nightly ICE with unboxed async fn recursion

[spookyvision]

Code

trait Blah {
    async fn iter<T>(&mut self, iterator: T)
    where
        T: IntoIterator<Item = ()>;
}

impl Blah for () {
    async fn iter<T>(&mut self, iterator: T)
    where
        T: IntoIterator<Item = ()>,
    {
        Blah::iter(self, iterator).await
    }
}

struct Wrap<T: Blah> {
    t: T,
}

impl<T: Blah> Wrap<T>
where
    T: Blah,
{
    async fn ice(&mut self) {
        let arr: [(); 0] = [];
        self.t.iter(arr.into_iter()).await;
    }
}

#[tokio::main]
async fn main() {
    let mut t = Wrap { t: () };

    t.ice();
}

Meta

rustc --version --verbose:

rustc 1.83.0-nightly (3ae715c8c 2024-10-07)
binary: rustc
commit-hash: 3ae715c8c63f9aeac47cbf7d8d9dadb3fa32c638
commit-date: 2024-10-07
host: aarch64-apple-darwin
release: 1.83.0-nightly
LLVM version: 19.1.1

Error output

warning: unused implementer of `Future` that must be used
  --> src/main.rs:37:5
   |
37 |     t.ice();
   |     ^^^^^^^
   |
   = note: futures do nothing unless you `.await` or poll them
   = note: `#[warn(unused_must_use)]` on by default

error[E0733]: recursion in an async fn requires boxing
  --> src/main.rs:10:5
   |
10 | /     async fn write<T>(&mut self, iterator: T)
11 | |     where
12 | |         T: IntoIterator<Item = ()>,
   | |___________________________________^
13 |       {
14 |           Blah::write(self, iterator).await
   |           --------------------------------- recursive call here
   |
   = note: a recursive `async fn` call must introduce indirection such as `Box::pin` to avoid an infinitely sized future

error: internal compiler error: compiler/rustc_codegen_llvm/src/context.rs:1186:21: `fn_abi_of_instance(Wrap::<()>::ice, [])` failed: Layout(Cycle(ErrorGuaranteed(())))
  --> src/main.rs:26:5
   |
26 |     async fn ice(&mut self) {
   |     ^^^^^^^^^^^^^^^^^^^^^^^

thread 'rustc' panicked at compiler/rustc_codegen_llvm/src/context.rs:1186:21:
Box<dyn Any>
stack backtrace:

(pasted below, as per the template's instructions)

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: please attach the file at `/private/tmp/aec.24_07_03_17_29_39.wO/ice/rustc-ice-2024-10-08T16_47_37-3270.txt` to your bug report

note: compiler flags: --crate-type bin -C opt-level=3 -C embed-bitcode=no -C debuginfo=2 -C split-debuginfo=unpacked

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

query stack during panic:
end of query stack
For more information about this error, try `rustc --explain E0733`.
warning: `ice` (bin "ice") generated 1 warning
error: could not compile `ice` (bin "ice") due to 1 previous error; 1 warning emitted

Backtrace

   0:        0x10e54bd44 - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::ha1175e5d631924b6
   1:        0x10b8cd7dc - core::fmt::write::hb0b7e313ed56bf22
   2:        0x10e53fdf4 - std::io::Write::write_fmt::hd7b821ad1b2e3439
   3:        0x10e54bc04 - std::sys::backtrace::BacktraceLock::print::h3a7a2e7d356908ce
   4:        0x10e54e0d0 - std::panicking::default_hook::{{closure}}::h10557e6d4768ff4b
   5:        0x10e54df1c - std::panicking::default_hook::h4543f5bf1aacb61d
   6:        0x10c4d1fb4 - <alloc[33d0a6a508eb5932]::boxed::Box<rustc_driver_impl[c0574d6a9003aa16]::install_ice_hook::{closure#0}> as core[ef7e3446cee7ff23]::ops::function::Fn<(&dyn for<'a, 'b> core[ef7e3446cee7ff23]::ops::function::Fn<(&'a std[5d2d2d2a3de07169]::panic::PanicHookInfo<'b>,), Output = ()> + core[ef7e3446cee7ff23]::marker::Send + core[ef7e3446cee7ff23]::marker::Sync, &std[5d2d2d2a3de07169]::panic::PanicHookInfo)>>::call
   7:        0x10e54e95c - std::panicking::rust_panic_with_hook::hf0bd200963f84a79
   8:        0x10c558990 - std[5d2d2d2a3de07169]::panicking::begin_panic::<rustc_errors[6c9f61422b2b67fe]::ExplicitBug>::{closure#0}
   9:        0x10c5587e8 - std[5d2d2d2a3de07169]::sys::backtrace::__rust_end_short_backtrace::<std[5d2d2d2a3de07169]::panicking::begin_panic<rustc_errors[6c9f61422b2b67fe]::ExplicitBug>::{closure#0}, !>
  10:        0x110c4e5d8 - std[5d2d2d2a3de07169]::panicking::begin_panic::<rustc_errors[6c9f61422b2b67fe]::ExplicitBug>
  11:        0x10c549fcc - <rustc_errors[6c9f61422b2b67fe]::diagnostic::BugAbort as rustc_errors[6c9f61422b2b67fe]::diagnostic::EmissionGuarantee>::emit_producing_guarantee
  12:        0x10c167fe0 - <rustc_errors[6c9f61422b2b67fe]::DiagCtxtHandle>::span_bug::<rustc_span[a9b61c9ba68f3314]::span_encoding::Span, alloc[33d0a6a508eb5932]::string::String>
  13:        0x10c16c52c - rustc_middle[7d4f75877793c8e4]::util::bug::opt_span_bug_fmt::<rustc_span[a9b61c9ba68f3314]::span_encoding::Span>::{closure#0}
  14:        0x10c16c560 - rustc_middle[7d4f75877793c8e4]::ty::context::tls::with_opt::<rustc_middle[7d4f75877793c8e4]::util::bug::opt_span_bug_fmt<rustc_span[a9b61c9ba68f3314]::span_encoding::Span>::{closure#0}, !>::{closure#0}
  15:        0x10c16ba00 - rustc_middle[7d4f75877793c8e4]::ty::context::tls::with_context_opt::<rustc_middle[7d4f75877793c8e4]::ty::context::tls::with_opt<rustc_middle[7d4f75877793c8e4]::util::bug::opt_span_bug_fmt<rustc_span[a9b61c9ba68f3314]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
  16:        0x110c24198 - rustc_middle[7d4f75877793c8e4]::util::bug::span_bug_fmt::<rustc_span[a9b61c9ba68f3314]::span_encoding::Span>
  17:        0x10c0c88d4 - <rustc_codegen_llvm[36c236d002db6048]::context::CodegenCx as rustc_middle[7d4f75877793c8e4]::ty::layout::FnAbiOfHelpers>::handle_fn_abi_err
  18:        0x10c0bdd60 - <rustc_codegen_llvm[36c236d002db6048]::context::CodegenCx as rustc_middle[7d4f75877793c8e4]::ty::layout::FnAbiOf>::fn_abi_of_instance::{closure#0}
  19:        0x10c0ca760 - <rustc_codegen_llvm[36c236d002db6048]::context::CodegenCx as rustc_codegen_ssa[be5c3ef9ac00adbb]::traits::declare::PreDefineCodegenMethods>::predefine_fn
  20:        0x10c0b9110 - rustc_codegen_llvm[36c236d002db6048]::base::compile_codegen_unit::module_codegen
  21:        0x10c0b8804 - rustc_codegen_llvm[36c236d002db6048]::base::compile_codegen_unit
  22:        0x10c137078 - rustc_codegen_ssa[be5c3ef9ac00adbb]::base::codegen_crate::<rustc_codegen_llvm[36c236d002db6048]::LlvmCodegenBackend>
  23:        0x10c1cacf4 - <rustc_codegen_llvm[36c236d002db6048]::LlvmCodegenBackend as rustc_codegen_ssa[be5c3ef9ac00adbb]::traits::backend::CodegenBackend>::codegen_crate
  24:        0x10cd23e60 - <rustc_session[828553cc4c1b3304]::session::Session>::time::<alloc[33d0a6a508eb5932]::boxed::Box<dyn core[ef7e3446cee7ff23]::any::Any>, rustc_interface[fed0365793385749]::passes::start_codegen::{closure#0}>
  25:        0x10cdaa890 - rustc_interface[fed0365793385749]::passes::start_codegen
  26:        0x10cd4f0d0 - <rustc_interface[fed0365793385749]::queries::Linker>::codegen_and_build_linker
  27:        0x10c480764 - <rustc_middle[7d4f75877793c8e4]::ty::context::GlobalCtxt>::enter::<rustc_driver_impl[c0574d6a9003aa16]::run_compiler::{closure#0}::{closure#1}::{closure#6}, core[ef7e3446cee7ff23]::result::Result<core[ef7e3446cee7ff23]::option::Option<rustc_interface[fed0365793385749]::queries::Linker>, rustc_span[a9b61c9ba68f3314]::ErrorGuaranteed>>
  28:        0x10c45239c - <rustc_interface[fed0365793385749]::interface::Compiler>::enter::<rustc_driver_impl[c0574d6a9003aa16]::run_compiler::{closure#0}::{closure#1}, core[ef7e3446cee7ff23]::result::Result<core[ef7e3446cee7ff23]::option::Option<rustc_interface[fed0365793385749]::queries::Linker>, rustc_span[a9b61c9ba68f3314]::ErrorGuaranteed>>
  29:        0x10c49a5dc - rustc_span[a9b61c9ba68f3314]::create_session_globals_then::<core[ef7e3446cee7ff23]::result::Result<(), rustc_span[a9b61c9ba68f3314]::ErrorGuaranteed>, rustc_interface[fed0365793385749]::util::run_in_thread_with_globals<rustc_interface[fed0365793385749]::util::run_in_thread_pool_with_globals<rustc_interface[fed0365793385749]::interface::run_compiler<core[ef7e3446cee7ff23]::result::Result<(), rustc_span[a9b61c9ba68f3314]::ErrorGuaranteed>, rustc_driver_impl[c0574d6a9003aa16]::run_compiler::{closure#0}>::{closure#1}, core[ef7e3446cee7ff23]::result::Result<(), rustc_span[a9b61c9ba68f3314]::ErrorGuaranteed>>::{closure#0}, core[ef7e3446cee7ff23]::result::Result<(), rustc_span[a9b61c9ba68f3314]::ErrorGuaranteed>>::{closure#0}::{closure#0}::{closure#0}>
  30:        0x10c4820b8 - std[5d2d2d2a3de07169]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[fed0365793385749]::util::run_in_thread_with_globals<rustc_interface[fed0365793385749]::util::run_in_thread_pool_with_globals<rustc_interface[fed0365793385749]::interface::run_compiler<core[ef7e3446cee7ff23]::result::Result<(), rustc_span[a9b61c9ba68f3314]::ErrorGuaranteed>, rustc_driver_impl[c0574d6a9003aa16]::run_compiler::{closure#0}>::{closure#1}, core[ef7e3446cee7ff23]::result::Result<(), rustc_span[a9b61c9ba68f3314]::ErrorGuaranteed>>::{closure#0}, core[ef7e3446cee7ff23]::result::Result<(), rustc_span[a9b61c9ba68f3314]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[ef7e3446cee7ff23]::result::Result<(), rustc_span[a9b61c9ba68f3314]::ErrorGuaranteed>>
  31:        0x10c477eb8 - <<std[5d2d2d2a3de07169]::thread::Builder>::spawn_unchecked_<rustc_interface[fed0365793385749]::util::run_in_thread_with_globals<rustc_interface[fed0365793385749]::util::run_in_thread_pool_with_globals<rustc_interface[fed0365793385749]::interface::run_compiler<core[ef7e3446cee7ff23]::result::Result<(), rustc_span[a9b61c9ba68f3314]::ErrorGuaranteed>, rustc_driver_impl[c0574d6a9003aa16]::run_compiler::{closure#0}>::{closure#1}, core[ef7e3446cee7ff23]::result::Result<(), rustc_span[a9b61c9ba68f3314]::ErrorGuaranteed>>::{closure#0}, core[ef7e3446cee7ff23]::result::Result<(), rustc_span[a9b61c9ba68f3314]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[ef7e3446cee7ff23]::result::Result<(), rustc_span[a9b61c9ba68f3314]::ErrorGuaranteed>>::{closure#1} as core[ef7e3446cee7ff23]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  32:        0x10e558d2c - std::sys::pal::unix::thread::Thread::new::thread_start::h89c74db28defaaab
  33:        0x19fe5af94 - __pthread_joiner_wake

[matthiaskrgr]

probably duplicate of #118603

[spookyvision]

probably duplicate of #118603

the backtrace doesn't look identical, and neither does the repro, but that's all I can really say
edit: nevermind, missed the fn_abi_of_instance line in my output