ICE: hir: explicit panic

[matthiaskrgr]

auto-reduced (treereduce-rust):

fn main() {
    #[deprecated = "oh no"]
    #[cfg]
    0
}

original:

fn main() {
    #[deprecated = "oh no"]#[cfg]0
}

Version information

rustc 1.89.0-nightly (f3db63916 2025-06-17)
binary: rustc
commit-hash: f3db63916e541ff039ac3cd7364c2d612749b61b
commit-date: 2025-06-17
host: x86_64-unknown-linux-gnu
release: 1.89.0-nightly
LLVM version: 20.1.7

Possibly related line of code:

rust/compiler/rustc_hir/src/hir.rs

Lines 1347 to 1359 in f3db639

	#[inline]
	fn style(&self) -> AttrStyle {
	match &self {
	Attribute::Unparsed(u) => u.style,
	Attribute::Parsed(AttributeKind::DocComment { style, .. }) => *style,
	_ => panic!(),
	}
	}
	}
	// FIXME(fn_delegation): use function delegation instead of manually forwarding
	impl Attribute {

Command:
/home/matthias/.rustup/toolchains/master/bin/rustc

Program output

error: `cfg` is not followed by parentheses
 --> /tmp/icemaker_global_tempdir.TKUrz1r4Ivcl/rustc_testrunner_tmpdir_reporting.zI5VU3Z1dC85/mvce.rs:3:5
  |
3 |     #[cfg]
  |     ^^^^^^ help: expected syntax is: `cfg(/* predicate */)`

warning: attribute is ignored here
 --> /tmp/icemaker_global_tempdir.TKUrz1r4Ivcl/rustc_testrunner_tmpdir_reporting.zI5VU3Z1dC85/mvce.rs:2:5
  |
2 |     #[deprecated = "oh no"]
  |     ^^^^^^^^^^^^^^^^^^^^^^^
  |
  = note: `#[warn(unused_attributes)]` on by default


thread 'rustc' panicked at compiler/rustc_hir/src/hir.rs:1353:18:
explicit panic
stack backtrace:
   0:     0x71cd8eaff733 - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::hf6b8e560b2aaddbb
   1:     0x71cd8f202cb7 - core::fmt::write::h512536cc11a37f1b
   2:     0x71cd8eaf5263 - std::io::Write::write_fmt::h187d52edf76d8022
   3:     0x71cd8eaff592 - std::sys::backtrace::BacktraceLock::print::h35718979b39d7a33
   4:     0x71cd8eb0317a - std::panicking::default_hook::{{closure}}::hc9d1a33dc3084210
   5:     0x71cd8eb02cff - std::panicking::default_hook::hd6f81cf0b769b874
   6:     0x71cd8dbfbfd3 - std[9333bc5333c76994]::panicking::update_hook::<alloc[b28f35111b9cd925]::boxed::Box<rustc_driver_impl[9c8bc2fa3092ec28]::install_ice_hook::{closure#1}>>::{closure#0}
   7:     0x71cd8eb039e3 - std::panicking::rust_panic_with_hook::hfaae9da84f44c762
   8:     0x71cd8eb036da - std::panicking::begin_panic_handler::{{closure}}::h388c7963d93cd2b7
   9:     0x71cd8eaffc09 - std::sys::backtrace::__rust_end_short_backtrace::h47ca3b58dfe8fab9
  10:     0x71cd8eb033ad - __rustc[871f36a778bdfc9]::rust_begin_unwind
  11:     0x71cd8b295b00 - core::panicking::panic_fmt::h82d75da6f9ebf9a2
  12:     0x71cd8d5e5686 - core::panicking::panic_explicit::hd3af6f8734692b01
  13:     0x71cd8c6c5197 - <rustc_hir[b1a3cee99d54fa36]::hir::Attribute as rustc_ast[528e74ef4f3ffeec]::attr::AttributeExt>::style::panic_cold_explicit
  14:     0x71cd8dcbf9f3 - <rustc_hir[b1a3cee99d54fa36]::hir::Expr>::precedence::{closure#0}::{closure#0}
  15:     0x71cd911944cd - <rustc_hir_typeck[8542d075aaf85410]::fn_ctxt::FnCtxt>::precedence::{closure#0}.llvm.3780047115223620710.cold
  16:     0x71cd8fefa582 - <rustc_hir[b1a3cee99d54fa36]::hir::Expr>::precedence
  17:     0x71cd8df03f43 - <rustc_hir_typeck[8542d075aaf85410]::fn_ctxt::FnCtxt>::suggest_deref_ref_or_into
  18:     0x71cd8debff43 - <rustc_hir_typeck[8542d075aaf85410]::fn_ctxt::FnCtxt>::emit_type_mismatch_suggestions
  19:     0x71cd8dec54ae - <rustc_hir_typeck[8542d075aaf85410]::fn_ctxt::FnCtxt>::emit_coerce_suggestions
  20:     0x71cd8fb50daa - <rustc_hir_typeck[8542d075aaf85410]::fn_ctxt::FnCtxt>::check_expr_block
  21:     0x71cd8fbb24e7 - <rustc_hir_typeck[8542d075aaf85410]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  22:     0x71cd8fb58334 - rustc_hir_typeck[8542d075aaf85410]::check::check_fn
  23:     0x71cd903ec414 - rustc_hir_typeck[8542d075aaf85410]::typeck_with_inspect::{closure#0}
  24:     0x71cd903d8a30 - rustc_query_impl[335bf943c842fa2e]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[335bf943c842fa2e]::query_impl::typeck::dynamic_query::{closure#2}::{closure#0}, rustc_middle[85dd1ff96372fcb9]::query::erase::Erased<[u8; 8usize]>>
  25:     0x71cd8f440fee - rustc_query_system[f4098d1cf50ce8b4]::query::plumbing::try_execute_query::<rustc_query_impl[335bf943c842fa2e]::DynamicConfig<rustc_data_structures[f506b16921f7bc93]::vec_cache::VecCache<rustc_span[8686395707142f0d]::def_id::LocalDefId, rustc_middle[85dd1ff96372fcb9]::query::erase::Erased<[u8; 8usize]>, rustc_query_system[f4098d1cf50ce8b4]::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl[335bf943c842fa2e]::plumbing::QueryCtxt, false>
  26:     0x71cd8f440a49 - rustc_query_impl[335bf943c842fa2e]::query_impl::typeck::get_query_non_incr::__rust_end_short_backtrace
  27:     0x71cd8f449074 - rustc_hir_analysis[b968f598936cb41b]::check_crate
  28:     0x71cd8faadae5 - rustc_interface[f2bb11eed659e555]::passes::analysis
  29:     0x71cd8faad709 - rustc_query_impl[335bf943c842fa2e]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[335bf943c842fa2e]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[85dd1ff96372fcb9]::query::erase::Erased<[u8; 0usize]>>
  30:     0x71cd9026674e - rustc_query_system[f4098d1cf50ce8b4]::query::plumbing::try_execute_query::<rustc_query_impl[335bf943c842fa2e]::DynamicConfig<rustc_query_system[f4098d1cf50ce8b4]::query::caches::SingleCache<rustc_middle[85dd1ff96372fcb9]::query::erase::Erased<[u8; 0usize]>>, false, false, false>, rustc_query_impl[335bf943c842fa2e]::plumbing::QueryCtxt, false>
  31:     0x71cd90266336 - rustc_query_impl[335bf943c842fa2e]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  32:     0x71cd90472d9c - rustc_interface[f2bb11eed659e555]::passes::create_and_enter_global_ctxt::<core[b2a367d0a99567d4]::option::Option<rustc_interface[f2bb11eed659e555]::queries::Linker>, rustc_driver_impl[9c8bc2fa3092ec28]::run_compiler::{closure#0}::{closure#2}>::{closure#2}::{closure#0}
  33:     0x71cd90464149 - rustc_interface[f2bb11eed659e555]::interface::run_compiler::<(), rustc_driver_impl[9c8bc2fa3092ec28]::run_compiler::{closure#0}>::{closure#1}
  34:     0x71cd904174b2 - std[9333bc5333c76994]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[f2bb11eed659e555]::util::run_in_thread_with_globals<rustc_interface[f2bb11eed659e555]::util::run_in_thread_pool_with_globals<rustc_interface[f2bb11eed659e555]::interface::run_compiler<(), rustc_driver_impl[9c8bc2fa3092ec28]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
  35:     0x71cd90417196 - <<std[9333bc5333c76994]::thread::Builder>::spawn_unchecked_<rustc_interface[f2bb11eed659e555]::util::run_in_thread_with_globals<rustc_interface[f2bb11eed659e555]::util::run_in_thread_pool_with_globals<rustc_interface[f2bb11eed659e555]::interface::run_compiler<(), rustc_driver_impl[9c8bc2fa3092ec28]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core[b2a367d0a99567d4]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  36:     0x71cd904157bd - std::sys::pal::unix::thread::Thread::new::thread_start::hd9016145e0d739a0
  37:     0x71cd89ea57eb - <unknown>
  38:     0x71cd89f2918c - <unknown>
  39:                0x0 - <unknown>

error: the compiler unexpectedly panicked. this is a bug.

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 1.89.0-nightly (f3db63916 2025-06-17) running on x86_64-unknown-linux-gnu

query stack during panic:
#0 [typeck] type-checking `main`
#1 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to 1 previous error; 1 warning emitted

[matthiaskrgr]

caused by #134661

mvce

fn main() {
    #[deprecated]
    0
}

[fmease]

cc @dtolnay

[dtolnay]

Fix: #142759