ice: `const_trait_impl`: `async` functions cannot be `const fn`

[matthiaskrgr]

Code

rustc --edition=2021

#![feature(const_trait_impl)]

#[const_trait]
trait Tr {
    async fn ft1() {}
}

fn main() {}

Meta

rustc --version --verbose:

rustc 1.75.0-nightly (c1ccc29cd 2023-11-05)
binary: rustc
commit-hash: c1ccc29cd6eeb79f24511d75e9db553385a5d73f
commit-date: 2023-11-05
host: x86_64-unknown-linux-gnu
release: 1.75.0-nightly
LLVM version: 17.0.4

Error output

<output>

Backtrace

``` error: internal compiler error: no errors encountered even though `delay_span_bug` issued error: internal compiler error: `async` functions cannot be `const fn` --> crash.rs:5:5 | 5 | async fn ft1() {} | ^^^^^^^^^^^^^^^^^ | note: delayed at compiler/rustc_const_eval/src/transform/check_consts/check.rs:251:22 0: ::emit_diagnostic 1: ::delay_span_bug:: 2: rustc_mir_transform::mir_const_qualif 3: rustc_query_impl::plumbing::__rust_begin_short_backtrace::> 4: rustc_query_system::query::plumbing::try_execute_query::>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false> 5: rustc_query_impl::query_impl::mir_const_qualif::get_query_non_incr::__rust_end_short_backtrace 6: rustc_mir_transform::mir_promoted 7: rustc_query_impl::plumbing::__rust_begin_short_backtrace::> 8: rustc_query_system::query::plumbing::try_execute_query::>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false> 9: rustc_query_impl::query_impl::mir_promoted::get_query_non_incr::__rust_end_short_backtrace 10: rustc_borrowck::mir_borrowck 11: rustc_query_impl::plumbing::__rust_begin_short_backtrace::> 12: rustc_query_system::query::plumbing::try_execute_query::>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false> 13: rustc_query_impl::query_impl::mir_borrowck::get_query_non_incr::__rust_end_short_backtrace 14: rustc_hir_analysis::collect::type_of::type_of_opaque 15: rustc_query_impl::plumbing::__rust_begin_short_backtrace::> 16: rustc_query_system::query::plumbing::try_execute_query::>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false> 17: rustc_query_impl::query_impl::type_of_opaque::get_query_non_incr::__rust_end_short_backtrace 18: rustc_middle::query::plumbing::query_get_at::>> 19: rustc_hir_analysis::collect::type_of::type_of 20: rustc_query_impl::plumbing::__rust_begin_short_backtrace::> 21: rustc_query_system::query::plumbing::try_execute_query::>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false> 22: rustc_query_impl::query_impl::type_of::get_query_non_incr::__rust_end_short_backtrace 23: rustc_middle::query::plumbing::query_get_at::>> 24: rustc_hir_analysis::check::check::check_mod_item_types 25: rustc_query_impl::plumbing::__rust_begin_short_backtrace::> 26: rustc_query_system::query::plumbing::try_execute_query::>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false> 27: rustc_query_impl::query_impl::check_mod_item_types::get_query_non_incr::__rust_end_short_backtrace 28: rustc_hir_analysis::check_crate 29: rustc_interface::passes::analysis 30: rustc_query_impl::plumbing::__rust_begin_short_backtrace::> 31: rustc_query_system::query::plumbing::try_execute_query::>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false> 32: rustc_query_impl::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace 33: rustc_interface::interface::run_compiler::, rustc_driver_impl::run_compiler::{closure#1}>::{closure#0} 34: std::sys_common::backtrace::__rust_begin_short_backtrace::, 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>> 35: <::spawn_unchecked_, 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} 36: as core::ops::function::FnOnce>::call_once at /rustc/c1ccc29cd6eeb79f24511d75e9db553385a5d73f/library/alloc/src/boxed.rs:2007:9 37: as core::ops::function::FnOnce>::call_once at /rustc/c1ccc29cd6eeb79f24511d75e9db553385a5d73f/library/alloc/src/boxed.rs:2007:9 38: std::sys::unix::thread::Thread::new::thread_start at /rustc/c1ccc29cd6eeb79f24511d75e9db553385a5d73f/library/std/src/sys/unix/thread.rs:108:17 39: 40: --> crash.rs:5:5 | 5 | async fn ft1() {} | ^^^^^^^^^^^^^^^^^ 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 `/tmp/icemaker/rustc-ice-2023-11-06T10_23_53-2751136.txt` to your bug report query stack during panic: end of query stack error: aborting due to 2 previous errors ```

[matthiaskrgr]

nightly-2023-10-15 Regression in 481d45abeced571b533016a994cba7337102a4a4

if I add async_fn_in_trait, this bisects to

Regression in nightly-2023-03-15

commit[0] 2023-03-13: Auto merge of #109094 - Nilstrieb:no-thin-lto-on-windows, r=jyn514 commit[1] 2023-03-14: Auto merge of #109097 - matthiaskrgr:rollup-6ydc4ri, r=matthiaskrgr commit[2] 2023-03-14: Auto merge of #108992 - petrochenkov:qcstore2, r=cjgillot commit[3] 2023-03-14: Auto merge of #109057 - compiler-errors:rpitit-info-again, r=spastorino commit[4] 2023-03-14: Auto merge of #104833 - Swatinem:async-identity-future, r=compiler-errors commit[5] 2023-03-14: Auto merge of #106505 - Nilstrieb:format-args-string-literal-episode-2, r=petrochenkov commit[6] 2023-03-14: Auto merge of #109130 - matthiaskrgr:rollup-dm3jza6, r=matthiaskrgr