ZST>: fn() {uwu}, _1[_3])): unexpected comparison types fn() {uwu} and fn() {uwu}

Backtrace

error: internal compiler error: no errors encountered even though `delay_span_bug` issued

error: internal compiler error: broken MIR in DefId(0:4 ~ playground[b5a3]::owo) (Eq(<ZST>: fn() {uwu}, _1[_3])): unexpected comparison types fn() {uwu} and fn() {uwu}
  --> src/lib.rs:14:13
   |
14 |             const { uwu } => {},
   |             ^^^^^^^^^^^^^
   |
note: delayed at compiler/rustc_borrowck/src/type_check/mod.rs:2318:26
         0: <rustc_errors::HandlerInner>::emit_diagnostic
         1: <rustc_errors::Handler>::delay_span_bug::<rustc_span::span_encoding::Span, alloc::string::String>
         2: <rustc_borrowck::type_check::TypeChecker>::typeck_mir
         3: rustc_borrowck::type_check::type_check
         4: rustc_borrowck::nll::compute_regions
         5: rustc_borrowck::do_mir_borrowck
         6: rustc_borrowck::mir_borrowck
         7: rustc_query_impl::plumbing::__rust_begin_short_backtrace::<rustc_query_impl::query_impl::mir_borrowck::dynamic_query::{closure#2}::{closure#0}, rustc_middle::query::erase::Erased<[u8; 8]>>
         8: <rustc_query_impl::query_impl::mir_borrowck::dynamic_query::{closure#2} as core::ops::function::FnOnce<(rustc_middle::ty::context::TyCtxt, rustc_span::def_id::LocalDefId)>>::call_once
         9: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 8]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false>
        10: rustc_query_impl::query_impl::mir_borrowck::get_query_non_incr::__rust_end_short_backtrace
        11: rustc_data_structures::sync::par_for_each_in::<&[rustc_span::def_id::LocalDefId], <rustc_middle::hir::map::Map>::par_body_owners<rustc_interface::passes::analysis::{closure#1}::{closure#0}>::{closure#0}>
        12: <rustc_session::session::Session>::time::<(), rustc_interface::passes::analysis::{closure#1}>
        13: rustc_interface::passes::analysis
        14: rustc_query_impl::plumbing::__rust_begin_short_backtrace::<rustc_query_impl::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle::query::erase::Erased<[u8; 1]>>
        15: <rustc_query_impl::query_impl::analysis::dynamic_query::{closure#2} as core::ops::function::FnOnce<(rustc_middle::ty::context::TyCtxt, ())>>::call_once
        16: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::SingleCache<rustc_middle::query::erase::Erased<[u8; 1]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false>
        17: rustc_query_impl::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
        18: <rustc_middle::ty::context::GlobalCtxt>::enter::<rustc_driver_impl::run_compiler::{closure#1}::{closure#2}::{closure#6}, core::result::Result<(), rustc_span::ErrorGuaranteed>>
        19: rustc_span::set_source_map::<core::result::Result<(), rustc_span::ErrorGuaranteed>, rustc_interface::interface::run_compiler<core::result::Result<(), rustc_span::ErrorGuaranteed>, rustc_driver_impl::run_compiler::{closure#1}>::{closure#0}::{closure#0}>
        20: std::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<core::result::Result<(), rustc_span::ErrorGuaranteed>, rustc_driver_impl::run_compiler::{closure#1}>::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#0}::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>
        21: <<std::thread::Builder>::spawn_unchecked_<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<core::result::Result<(), rustc_span::ErrorGuaranteed>, rustc_driver_impl::run_compiler::{closure#1}>::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#0}::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#1} as core::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
        22: <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once
                   at /rustc/f88a8b71cebb730cbd5058c45ebcae1d4d9be377/library/alloc/src/boxed.rs:2007:9
        23: <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once
                   at /rustc/f88a8b71cebb730cbd5058c45ebcae1d4d9be377/library/alloc/src/boxed.rs:2007:9
        24: std::sys::unix::thread::Thread::new::thread_start
                   at /rustc/f88a8b71cebb730cbd5058c45ebcae1d4d9be377/library/std/src/sys/unix/thread.rs:108:17
        25: start_thread
        26: clone
  --> src/lib.rs:14:13
   |
14 |             const { uwu } => {},
   |             ^^^^^^^^^^^^^

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 attach the file at `/playground/rustc-ice-2023-08-09T15:58:06.807784224Z-18.txt` to your bug report

note: compiler flags: --crate-type lib -C embed-bitcode=no -C codegen-units=1 -C debuginfo=2

note: some of the compiler flags provided by cargo are hidden

query stack during panic:
end of query stack

@rustbot label +requires-nightly +F-inline_const_pat +requires-incomplete-features