Using `#[allow(dead_code)]` instead of `#[allow(unused)]` spuriously crashes the nightly compiler

[nastynaz]

Code

// this code causes the bug
#[derive(Debug, Deserialize)]
#[allow(dead_code)]
pub struct Response {
    symbol: String,
}

// this code fixes it (changing dead_code to unused)
#[derive(Debug, Deserialize)]
#[allow(unused)]
pub struct Response {
    symbol: String,
}

Meta

rustc --version --verbose:

rustc 1.88.0-nightly (4824c2bb7 2025-05-02)
binary: rustc
commit-hash: 4824c2bb7445cb2478aab0190c268c939d77a0f6
commit-date: 2025-05-02
host: aarch64-apple-darwin
release: 1.88.0-nightly
LLVM version: 20.1.2

Note that I'm using a pinned nightly version but this also happens on the latest nightly as of 8th June 2025.

Error output

thread 'rustc' panicked at /rustc/4824c2bb7445cb2478aab0190c268c939d77a0f6/compiler/rustc_query_system/src/dep_graph/serialized.rs:838:40:
explicit panic
stack backtrace:
   0:        0x10dcd5ac4 - std::backtrace::Backtrace::create::h694a2212a050bda1
   1:        0x10be5d898 - std[139e9a5b421481f3]::panicking::update_hook::<alloc[cd612748747c08a9]::boxed::Box<rustc_driver_impl[a00c2a7e81a682df]::install_ice_hook::{closure#1}>>::{closure#0}
   2:        0x10dcf3370 - std::panicking::rust_panic_with_hook::hcafd801c8ef3c354
   3:        0x10dcf2f64 - std::panicking::begin_panic_handler::{{closure}}::h798d6d21625f27ff
   4:        0x10dcee1d0 - std::sys::backtrace::__rust_end_short_backtrace::ha31ec5159ab9f0b1
   5:        0x10dcf2c2c - __rustc[8c94f3b18780567b]::rust_begin_unwind
   6:        0x11092ccb8 - core::panicking::panic_fmt::h46772ccf531b392c
   7:        0x11092cde8 - core::panicking::panic_explicit::h1f7e40b385e60192
   8:        0x110a7c56c - <rustc_query_system[91b4a0fe10381a5d]::query::plumbing::JobOwner<_, _> as core[13be161f60ab347d]::ops::drop::Drop>::drop::panic_cold_explicit
   9:        0x10d1bc9cc - <rustc_query_system[91b4a0fe10381a5d]::dep_graph::graph::DepGraphData<rustc_middle[31b2f980b346f9d1]::dep_graph::DepsType>>::try_mark_previous_green::<rustc_query_impl[f6eed1177e0094b6]::plumbing::QueryCtxt>
  10:        0x10d1bbf40 - <rustc_query_system[91b4a0fe10381a5d]::dep_graph::graph::DepGraphData<rustc_middle[31b2f980b346f9d1]::dep_graph::DepsType>>::try_mark_previous_green::<rustc_query_impl[f6eed1177e0094b6]::plumbing::QueryCtxt>
  11:        0x10d1bbf40 - <rustc_query_system[91b4a0fe10381a5d]::dep_graph::graph::DepGraphData<rustc_middle[31b2f980b346f9d1]::dep_graph::DepsType>>::try_mark_previous_green::<rustc_query_impl[f6eed1177e0094b6]::plumbing::QueryCtxt>
  12:        0x10d1bbf40 - <rustc_query_system[91b4a0fe10381a5d]::dep_graph::graph::DepGraphData<rustc_middle[31b2f980b346f9d1]::dep_graph::DepsType>>::try_mark_previous_green::<rustc_query_impl[f6eed1177e0094b6]::plumbing::QueryCtxt>
  13:        0x10d1bbd70 - <rustc_query_system[91b4a0fe10381a5d]::dep_graph::graph::DepGraphData<rustc_middle[31b2f980b346f9d1]::dep_graph::DepsType>>::try_mark_green::<rustc_query_impl[f6eed1177e0094b6]::plumbing::QueryCtxt>
  14:        0x10d2058a0 - rustc_query_system[91b4a0fe10381a5d]::query::plumbing::try_execute_query::<rustc_query_impl[f6eed1177e0094b6]::DynamicConfig<rustc_query_system[91b4a0fe10381a5d]::query::caches::DefIdCache<rustc_middle[31b2f980b346f9d1]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[f6eed1177e0094b6]::plumbing::QueryCtxt, true>
  15:        0x10d441d28 - rustc_query_impl[f6eed1177e0094b6]::query_impl::type_of::get_query_incr::__rust_end_short_backtrace
  16:        0x10d182f10 - <rustc_privacy[842bb0008e99664e]::ReachEverythingInTheInterfaceVisitor>::ty
  17:        0x10d18dfc4 - rustc_privacy[842bb0008e99664e]::effective_visibilities
  18:        0x10d435a34 - rustc_query_impl[f6eed1177e0094b6]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[f6eed1177e0094b6]::query_impl::effective_visibilities::dynamic_query::{closure#2}::{closure#0}, rustc_middle[31b2f980b346f9d1]::query::erase::Erased<[u8; 8usize]>>
  19:        0x10d213cf4 - rustc_query_system[91b4a0fe10381a5d]::query::plumbing::try_execute_query::<rustc_query_impl[f6eed1177e0094b6]::DynamicConfig<rustc_query_system[91b4a0fe10381a5d]::query::caches::SingleCache<rustc_middle[31b2f980b346f9d1]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[f6eed1177e0094b6]::plumbing::QueryCtxt, true>
  20:        0x10d431dfc - rustc_query_impl[f6eed1177e0094b6]::plumbing::force_from_dep_node::<rustc_query_impl[f6eed1177e0094b6]::DynamicConfig<rustc_query_system[91b4a0fe10381a5d]::query::caches::SingleCache<rustc_middle[31b2f980b346f9d1]::query::erase::Erased<[u8; 8usize]>>, false, false, false>>
  21:        0x10d3bb778 - <rustc_query_impl[f6eed1177e0094b6]::plumbing::query_callback<rustc_query_impl[f6eed1177e0094b6]::query_impl::effective_visibilities::QueryType>::{closure#0} as core[13be161f60ab347d]::ops::function::FnOnce<(rustc_middle[31b2f980b346f9d1]::ty::context::TyCtxt, rustc_query_system[91b4a0fe10381a5d]::dep_graph::dep_node::DepNode, rustc_query_system[91b4a0fe10381a5d]::dep_graph::serialized::SerializedDepNodeIndex)>>::call_once
  22:        0x10d1bbf98 - <rustc_query_system[91b4a0fe10381a5d]::dep_graph::graph::DepGraphData<rustc_middle[31b2f980b346f9d1]::dep_graph::DepsType>>::try_mark_previous_green::<rustc_query_impl[f6eed1177e0094b6]::plumbing::QueryCtxt>
  23:        0x10d1bbf40 - <rustc_query_system[91b4a0fe10381a5d]::dep_graph::graph::DepGraphData<rustc_middle[31b2f980b346f9d1]::dep_graph::DepsType>>::try_mark_previous_green::<rustc_query_impl[f6eed1177e0094b6]::plumbing::QueryCtxt>
  24:        0x10d1bbd70 - <rustc_query_system[91b4a0fe10381a5d]::dep_graph::graph::DepGraphData<rustc_middle[31b2f980b346f9d1]::dep_graph::DepsType>>::try_mark_green::<rustc_query_impl[f6eed1177e0094b6]::plumbing::QueryCtxt>
  25:        0x10d1f0c48 - rustc_query_system[91b4a0fe10381a5d]::query::plumbing::ensure_must_run::<rustc_query_impl[f6eed1177e0094b6]::DynamicConfig<rustc_data_structures[76a8846219ac0e1f]::vec_cache::VecCache<rustc_span[5b0c173a32852c17]::def_id::LocalDefId, rustc_middle[31b2f980b346f9d1]::query::erase::Erased<[u8; 8usize]>, rustc_query_system[91b4a0fe10381a5d]::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl[f6eed1177e0094b6]::plumbing::QueryCtxt>
  26:        0x10d46542c - rustc_query_impl[f6eed1177e0094b6]::query_impl::check_mod_type_wf::get_query_incr::__rust_end_short_backtrace
  27:        0x10c0ba29c - rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_slice::par_rec::<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_for_each_in<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, &[rustc_hir[511c18b7ef39e185]::hir_id::OwnerId], <rustc_middle[31b2f980b346f9d1]::ty::context::TyCtxt>::par_hir_for_each_module<rustc_hir_analysis[feea6d7370dffc9c]::check_crate::{closure#0}::{closure#0}>::{closure#0}>::{closure#0}::{closure#0}>
  28:        0x10c108020 - rayon_core[5f333c6480ed0f2a]::join::join_context::<rayon_core[5f333c6480ed0f2a]::join::join::call<(), rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_slice::par_rec<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_for_each_in<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, &[rustc_hir[511c18b7ef39e185]::hir_id::OwnerId], <rustc_middle[31b2f980b346f9d1]::ty::context::TyCtxt>::par_hir_for_each_module<rustc_hir_analysis[feea6d7370dffc9c]::check_crate::{closure#0}::{closure#0}>::{closure#0}>::{closure#0}::{closure#0}>::{closure#1}>::{closure#0}, rayon_core[5f333c6480ed0f2a]::join::join::call<(), rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_slice::par_rec<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_for_each_in<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, &[rustc_hir[511c18b7ef39e185]::hir_id::OwnerId], <rustc_middle[31b2f980b346f9d1]::ty::context::TyCtxt>::par_hir_for_each_module<rustc_hir_analysis[feea6d7370dffc9c]::check_crate::{closure#0}::{closure#0}>::{closure#0}>::{closure#0}::{closure#0}>::{closure#2}>::{closure#0}, (), ()>::{closure#0}
  29:        0x10c0ba46c - rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_slice::par_rec::<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_for_each_in<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, &[rustc_hir[511c18b7ef39e185]::hir_id::OwnerId], <rustc_middle[31b2f980b346f9d1]::ty::context::TyCtxt>::par_hir_for_each_module<rustc_hir_analysis[feea6d7370dffc9c]::check_crate::{closure#0}::{closure#0}>::{closure#0}>::{closure#0}::{closure#0}>
  30:        0x10c108020 - rayon_core[5f333c6480ed0f2a]::join::join_context::<rayon_core[5f333c6480ed0f2a]::join::join::call<(), rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_slice::par_rec<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_for_each_in<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, &[rustc_hir[511c18b7ef39e185]::hir_id::OwnerId], <rustc_middle[31b2f980b346f9d1]::ty::context::TyCtxt>::par_hir_for_each_module<rustc_hir_analysis[feea6d7370dffc9c]::check_crate::{closure#0}::{closure#0}>::{closure#0}>::{closure#0}::{closure#0}>::{closure#1}>::{closure#0}, rayon_core[5f333c6480ed0f2a]::join::join::call<(), rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_slice::par_rec<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_for_each_in<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, &[rustc_hir[511c18b7ef39e185]::hir_id::OwnerId], <rustc_middle[31b2f980b346f9d1]::ty::context::TyCtxt>::par_hir_for_each_module<rustc_hir_analysis[feea6d7370dffc9c]::check_crate::{closure#0}::{closure#0}>::{closure#0}>::{closure#0}::{closure#0}>::{closure#2}>::{closure#0}, (), ()>::{closure#0}
  31:        0x10c0ba46c - rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_slice::par_rec::<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_for_each_in<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, &[rustc_hir[511c18b7ef39e185]::hir_id::OwnerId], <rustc_middle[31b2f980b346f9d1]::ty::context::TyCtxt>::par_hir_for_each_module<rustc_hir_analysis[feea6d7370dffc9c]::check_crate::{closure#0}::{closure#0}>::{closure#0}>::{closure#0}::{closure#0}>
  32:        0x10c108020 - rayon_core[5f333c6480ed0f2a]::join::join_context::<rayon_core[5f333c6480ed0f2a]::join::join::call<(), rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_slice::par_rec<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_for_each_in<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, &[rustc_hir[511c18b7ef39e185]::hir_id::OwnerId], <rustc_middle[31b2f980b346f9d1]::ty::context::TyCtxt>::par_hir_for_each_module<rustc_hir_analysis[feea6d7370dffc9c]::check_crate::{closure#0}::{closure#0}>::{closure#0}>::{closure#0}::{closure#0}>::{closure#1}>::{closure#0}, rayon_core[5f333c6480ed0f2a]::join::join::call<(), rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_slice::par_rec<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_for_each_in<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, &[rustc_hir[511c18b7ef39e185]::hir_id::OwnerId], <rustc_middle[31b2f980b346f9d1]::ty::context::TyCtxt>::par_hir_for_each_module<rustc_hir_analysis[feea6d7370dffc9c]::check_crate::{closure#0}::{closure#0}>::{closure#0}>::{closure#0}::{closure#0}>::{closure#2}>::{closure#0}, (), ()>::{closure#0}
  33:        0x10c0ba46c - rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_slice::par_rec::<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_for_each_in<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, &[rustc_hir[511c18b7ef39e185]::hir_id::OwnerId], <rustc_middle[31b2f980b346f9d1]::ty::context::TyCtxt>::par_hir_for_each_module<rustc_hir_analysis[feea6d7370dffc9c]::check_crate::{closure#0}::{closure#0}>::{closure#0}>::{closure#0}::{closure#0}>
  34:        0x10c16ae0c - <rayon_core[5f333c6480ed0f2a]::job::StackJob<rayon_core[5f333c6480ed0f2a]::latch::SpinLatch, rayon_core[5f333c6480ed0f2a]::join::join_context::call_b<(), rayon_core[5f333c6480ed0f2a]::join::join::call<(), rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_slice::par_rec<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_for_each_in<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, &[rustc_hir[511c18b7ef39e185]::hir_id::OwnerId], <rustc_middle[31b2f980b346f9d1]::ty::context::TyCtxt>::par_hir_for_each_module<rustc_hir_analysis[feea6d7370dffc9c]::check_crate::{closure#0}::{closure#0}>::{closure#0}>::{closure#0}::{closure#0}>::{closure#2}>::{closure#0}>::{closure#0}, ()> as rayon_core[5f333c6480ed0f2a]::job::Job>::execute
  35:        0x11093e654 - <rayon_core[5f333c6480ed0f2a]::registry::WorkerThread>::wait_until_cold
  36:        0x10b48d288 - <rayon_core[5f333c6480ed0f2a]::registry::ThreadBuilder>::run
  37:        0x10be5211c - std[139e9a5b421481f3]::sys::backtrace::__rust_begin_short_backtrace::<<rayon_core[5f333c6480ed0f2a]::ThreadPoolBuilder>::build_scoped<rustc_interface[e22a78a7a7533c32]::util::run_in_thread_pool_with_globals<rustc_interface[e22a78a7a7533c32]::interface::run_compiler<(), rustc_driver_impl[a00c2a7e81a682df]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#5}::{closure#0}::{closure#0}, rustc_interface[e22a78a7a7533c32]::util::run_in_thread_pool_with_globals<rustc_interface[e22a78a7a7533c32]::interface::run_compiler<(), rustc_driver_impl[a00c2a7e81a682df]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#5}::{closure#0}::{closure#1}, ()>::{closure#0}::{closure#0}::{closure#0}, ()>
  38:        0x10be6652c - <<std[139e9a5b421481f3]::thread::Builder>::spawn_unchecked_<<rayon_core[5f333c6480ed0f2a]::ThreadPoolBuilder>::build_scoped<rustc_interface[e22a78a7a7533c32]::util::run_in_thread_pool_with_globals<rustc_interface[e22a78a7a7533c32]::interface::run_compiler<(), rustc_driver_impl[a00c2a7e81a682df]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#5}::{closure#0}::{closure#0}, rustc_interface[e22a78a7a7533c32]::util::run_in_thread_pool_with_globals<rustc_interface[e22a78a7a7533c32]::interface::run_compiler<(), rustc_driver_impl[a00c2a7e81a682df]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#5}::{closure#0}::{closure#1}, ()>::{closure#0}::{closure#0}::{closure#0}, ()>::{closure#1} as core[13be161f60ab347d]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  39:        0x10dcf58b0 - std::sys::pal::unix::thread::Thread::new::thread_start::hd3f65f7a2ff26076
  40:        0x19a3affa8 - __pthread_joiner_wake


rustc version: 1.88.0-nightly (4824c2bb7 2025-05-02)
platform: aarch64-apple-darwin

query stack during panic:
#0 [type_of] computing type of `latency::<impl at exchange/src/latency.rs:86:1: 86:56>::run_test::{opaque#0}`
#1 [effective_visibilities] checking effective visibilities
#2 [analysis] running analysis passes on this crate
end of query stack

I think It's due to me using #[allow(dead_code)] instead of `#[allow(unused)]

See backtrace below.

thread 'rustc' panicked at /rustc/4824c2bb7445cb2478aab0190c268c939d77a0f6/compiler/rustc_query_system/src/dep_graph/serialized.rs:838:40:
explicit panic
stack backtrace:
   0:        0x10dcedd38 - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::hac69eeb28672d7f4
   1:        0x10b303ff0 - core::fmt::write::h62747ee9da03639e
   2:        0x10dce2890 - std::io::Write::write_fmt::hb41bf8b129b9b749
   3:        0x10dcedbf8 - std::sys::backtrace::BacktraceLock::print::h19c46a5c8f67cbcd
   4:        0x10dcf2984 - std::panicking::default_hook::{{closure}}::hc54115d6ad7be6ee
   5:        0x10dcf2650 - std::panicking::default_hook::hdac5c763eaf94e72
   6:        0x10be5d688 - std[139e9a5b421481f3]::panicking::update_hook::<alloc[cd612748747c08a9]::boxed::Box<rustc_driver_impl[a00c2a7e81a682df]::install_ice_hook::{closure#1}>>::{closure#0}
   7:        0x10dcf3370 - std::panicking::rust_panic_with_hook::hcafd801c8ef3c354
   8:        0x10dcf2f64 - std::panicking::begin_panic_handler::{{closure}}::h798d6d21625f27ff
   9:        0x10dcee1d0 - std::sys::backtrace::__rust_end_short_backtrace::ha31ec5159ab9f0b1
  10:        0x10dcf2c2c - __rustc[8c94f3b18780567b]::rust_begin_unwind
  11:        0x11092ccb8 - core::panicking::panic_fmt::h46772ccf531b392c
  12:        0x11092cde8 - core::panicking::panic_explicit::h1f7e40b385e60192
  13:        0x110a7c56c - <rustc_query_system[91b4a0fe10381a5d]::query::plumbing::JobOwner<_, _> as core[13be161f60ab347d]::ops::drop::Drop>::drop::panic_cold_explicit
  14:        0x10d1bc9cc - <rustc_query_system[91b4a0fe10381a5d]::dep_graph::graph::DepGraphData<rustc_middle[31b2f980b346f9d1]::dep_graph::DepsType>>::try_mark_previous_green::<rustc_query_impl[f6eed1177e0094b6]::plumbing::QueryCtxt>
  15:        0x10d1bbf40 - <rustc_query_system[91b4a0fe10381a5d]::dep_graph::graph::DepGraphData<rustc_middle[31b2f980b346f9d1]::dep_graph::DepsType>>::try_mark_previous_green::<rustc_query_impl[f6eed1177e0094b6]::plumbing::QueryCtxt>
  16:        0x10d1bbf40 - <rustc_query_system[91b4a0fe10381a5d]::dep_graph::graph::DepGraphData<rustc_middle[31b2f980b346f9d1]::dep_graph::DepsType>>::try_mark_previous_green::<rustc_query_impl[f6eed1177e0094b6]::plumbing::QueryCtxt>
  17:        0x10d1bbf40 - <rustc_query_system[91b4a0fe10381a5d]::dep_graph::graph::DepGraphData<rustc_middle[31b2f980b346f9d1]::dep_graph::DepsType>>::try_mark_previous_green::<rustc_query_impl[f6eed1177e0094b6]::plumbing::QueryCtxt>
  18:        0x10d1bbd70 - <rustc_query_system[91b4a0fe10381a5d]::dep_graph::graph::DepGraphData<rustc_middle[31b2f980b346f9d1]::dep_graph::DepsType>>::try_mark_green::<rustc_query_impl[f6eed1177e0094b6]::plumbing::QueryCtxt>
  19:        0x10d2058a0 - rustc_query_system[91b4a0fe10381a5d]::query::plumbing::try_execute_query::<rustc_query_impl[f6eed1177e0094b6]::DynamicConfig<rustc_query_system[91b4a0fe10381a5d]::query::caches::DefIdCache<rustc_middle[31b2f980b346f9d1]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[f6eed1177e0094b6]::plumbing::QueryCtxt, true>
  20:        0x10d441d28 - rustc_query_impl[f6eed1177e0094b6]::query_impl::type_of::get_query_incr::__rust_end_short_backtrace
  21:        0x10d182f10 - <rustc_privacy[842bb0008e99664e]::ReachEverythingInTheInterfaceVisitor>::ty
  22:        0x10d18dfc4 - rustc_privacy[842bb0008e99664e]::effective_visibilities
  23:        0x10d435a34 - rustc_query_impl[f6eed1177e0094b6]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[f6eed1177e0094b6]::query_impl::effective_visibilities::dynamic_query::{closure#2}::{closure#0}, rustc_middle[31b2f980b346f9d1]::query::erase::Erased<[u8; 8usize]>>
  24:        0x10d213cf4 - rustc_query_system[91b4a0fe10381a5d]::query::plumbing::try_execute_query::<rustc_query_impl[f6eed1177e0094b6]::DynamicConfig<rustc_query_system[91b4a0fe10381a5d]::query::caches::SingleCache<rustc_middle[31b2f980b346f9d1]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[f6eed1177e0094b6]::plumbing::QueryCtxt, true>
  25:        0x10d431dfc - rustc_query_impl[f6eed1177e0094b6]::plumbing::force_from_dep_node::<rustc_query_impl[f6eed1177e0094b6]::DynamicConfig<rustc_query_system[91b4a0fe10381a5d]::query::caches::SingleCache<rustc_middle[31b2f980b346f9d1]::query::erase::Erased<[u8; 8usize]>>, false, false, false>>
  26:        0x10d3bb778 - <rustc_query_impl[f6eed1177e0094b6]::plumbing::query_callback<rustc_query_impl[f6eed1177e0094b6]::query_impl::effective_visibilities::QueryType>::{closure#0} as core[13be161f60ab347d]::ops::function::FnOnce<(rustc_middle[31b2f980b346f9d1]::ty::context::TyCtxt, rustc_query_system[91b4a0fe10381a5d]::dep_graph::dep_node::DepNode, rustc_query_system[91b4a0fe10381a5d]::dep_graph::serialized::SerializedDepNodeIndex)>>::call_once
  27:        0x10d1bbf98 - <rustc_query_system[91b4a0fe10381a5d]::dep_graph::graph::DepGraphData<rustc_middle[31b2f980b346f9d1]::dep_graph::DepsType>>::try_mark_previous_green::<rustc_query_impl[f6eed1177e0094b6]::plumbing::QueryCtxt>
  28:        0x10d1bbf40 - <rustc_query_system[91b4a0fe10381a5d]::dep_graph::graph::DepGraphData<rustc_middle[31b2f980b346f9d1]::dep_graph::DepsType>>::try_mark_previous_green::<rustc_query_impl[f6eed1177e0094b6]::plumbing::QueryCtxt>
  29:        0x10d1bbd70 - <rustc_query_system[91b4a0fe10381a5d]::dep_graph::graph::DepGraphData<rustc_middle[31b2f980b346f9d1]::dep_graph::DepsType>>::try_mark_green::<rustc_query_impl[f6eed1177e0094b6]::plumbing::QueryCtxt>
  30:        0x10d1f0c48 - rustc_query_system[91b4a0fe10381a5d]::query::plumbing::ensure_must_run::<rustc_query_impl[f6eed1177e0094b6]::DynamicConfig<rustc_data_structures[76a8846219ac0e1f]::vec_cache::VecCache<rustc_span[5b0c173a32852c17]::def_id::LocalDefId, rustc_middle[31b2f980b346f9d1]::query::erase::Erased<[u8; 8usize]>, rustc_query_system[91b4a0fe10381a5d]::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl[f6eed1177e0094b6]::plumbing::QueryCtxt>
  31:        0x10d46542c - rustc_query_impl[f6eed1177e0094b6]::query_impl::check_mod_type_wf::get_query_incr::__rust_end_short_backtrace
  32:        0x10c0ba29c - rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_slice::par_rec::<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_for_each_in<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, &[rustc_hir[511c18b7ef39e185]::hir_id::OwnerId], <rustc_middle[31b2f980b346f9d1]::ty::context::TyCtxt>::par_hir_for_each_module<rustc_hir_analysis[feea6d7370dffc9c]::check_crate::{closure#0}::{closure#0}>::{closure#0}>::{closure#0}::{closure#0}>
  33:        0x10c108020 - rayon_core[5f333c6480ed0f2a]::join::join_context::<rayon_core[5f333c6480ed0f2a]::join::join::call<(), rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_slice::par_rec<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_for_each_in<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, &[rustc_hir[511c18b7ef39e185]::hir_id::OwnerId], <rustc_middle[31b2f980b346f9d1]::ty::context::TyCtxt>::par_hir_for_each_module<rustc_hir_analysis[feea6d7370dffc9c]::check_crate::{closure#0}::{closure#0}>::{closure#0}>::{closure#0}::{closure#0}>::{closure#1}>::{closure#0}, rayon_core[5f333c6480ed0f2a]::join::join::call<(), rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_slice::par_rec<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_for_each_in<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, &[rustc_hir[511c18b7ef39e185]::hir_id::OwnerId], <rustc_middle[31b2f980b346f9d1]::ty::context::TyCtxt>::par_hir_for_each_module<rustc_hir_analysis[feea6d7370dffc9c]::check_crate::{closure#0}::{closure#0}>::{closure#0}>::{closure#0}::{closure#0}>::{closure#2}>::{closure#0}, (), ()>::{closure#0}
  34:        0x10c0ba46c - rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_slice::par_rec::<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_for_each_in<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, &[rustc_hir[511c18b7ef39e185]::hir_id::OwnerId], <rustc_middle[31b2f980b346f9d1]::ty::context::TyCtxt>::par_hir_for_each_module<rustc_hir_analysis[feea6d7370dffc9c]::check_crate::{closure#0}::{closure#0}>::{closure#0}>::{closure#0}::{closure#0}>
  35:        0x10c108020 - rayon_core[5f333c6480ed0f2a]::join::join_context::<rayon_core[5f333c6480ed0f2a]::join::join::call<(), rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_slice::par_rec<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_for_each_in<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, &[rustc_hir[511c18b7ef39e185]::hir_id::OwnerId], <rustc_middle[31b2f980b346f9d1]::ty::context::TyCtxt>::par_hir_for_each_module<rustc_hir_analysis[feea6d7370dffc9c]::check_crate::{closure#0}::{closure#0}>::{closure#0}>::{closure#0}::{closure#0}>::{closure#1}>::{closure#0}, rayon_core[5f333c6480ed0f2a]::join::join::call<(), rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_slice::par_rec<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_for_each_in<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, &[rustc_hir[511c18b7ef39e185]::hir_id::OwnerId], <rustc_middle[31b2f980b346f9d1]::ty::context::TyCtxt>::par_hir_for_each_module<rustc_hir_analysis[feea6d7370dffc9c]::check_crate::{closure#0}::{closure#0}>::{closure#0}>::{closure#0}::{closure#0}>::{closure#2}>::{closure#0}, (), ()>::{closure#0}
  36:        0x10c0ba46c - rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_slice::par_rec::<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_for_each_in<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, &[rustc_hir[511c18b7ef39e185]::hir_id::OwnerId], <rustc_middle[31b2f980b346f9d1]::ty::context::TyCtxt>::par_hir_for_each_module<rustc_hir_analysis[feea6d7370dffc9c]::check_crate::{closure#0}::{closure#0}>::{closure#0}>::{closure#0}::{closure#0}>
  37:        0x10c108020 - rayon_core[5f333c6480ed0f2a]::join::join_context::<rayon_core[5f333c6480ed0f2a]::join::join::call<(), rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_slice::par_rec<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_for_each_in<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, &[rustc_hir[511c18b7ef39e185]::hir_id::OwnerId], <rustc_middle[31b2f980b346f9d1]::ty::context::TyCtxt>::par_hir_for_each_module<rustc_hir_analysis[feea6d7370dffc9c]::check_crate::{closure#0}::{closure#0}>::{closure#0}>::{closure#0}::{closure#0}>::{closure#1}>::{closure#0}, rayon_core[5f333c6480ed0f2a]::join::join::call<(), rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_slice::par_rec<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_for_each_in<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, &[rustc_hir[511c18b7ef39e185]::hir_id::OwnerId], <rustc_middle[31b2f980b346f9d1]::ty::context::TyCtxt>::par_hir_for_each_module<rustc_hir_analysis[feea6d7370dffc9c]::check_crate::{closure#0}::{closure#0}>::{closure#0}>::{closure#0}::{closure#0}>::{closure#2}>::{closure#0}, (), ()>::{closure#0}
  38:        0x10c0ba46c - rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_slice::par_rec::<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_for_each_in<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, &[rustc_hir[511c18b7ef39e185]::hir_id::OwnerId], <rustc_middle[31b2f980b346f9d1]::ty::context::TyCtxt>::par_hir_for_each_module<rustc_hir_analysis[feea6d7370dffc9c]::check_crate::{closure#0}::{closure#0}>::{closure#0}>::{closure#0}::{closure#0}>
  39:        0x10c16ae0c - <rayon_core[5f333c6480ed0f2a]::job::StackJob<rayon_core[5f333c6480ed0f2a]::latch::SpinLatch, rayon_core[5f333c6480ed0f2a]::join::join_context::call_b<(), rayon_core[5f333c6480ed0f2a]::join::join::call<(), rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_slice::par_rec<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, rustc_data_structures[76a8846219ac0e1f]::sync::parallel::par_for_each_in<&rustc_hir[511c18b7ef39e185]::hir_id::OwnerId, &[rustc_hir[511c18b7ef39e185]::hir_id::OwnerId], <rustc_middle[31b2f980b346f9d1]::ty::context::TyCtxt>::par_hir_for_each_module<rustc_hir_analysis[feea6d7370dffc9c]::check_crate::{closure#0}::{closure#0}>::{closure#0}>::{closure#0}::{closure#0}>::{closure#2}>::{closure#0}>::{closure#0}, ()> as rayon_core[5f333c6480ed0f2a]::job::Job>::execute
  40:        0x11093e654 - <rayon_core[5f333c6480ed0f2a]::registry::WorkerThread>::wait_until_cold
  41:        0x10b48d288 - <rayon_core[5f333c6480ed0f2a]::registry::ThreadBuilder>::run
  42:        0x10be5211c - std[139e9a5b421481f3]::sys::backtrace::__rust_begin_short_backtrace::<<rayon_core[5f333c6480ed0f2a]::ThreadPoolBuilder>::build_scoped<rustc_interface[e22a78a7a7533c32]::util::run_in_thread_pool_with_globals<rustc_interface[e22a78a7a7533c32]::interface::run_compiler<(), rustc_driver_impl[a00c2a7e81a682df]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#5}::{closure#0}::{closure#0}, rustc_interface[e22a78a7a7533c32]::util::run_in_thread_pool_with_globals<rustc_interface[e22a78a7a7533c32]::interface::run_compiler<(), rustc_driver_impl[a00c2a7e81a682df]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#5}::{closure#0}::{closure#1}, ()>::{closure#0}::{closure#0}::{closure#0}, ()>
  43:        0x10be6652c - <<std[139e9a5b421481f3]::thread::Builder>::spawn_unchecked_<<rayon_core[5f333c6480ed0f2a]::ThreadPoolBuilder>::build_scoped<rustc_interface[e22a78a7a7533c32]::util::run_in_thread_pool_with_globals<rustc_interface[e22a78a7a7533c32]::interface::run_compiler<(), rustc_driver_impl[a00c2a7e81a682df]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#5}::{closure#0}::{closure#0}, rustc_interface[e22a78a7a7533c32]::util::run_in_thread_pool_with_globals<rustc_interface[e22a78a7a7533c32]::interface::run_compiler<(), rustc_driver_impl[a00c2a7e81a682df]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#5}::{closure#0}::{closure#1}, ()>::{closure#0}::{closure#0}::{closure#0}, ()>::{closure#1} as core[13be161f60ab347d]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  44:        0x10dcf58b0 - std::sys::pal::unix::thread::Thread::new::thread_start::hd3f65f7a2ff26076
  45:        0x19a3affa8 - __pthread_joiner_wake

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: please attach the file at `/Users/naz/dev/rust/brain/rustc-ice-2025-06-08T18_12_40-93225.txt` to your bug report

note: compiler flags: --crate-type lib -C embed-bitcode=no -C incremental=[REDACTED] -C strip=debuginfo -C target-cpu=native -Z threads=10

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

query stack during panic:
#0 [type_of] computing type of `latency::<impl at exchange/src/latency.rs:86:1: 86:56>::run_test::{opaque#0}`
#1 [effective_visibilities] checking effective visibilities
... and 1 other queries... use `env RUST_BACKTRACE=1` to see the full query stack
there was a panic while trying to force a dep node
try_mark_green dep node stack:
#0 check_well_formed(exchange[f3c8]::<REDACTED>::{impl#0})
#1 check_mod_type_wf(exchange[f3c8]::<REDACTED>)
end of try_mark_green dep node stack
error: could not compile `exchange` (lib)

[saethlin]

I cannot reproduce this panic. I think you over-minimized your example to something that doesn't provoke the bug.

[bjorn3]

I wonder if this is an incr comp issue. Does the broken example work if you run cargo clean first?

[nastynaz]

I realised it's actually a case of this issue: #141540 (comment)
It started happening again so my original hypothesis that changing dead_code to unused is incorrect. I turned off incremental compilation which fixed it. However this means I have much longer rebuild times.