[ICE]: incremental compilation error with evaluate_obligation

[YaxinCheng]

Code

Run the following test twice, the first time keep let _ = cloned_a.bar().await; effective (not commented out). Then comment it out, without running cargo clean, run it again with let results = cloned_a.bar().await; commented out.

This is a bug in incremental compilation, so you gotta trigger incremental compilation

use tokio::sync::oneshot;

pub struct A;

impl A {
    pub async fn bar(&self) -> anyhow::Result<Vec<usize>> {
        let mut receivers = Vec::new();
        let (_, rx) = oneshot::channel::<usize>();
        receivers.push(rx);

        // The async closure returning a Result, combined with mapping into try_join_all
        let received = receivers.into_iter().map(async |receiver| receiver.await);

        // Awaiting this forces the compiler to track the Map iterator across an await point
        let result = futures::future::try_join_all(received).await?;

        Ok(result)
    }
}

// The ICE is triggered during tests (or anywhere tokio::spawn is used)
#[tokio::test]
async fn test_trigger_ice() {
    let a = std::sync::Arc::new(A);
    let cloned_a = a.clone();

    // tokio::spawn requires the future to be `Send`.
    // When rustc tries to prove the `Map` iterator from acquire_full is `Send`, it panics.
    tokio::spawn(async move {
        // run it once with this code. Then comment this out
        let _ = cloned_a.bar().await;

        // then again with the code below commented out.
        // let results = cloned_a.bar().await;
    });
}

Meta

rustc --version --verbose:

rustc 1.97.0 (2d8144b78 2026-07-07)
binary: rustc
commit-hash: 2d8144b7880597b6e6d3dfd63a9a9efae3f533d3
commit-date: 2026-07-07
host: aarch64-apple-darwin
release: 1.97.0
LLVM version: 22.1.6

Error output

error: internal compiler error: encountered incremental compilation error with evaluate_obligation(60f016ea56cb4f11-f6f9439a770d03aa)
  |
  = note: please follow the instructions below to create a bug report with the provided information
  = note: for incremental compilation bugs, having a reproduction is vital
  = note: an ideal reproduction consists of the code before and some patch that then triggers the bug when applied and compiled again
  = note: as a workaround, you can run `cargo clean -p inc_comp_ice` or `cargo clean` to allow your project to compile

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: rustc 1.97.0 (2d8144b78 2026-07-07) running on aarch64-apple-darwin
note: compiler flags: -C embed-bitcode=no -C debuginfo=2 -C split-debuginfo=unpacked -C incremental=[REDACTED]
note: some of the compiler flags provided by cargo are hidden
query stack during panic:
#0 [evaluate_obligation] evaluating trait selection obligation `core::iter::adapters::map::Map<alloc::vec::into_iter::IntoIter<tokio::sync::oneshot::Receiver<usize>>, {async closure@src/lib.rs:13:50: 13:66}>: core::iter::traits::collect::IntoIterator`
#1 [type_op_prove_predicate] evaluating `type_op_prove_predicate` `ProvePredicate { predicate: Binder { value: TraitPredicate(<core::iter::adapters::map::Map<alloc::vec::into_iter::IntoIter<tokio::sync::oneshot::Receiver<usize>>, {async closure@src/lib.rs:13:50: 13:66}> as core::iter::traits::collect::IntoIterator>, polarity:Positive), bound_vars: [] } }`
#2 [mir_borrowck] borrow-checking `<impl at src/lib.rs:6:1: 6:7>::bar`
#3 [type_of_opaque] computing type of opaque `<impl at src/lib.rs:6:1: 6:7>::bar::{opaque#0}`
#4 [evaluate_obligation] evaluating trait selection obligation `{async block@src/lib.rs:30:18: 30:28}: core::marker::Send`
#5 [check_coroutine_obligations] verify auto trait bounds for coroutine interior type `test_trigger_ice`
#6 [mir_borrowck] borrow-checking `test_trigger_ice`
#7 [analysis] running analysis passes on crate `inc_comp_ice`
end of query stack

Backtrace

RUST_BACKTRACE=1 cargo build does not trigger it, only RUST_BACKTRACE=1 cargo test does

RUST_BACKTRACE=1 cargo test
   Compiling inc_comp_ice v0.1.0 (/Users/cheng/Developer/Rust/inc_comp_ice)
error: internal compiler error: encountered incremental compilation error with evaluate_obligation(6d1fbefc43bc968a-6f133a3d498f8932)
  |
  = note: please follow the instructions below to create a bug report with the provided information
  = note: for incremental compilation bugs, having a reproduction is vital
  = note: an ideal reproduction consists of the code before and some patch that then triggers the bug when applied and compiled again
  = note: as a workaround, you can run `cargo clean -p inc_comp_ice` or `cargo clean` to allow your project to compile


thread 'rustc' (3174755) panicked at /rustc-dev/8bab26f4f68e0e26f0bb7960be334d5b520ea452/compiler/rustc_middle/src/verify_ich.rs:82:9:
Found unstable fingerprints for evaluate_obligation(6d1fbefc43bc968a-6f133a3d498f8932): Ok(EvaluatedToOk)
stack backtrace:
   0: __rustc::rust_begin_unwind
   1: core::panicking::panic_fmt
   2: rustc_middle::verify_ich::incremental_verify_ich_failed
   3: rustc_middle::verify_ich::incremental_verify_ich::<rustc_middle::query::erase::ErasedData<[u8; 2]>>
   4: rustc_query_impl::execution::try_execute_query::<rustc_middle::query::caches::DefaultCache<rustc_type_ir::canonical::CanonicalQueryInput<rustc_middle::ty::context::TyCtxt, rustc_middle::ty::ParamEnvAnd<rustc_middle::ty::predicate::Predicate>>, rustc_middle::query::erase::ErasedData<[u8; 2]>>, true>
   5: <rustc_infer::infer::InferCtxt as rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt>::evaluate_obligation
   6: <rustc_infer::infer::InferCtxt as rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt>::evaluate_obligation_no_overflow
   7: <rustc_trait_selection::traits::fulfill::FulfillProcessor>::process_trait_obligation
   8: <rustc_trait_selection::traits::fulfill::FulfillProcessor as rustc_data_structures::obligation_forest::ObligationProcessor>::process_obligation
   9: <rustc_data_structures::obligation_forest::ObligationForest<rustc_trait_selection::traits::fulfill::PendingPredicateObligation>>::process_obligations::<rustc_trait_selection::traits::fulfill::FulfillProcessor>
  10: <rustc_trait_selection::traits::fulfill::FulfillmentContext<rustc_infer::traits::engine::ScrubbedTraitError> as rustc_infer::traits::engine::TraitEngine<rustc_infer::traits::engine::ScrubbedTraitError>>::try_evaluate_obligations
  11: <rustc_trait_selection::traits::fulfill::FulfillmentContext<rustc_infer::traits::engine::ScrubbedTraitError> as rustc_infer::traits::engine::TraitEngine<rustc_infer::traits::engine::ScrubbedTraitError>>::evaluate_obligations_error_on_ambiguity
  12: <rustc_trait_selection::traits::engine::ObligationCtxt>::make_canonicalized_query_response::<()>
  13: rustc_traits::type_op::type_op_prove_predicate
  14: rustc_query_impl::execution::try_execute_query::<rustc_middle::query::caches::DefaultCache<rustc_type_ir::canonical::CanonicalQueryInput<rustc_middle::ty::context::TyCtxt, rustc_middle::ty::ParamEnvAnd<rustc_middle::traits::query::type_op::ProvePredicate>>, rustc_middle::query::erase::ErasedData<[u8; 8]>>, true>
  15: <rustc_middle::traits::query::type_op::ProvePredicate as rustc_trait_selection::traits::query::type_op::QueryTypeOp>::perform_query
  16: <rustc_borrowck::type_check::TypeChecker>::fully_perform_op::<(), rustc_middle::ty::ParamEnvAnd<rustc_middle::traits::query::type_op::ProvePredicate>>
  17: <rustc_borrowck::type_check::TypeChecker>::normalize_and_prove_instantiated_predicates
  18: <rustc_borrowck::type_check::TypeChecker as rustc_middle::mir::visit::Visitor>::visit_const_operand
  19: <rustc_borrowck::type_check::TypeChecker as rustc_middle::mir::visit::Visitor>::visit_operand
  20: <rustc_borrowck::type_check::TypeChecker as rustc_middle::mir::visit::Visitor>::visit_terminator
  21: <rustc_borrowck::type_check::TypeChecker as rustc_middle::mir::visit::Visitor>::visit_body
  22: rustc_borrowck::type_check::type_check
  23: rustc_borrowck::borrowck_collect_region_constraints
  24: <rustc_borrowck::root_cx::BorrowCheckRootCtxt>::do_mir_borrowck
  25: rustc_borrowck::mir_borrowck
  26: rustc_query_impl::execution::try_execute_query::<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::ErasedData<[u8; 8]>, rustc_middle::dep_graph::graph::DepNodeIndex>, true>
  27: rustc_hir_analysis::collect::type_of::opaque::find_opaque_ty_constraints_for_rpit
  28: rustc_hir_analysis::collect::type_of::type_of_opaque
  29: rustc_query_impl::execution::try_execute_query::<rustc_middle::query::caches::DefIdCache<rustc_middle::query::erase::ErasedData<[u8; 8]>>, true>
  30: <rustc_trait_selection::traits::select::SelectionContext>::confirm_auto_impl_candidate::{closure#0}
  31: <rustc_trait_selection::traits::select::SelectionContext>::confirm_candidate
  32: <rustc_trait_selection::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}
  33: <rustc_trait_selection::traits::select::SelectionContext>::evaluation_probe::<<rustc_trait_selection::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}>
  34: <rustc_trait_selection::traits::select::SelectionContext>::evaluate_trait_predicate_recursively::{closure#0}::{closure#1}
  35: <rustc_trait_selection::traits::select::SelectionContext>::evaluate_trait_predicate_recursively
  36: <rustc_trait_selection::traits::select::SelectionContext>::evaluate_predicate_recursively::{closure#0}::{closure#0}
  37: <rustc_trait_selection::traits::select::SelectionContext>::evaluate_predicate_recursively
  38: <rustc_trait_selection::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}
  39: <rustc_trait_selection::traits::select::SelectionContext>::evaluation_probe::<<rustc_trait_selection::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}>
  40: <rustc_trait_selection::traits::select::SelectionContext>::evaluate_trait_predicate_recursively::{closure#0}::{closure#1}
  41: <rustc_trait_selection::traits::select::SelectionContext>::evaluate_trait_predicate_recursively
  42: <rustc_trait_selection::traits::select::SelectionContext>::evaluate_predicate_recursively::{closure#0}::{closure#0}
  43: <rustc_trait_selection::traits::select::SelectionContext>::evaluate_predicate_recursively
  44: <rustc_trait_selection::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}
  45: <rustc_trait_selection::traits::select::SelectionContext>::evaluation_probe::<<rustc_trait_selection::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}>
  46: <rustc_trait_selection::traits::select::SelectionContext>::evaluate_trait_predicate_recursively::{closure#0}::{closure#1}
  47: <rustc_trait_selection::traits::select::SelectionContext>::evaluate_trait_predicate_recursively
  48: <rustc_trait_selection::traits::select::SelectionContext>::evaluate_predicate_recursively::{closure#0}::{closure#0}
  49: <rustc_trait_selection::traits::select::SelectionContext>::evaluate_predicate_recursively
  50: <rustc_trait_selection::traits::select::SelectionContext>::evaluation_probe::<<rustc_trait_selection::traits::select::SelectionContext>::evaluate_root_obligation::{closure#0}>::{closure#0}
  51: <rustc_trait_selection::traits::select::SelectionContext>::evaluate_root_obligation
  52: rustc_traits::evaluate_obligation::evaluate_obligation
      [... omitted 1 frame ...]
  53: <rustc_infer::infer::InferCtxt as rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt>::evaluate_obligation
  54: <rustc_infer::infer::InferCtxt as rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt>::evaluate_obligation_no_overflow
  55: <rustc_trait_selection::traits::fulfill::FulfillProcessor>::process_trait_obligation
  56: <rustc_trait_selection::traits::fulfill::FulfillProcessor as rustc_data_structures::obligation_forest::ObligationProcessor>::process_obligation
  57: <rustc_data_structures::obligation_forest::ObligationForest<rustc_trait_selection::traits::fulfill::PendingPredicateObligation>>::process_obligations::<rustc_trait_selection::traits::fulfill::FulfillProcessor>
  58: <rustc_trait_selection::traits::fulfill::FulfillmentContext<rustc_trait_selection::traits::FulfillmentError> as rustc_infer::traits::engine::TraitEngine<rustc_trait_selection::traits::FulfillmentError>>::try_evaluate_obligations
  59: <rustc_trait_selection::traits::fulfill::FulfillmentContext<rustc_trait_selection::traits::FulfillmentError> as rustc_infer::traits::engine::TraitEngine<rustc_trait_selection::traits::FulfillmentError>>::evaluate_obligations_error_on_ambiguity
  60: rustc_hir_analysis::check::check::check_coroutine_obligations
      [... omitted 6 frames ...]
  61: <rustc_middle::ty::context::TyCtxt>::par_hir_body_owners::<rustc_interface::passes::run_required_analyses::{closure#2}::{closure#0}>::{closure#0}
  62: rustc_interface::passes::analysis
  63: rustc_query_impl::execution::try_execute_query::<rustc_middle::query::caches::SingleCache<rustc_middle::query::erase::ErasedData<[u8; 0]>>, true>
  64: rustc_interface::passes::create_and_enter_global_ctxt::<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure#2}>
  65: rustc_interface::interface::run_compiler::<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

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: rustc 1.97.1 (8bab26f4f 2026-07-14) running on aarch64-apple-darwin

note: compiler flags: -C embed-bitcode=no -C debuginfo=2 -C split-debuginfo=unpacked -C incremental=[REDACTED]

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

query stack during panic:
#0 [evaluate_obligation] evaluating trait selection obligation `core::iter::adapters::map::Map<alloc::vec::into_iter::IntoIter<tokio::sync::oneshot::Receiver<usize>>, {async closure@src/lib.rs:12:50: 12:66}>: core::iter::traits::collect::IntoIterator`
#1 [type_op_prove_predicate] evaluating `type_op_prove_predicate` `ProvePredicate { predicate: Binder { value: TraitPredicate(<core::iter::adapters::map::Map<alloc::vec::into_iter::IntoIter<tokio::sync::oneshot::Receiver<usize>>, {async closure@src/lib.rs:12:50: 12:66}> as core::iter::traits::collect::IntoIterator>, polarity:Positive), bound_vars: [] } }`
#2 [mir_borrowck] borrow-checking `<impl at src/lib.rs:5:1: 5:7>::bar`
#3 [type_of_opaque] computing type of opaque `<impl at src/lib.rs:5:1: 5:7>::bar::{opaque#0}`
#4 [evaluate_obligation] evaluating trait selection obligation `{async block@src/lib.rs:29:18: 29:28}: core::marker::Send`
#5 [check_coroutine_obligations] verify auto trait bounds for coroutine interior type `test_trigger_ice`
#6 [analysis] running analysis passes on crate `inc_comp_ice`
end of query stack
there was a panic while trying to force a dep node
try_mark_green dep node stack:
#0 mir_borrowck(inc_comp_ice[5cd8]::test_trigger_ice#1)
end of try_mark_green dep node stack
warning: unused variable: `labels`
  --> src/lib.rs:34:13
   |
34 |         let labels = cloned_pool.bar().await;
   |             ^^^^^^ help: if this is intentional, prefix it with an underscore: `_labels`
   |
   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default

warning: `inc_comp_ice` (lib test) generated 1 warning
error: could not compile `inc_comp_ice` (lib test) due to 1 previous error; 1 warning emitted

[YaxinCheng]

Just tested on the newest version, and this is still reproducible

$ rustc --version --verbose
rustc 1.97.1 (8bab26f4f 2026-07-14)
binary: rustc
commit-hash: 8bab26f4f68e0e26f0bb7960be334d5b520ea452
commit-date: 2026-07-14
host: aarch64-apple-darwin
release: 1.97.1
LLVM version: 22.1.6

[pacak]

struct J<I>(I);

impl<I> std::future::Future for J<I>
where
    I: IntoIterator,
{
    type Output = ();
    fn poll(
        self: std::pin::Pin<&mut Self>,
        _: &mut std::task::Context<'_>,
    ) -> std::task::Poll<Self::Output> {
        loop {}
    }
}

fn spawn<F: std::future::Future + Send>(_: F) {}

async fn bar() {
    J([std::future::ready(())].into_iter().map(async |r| r.await)).await;
}

#[test]
fn t() {
    spawn(async {
        // # AAA
        let _ = bar().await;

        // # BBB
        // let results = bar().await;
    });
}

[dominic-r]

I hit what looks like the same ICE on rustc 1.98.0 (88d9e12ae 2026-08-18) on aarch64-apple-darwin.

The panic was:

Found unstable fingerprints for evaluate_obligation(...): Ok(EvaluatedToOk)

The query stack was evaluating sqlx_postgres::type_info::PgTypeKind: Send / PgArguments: Send, and the failure happened while forcing incremental dep nodes for an async function in authentik.

This occurred during a normal incremental build. The build then failed with exit code 101.

Here's the full backtrace:

backtrace

error[E0599]: no method named `as_str` found for enum `std::option::Option<T>` in the current scope
    --> src/outpost/proxy/application/handlers/mod.rs:215:57
     |
 215 |     let client_secret = Some(app.provider.client_secret.as_str())
     |                                                         ^^^^^^ method not found in `std::option::Option<std::string::String>`
     |
note: the method `as_str` exists on the type `std::string::String`
    --> /nix/store/fr8fd2zx3ww8y660c9vmbk47c9psnv9s-rust-default-1.98.0/lib/rustlib/src/rust/library/alloc/src/string.rs:1057:5
     |
1057 |     pub const fn as_str(&self) -> &str {
     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
help: consider using `Option::expect` to unwrap the `std::string::String` value, panicking if the value is an `Option::None`
     |
 215 |     let client_secret = Some(app.provider.client_secret.expect("REASON").as_str())
     |                                                        +++++++++++++++++

error: internal compiler error: encountered incremental compilation error with evaluate_obligation(1200709947bc02f-d1c2b3df5a7c038a)
  |
  = note: please follow the instructions below to create a bug report with the provided information
  = note: for incremental compilation bugs, having a reproduction is vital
  = note: an ideal reproduction consists of the code before and some patch that then triggers the bug when applied and compiled again
  = note: as a workaround, you can run `cargo clean -p authentik` or `cargo clean` to allow your project to compile


thread 'rustc' (12357516) panicked at /rustc-dev/88d9e12ae178fab0fb5cc050a94da85685d449ea/compiler/rustc_middle/src/verify_ich.rs:82:9:
Found unstable fingerprints for evaluate_obligation(1200709947bc02f-d1c2b3df5a7c038a): Ok(EvaluatedToOk)
stack backtrace:
   0:        0x10ae0a88c - <<std[55d473a4219306f9]::sys::backtrace::BacktraceLock>::print::DisplayBacktrace as core[ff995cfa4774f676]::fmt::Display>::fmt
   1:        0x1080d7ce0 - core[ff995cfa4774f676]::fmt::write
   2:        0x10ae215ec - <std[55d473a4219306f9]::sys::stdio::unix::Stderr as std[55d473a4219306f9]::io::Write>::write_fmt
   3:        0x10addf1b8 - std[55d473a4219306f9]::panicking::default_hook::{closure#0}
   4:        0x10adfbd2c - std[55d473a4219306f9]::panicking::default_hook
   5:        0x108cc8324 - std[55d473a4219306f9]::panicking::update_hook::<alloc[4eb3ed5aa5d39689]::boxed::Box<rustc_driver_impl[d837514a467b1e39]::install_ice_hook::{closure#1}>>::{closure#0}
   6:        0x10adfc2f8 - std[55d473a4219306f9]::panicking::panic_with_hook
   7:        0x10addf23c - std[55d473a4219306f9]::panicking::panic_handler::{closure#0}
   8:        0x10add3b60 - std[55d473a4219306f9]::sys::backtrace::__rust_end_short_backtrace::<std[55d473a4219306f9]::panicking::panic_handler::{closure#0}, !>
   9:        0x10ade0764 - __rustc[4b1ee1ef74718a7b]::rust_begin_unwind
  10:        0x10aec6760 - core[ff995cfa4774f676]::panicking::panic_fmt
  11:        0x10afa7040 - rustc_middle[215fa6b0e72bc498]::verify_ich::incremental_verify_ich_failed
  12:        0x10a1ba90c - rustc_middle[215fa6b0e72bc498]::verify_ich::incremental_verify_ich::<rustc_middle[215fa6b0e72bc498]::query::erase::ErasedData<[u8; 2usize]>>
  13:        0x10a23274c - rustc_query_impl[c18d306eff432224]::execution::try_execute_query::<rustc_middle[215fa6b0e72bc498]::query::caches::DefaultCache<rustc_type_ir[afbe2b830dcfad17]::canonical::CanonicalQueryInput<rustc_middle[215fa6b0e72bc498]::ty::context::TyCtxt, rustc_middle[215fa6b0e72bc498]::ty::ParamEnvAnd<rustc_middle[215fa6b0e72bc498]::ty::predicate::Predicate>>, rustc_middle[215fa6b0e72bc498]::query::erase::ErasedData<[u8; 2usize]>>, true>
  14:        0x10a3d5960 - rustc_query_impl[c18d306eff432224]::query_impl::evaluate_obligation::execute_query_incr::__rust_end_short_backtrace
  15:        0x10ab880b8 - <rustc_infer[f11e75b4ba45b8c3]::infer::InferCtxt as rustc_trait_selection[e27d2d47e01dbefd]::traits::query::evaluate_obligation::InferCtxtExt>::evaluate_obligation
  16:        0x10ab88474 - <rustc_infer[f11e75b4ba45b8c3]::infer::InferCtxt as rustc_trait_selection[e27d2d47e01dbefd]::traits::query::evaluate_obligation::InferCtxtExt>::evaluate_obligation_no_overflow
  17:        0x10aaf219c - <rustc_trait_selection[e27d2d47e01dbefd]::traits::fulfill::FulfillProcessor>::process_trait_obligation
  18:        0x10aba614c - <rustc_trait_selection[e27d2d47e01dbefd]::traits::fulfill::FulfillProcessor as rustc_data_structures[bf6a780fe89470b2]::obligation_forest::ObligationProcessor>::process_obligation
  19:        0x10a9159fc - <rustc_data_structures[bf6a780fe89470b2]::obligation_forest::ObligationForest<rustc_trait_selection[e27d2d47e01dbefd]::traits::fulfill::PendingPredicateObligation>>::process_obligations::<rustc_trait_selection[e27d2d47e01dbefd]::traits::fulfill::FulfillProcessor>
  20:        0x10ab93c20 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::fulfill::FulfillmentContext<rustc_infer[f11e75b4ba45b8c3]::traits::engine::ScrubbedTraitError> as rustc_infer[f11e75b4ba45b8c3]::traits::engine::TraitEngine<rustc_infer[f11e75b4ba45b8c3]::traits::engine::ScrubbedTraitError>>::try_evaluate_obligations
  21:        0x10ac32954 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::fulfill::FulfillmentContext<rustc_infer[f11e75b4ba45b8c3]::traits::engine::ScrubbedTraitError> as rustc_infer[f11e75b4ba45b8c3]::traits::engine::TraitEngine<rustc_infer[f11e75b4ba45b8c3]::traits::engine::ScrubbedTraitError>>::evaluate_obligations_error_on_ambiguity
  22:        0x10ac416f8 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::engine::ObligationCtxt>::make_canonicalized_query_response::<()>
  23:        0x10ac6d9b4 - rustc_traits[b1dff865c6ac3537]::type_op::type_op_prove_predicate
  24:        0x10a239f1c - rustc_query_impl[c18d306eff432224]::execution::try_execute_query::<rustc_middle[215fa6b0e72bc498]::query::caches::DefaultCache<rustc_type_ir[afbe2b830dcfad17]::canonical::CanonicalQueryInput<rustc_middle[215fa6b0e72bc498]::ty::context::TyCtxt, rustc_middle[215fa6b0e72bc498]::ty::ParamEnvAnd<rustc_middle[215fa6b0e72bc498]::traits::query::type_op::ProvePredicate>>, rustc_middle[215fa6b0e72bc498]::query::erase::ErasedData<[u8; 8usize]>>, true>
  25:        0x10a3e32c0 - rustc_query_impl[c18d306eff432224]::query_impl::type_op_prove_predicate::execute_query_incr::__rust_end_short_backtrace
  26:        0x10ab894e8 - <rustc_middle[215fa6b0e72bc498]::traits::query::type_op::ProvePredicate as rustc_trait_selection[e27d2d47e01dbefd]::traits::query::type_op::QueryTypeOp>::perform_query
  27:        0x10854c5ac - <rustc_borrowck[37c42a3bda0c6e1]::type_check::TypeChecker>::fully_perform_op::<(), rustc_middle[215fa6b0e72bc498]::ty::ParamEnvAnd<rustc_middle[215fa6b0e72bc498]::traits::query::type_op::ProvePredicate>>
  28:        0x1086977bc - <rustc_borrowck[37c42a3bda0c6e1]::type_check::TypeChecker>::normalize_and_prove_instantiated_predicates
  29:        0x10875ce84 - <rustc_borrowck[37c42a3bda0c6e1]::type_check::TypeChecker as rustc_middle[215fa6b0e72bc498]::mir::visit::Visitor>::visit_const_operand
  30:        0x108757d28 - <rustc_borrowck[37c42a3bda0c6e1]::type_check::TypeChecker as rustc_middle[215fa6b0e72bc498]::mir::visit::Visitor>::visit_operand
  31:        0x108759920 - <rustc_borrowck[37c42a3bda0c6e1]::type_check::TypeChecker as rustc_middle[215fa6b0e72bc498]::mir::visit::Visitor>::visit_terminator
  32:        0x1087531f4 - <rustc_borrowck[37c42a3bda0c6e1]::type_check::TypeChecker as rustc_middle[215fa6b0e72bc498]::mir::visit::Visitor>::visit_body
  33:        0x108705e3c - rustc_borrowck[37c42a3bda0c6e1]::type_check::type_check
  34:        0x10868c660 - <rustc_borrowck[37c42a3bda0c6e1]::root_cx::BorrowCheckRootCtxt>::do_mir_borrowck
  35:        0x108676920 - rustc_borrowck[37c42a3bda0c6e1]::mir_borrowck
  36:        0x10a1d721c - rustc_query_impl[c18d306eff432224]::execution::try_execute_query::<rustc_data_structures[bf6a780fe89470b2]::vec_cache::VecCache<rustc_span[faf9d2f0fee7bbf8]::def_id::LocalDefId, rustc_middle[215fa6b0e72bc498]::query::erase::ErasedData<[u8; 8usize]>, rustc_middle[215fa6b0e72bc498]::dep_graph::graph::DepNodeIndex>, true>
  37:        0x10a3bf438 - rustc_query_impl[c18d306eff432224]::query_impl::mir_borrowck::execute_query_incr::__rust_end_short_backtrace
  38:        0x109093d88 - rustc_hir_analysis[2b3d57c58dd79456]::collect::type_of::opaque::find_opaque_ty_constraints_for_rpit
  39:        0x109072b14 - rustc_hir_analysis[2b3d57c58dd79456]::collect::type_of::type_of_opaque
  40:        0x10a1f71b8 - rustc_query_impl[c18d306eff432224]::execution::try_execute_query::<rustc_middle[215fa6b0e72bc498]::query::caches::DefIdCache<rustc_middle[215fa6b0e72bc498]::query::erase::ErasedData<[u8; 8usize]>>, true>
  41:        0x10a3c62a0 - rustc_query_impl[c18d306eff432224]::query_impl::type_of_opaque::execute_query_incr::__rust_end_short_backtrace
  42:        0x10aa4a5b4 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::confirm_auto_impl_candidate::{closure#0}
  43:        0x10aab89ec - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::confirm_candidate
  44:        0x10aa418f4 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}
  45:        0x10a93bd90 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluation_probe::<<rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}>
  46:        0x10aa42c84 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively::{closure#0}::{closure#1}
  47:        0x10ab0aad8 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively
  48:        0x10aa42030 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_predicate_recursively::{closure#0}::{closure#0}
  49:        0x10ab07e94 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_predicate_recursively
  50:        0x10aa419ec - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}
  51:        0x10a93bd90 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluation_probe::<<rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}>
  52:        0x10aa42c84 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively::{closure#0}::{closure#1}
  53:        0x10ab0aad8 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively
  54:        0x10aa42030 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_predicate_recursively::{closure#0}::{closure#0}
  55:        0x10ab07e94 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_predicate_recursively
  56:        0x10aa419ec - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}
  57:        0x10a93bd90 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluation_probe::<<rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}>
  58:        0x10aa42c84 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively::{closure#0}::{closure#1}
  59:        0x10ab0aad8 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively
  60:        0x10aa42030 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_predicate_recursively::{closure#0}::{closure#0}
  61:        0x10ab07e94 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_predicate_recursively
  62:        0x10aa419ec - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}
  63:        0x10a93bd90 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluation_probe::<<rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}>
  64:        0x10aa42c84 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively::{closure#0}::{closure#1}
  65:        0x10ab0aad8 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively
  66:        0x10aa42030 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_predicate_recursively::{closure#0}::{closure#0}
  67:        0x10ab07e94 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_predicate_recursively
  68:        0x10aa419ec - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}
  69:        0x10a93bd90 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluation_probe::<<rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}>
  70:        0x10aa42c84 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively::{closure#0}::{closure#1}
  71:        0x10ab0aad8 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively
  72:        0x10aa42030 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_predicate_recursively::{closure#0}::{closure#0}
  73:        0x10ab07e94 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_predicate_recursively
  74:        0x10aa419ec - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}
  75:        0x10a93bd90 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluation_probe::<<rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}>
  76:        0x10aa42c84 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively::{closure#0}::{closure#1}
  77:        0x10ab0aad8 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively
  78:        0x10aa42030 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_predicate_recursively::{closure#0}::{closure#0}
  79:        0x10ab07e94 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_predicate_recursively
  80:        0x10aa419ec - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}
  81:        0x10a93bd90 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluation_probe::<<rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}>
  82:        0x10aa42c84 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively::{closure#0}::{closure#1}
  83:        0x10ab0aad8 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively
  84:        0x10aa42030 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_predicate_recursively::{closure#0}::{closure#0}
  85:        0x10ab07e94 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_predicate_recursively
  86:        0x10aa419ec - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}
  87:        0x10a93bd90 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluation_probe::<<rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}>
  88:        0x10aa42c84 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively::{closure#0}::{closure#1}
  89:        0x10ab0aad8 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively
  90:        0x10aa42030 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_predicate_recursively::{closure#0}::{closure#0}
  91:        0x10ab07e94 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_predicate_recursively
  92:        0x10aa419ec - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}
  93:        0x10a93bd90 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluation_probe::<<rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}>
  94:        0x10aa42c84 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively::{closure#0}::{closure#1}
  95:        0x10ab0aad8 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively
  96:        0x10aa42030 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_predicate_recursively::{closure#0}::{closure#0}
  97:        0x10ab07e94 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_predicate_recursively
  98:        0x10aa419ec - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}
  99:        0x10a93bd90 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluation_probe::<<rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}>
 100:        0x10aa42c84 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively::{closure#0}::{closure#1}
 101:        0x10ab0aad8 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively
 102:        0x10aa42030 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_predicate_recursively::{closure#0}::{closure#0}
 103:        0x10ab07e94 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_predicate_recursively
 104:        0x10aa419ec - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}
 105:        0x10a93bd90 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluation_probe::<<rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}>
 106:        0x10aa42c84 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively::{closure#0}::{closure#1}
 107:        0x10ab0aad8 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively
 108:        0x10aa42030 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_predicate_recursively::{closure#0}::{closure#0}
 109:        0x10ab07e94 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_predicate_recursively
 110:        0x10aa419ec - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}
 111:        0x10a93bd90 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluation_probe::<<rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}>
 112:        0x10aa42c84 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively::{closure#0}::{closure#1}
 113:        0x10ab0aad8 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively
 114:        0x10aa42030 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_predicate_recursively::{closure#0}::{closure#0}
 115:        0x10ab07e94 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_predicate_recursively
 116:        0x10aa419ec - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}
 117:        0x10a93bd90 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluation_probe::<<rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}>
 118:        0x10aa42c84 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively::{closure#0}::{closure#1}
 119:        0x10ab0aad8 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively
 120:        0x10aa42030 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_predicate_recursively::{closure#0}::{closure#0}
 121:        0x10ab07e94 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_predicate_recursively
 122:        0x10aa419ec - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}
 123:        0x10a93bd90 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluation_probe::<<rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}>
 124:        0x10aa42c84 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively::{closure#0}::{closure#1}
 125:        0x10ab0aad8 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively
 126:        0x10aa42030 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_predicate_recursively::{closure#0}::{closure#0}
 127:        0x10ab07e94 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_predicate_recursively
 128:        0x10aa419ec - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}
 129:        0x10a93bd90 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluation_probe::<<rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}>
 130:        0x10aa42c84 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively::{closure#0}::{closure#1}
 131:        0x10ab0aad8 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively
 132:        0x10aa42030 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_predicate_recursively::{closure#0}::{closure#0}
 133:        0x10ab07e94 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_predicate_recursively
 134:        0x10aa419ec - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}
 135:        0x10ab084e4 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::candidate_from_obligation_no_cache
 136:        0x10ab05c64 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::candidate_from_obligation
 137:        0x10aa55ac4 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::select::SelectionContext>::poly_select::{closure#0}
 138:        0x10aaf220c - <rustc_trait_selection[e27d2d47e01dbefd]::traits::fulfill::FulfillProcessor>::process_trait_obligation
 139:        0x10aba614c - <rustc_trait_selection[e27d2d47e01dbefd]::traits::fulfill::FulfillProcessor as rustc_data_structures[bf6a780fe89470b2]::obligation_forest::ObligationProcessor>::process_obligation
 140:        0x10a9159fc - <rustc_data_structures[bf6a780fe89470b2]::obligation_forest::ObligationForest<rustc_trait_selection[e27d2d47e01dbefd]::traits::fulfill::PendingPredicateObligation>>::process_obligations::<rustc_trait_selection[e27d2d47e01dbefd]::traits::fulfill::FulfillProcessor>
 141:        0x10937dae0 - <rustc_trait_selection[e27d2d47e01dbefd]::traits::fulfill::FulfillmentContext<rustc_trait_selection[e27d2d47e01dbefd]::traits::FulfillmentError> as rustc_infer[f11e75b4ba45b8c3]::traits::engine::TraitEngine<rustc_trait_selection[e27d2d47e01dbefd]::traits::FulfillmentError>>::try_evaluate_obligations
 142:        0x1092dbc68 - <rustc_hir_typeck[b45707f09bab99d9]::fn_ctxt::FnCtxt>::check_argument_types
 143:        0x10929c698 - <rustc_hir_typeck[b45707f09bab99d9]::fn_ctxt::FnCtxt>::confirm_builtin_call
 144:        0x1092838f8 - <rustc_hir_typeck[b45707f09bab99d9]::fn_ctxt::FnCtxt>::check_expr_kind
 145:        0x1092992d8 - <rustc_hir_typeck[b45707f09bab99d9]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
 146:        0x1092dbf6c - <rustc_hir_typeck[b45707f09bab99d9]::fn_ctxt::FnCtxt>::check_argument_types
 147:        0x109280d98 - <rustc_hir_typeck[b45707f09bab99d9]::fn_ctxt::FnCtxt>::check_expr_kind
 148:        0x1092992d8 - <rustc_hir_typeck[b45707f09bab99d9]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
 149:        0x1092d50dc - <rustc_hir_typeck[b45707f09bab99d9]::fn_ctxt::FnCtxt>::check_decl
 150:        0x10924c5a0 - <rustc_hir_typeck[b45707f09bab99d9]::fn_ctxt::FnCtxt>::check_expr_block::{closure#0}
 151:        0x1092d93e4 - <rustc_hir_typeck[b45707f09bab99d9]::fn_ctxt::FnCtxt>::check_expr_block
 152:        0x1092992d8 - <rustc_hir_typeck[b45707f09bab99d9]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
 153:        0x10924ca04 - <rustc_hir_typeck[b45707f09bab99d9]::fn_ctxt::FnCtxt>::check_expr_block::{closure#0}
 154:        0x1092d93e4 - <rustc_hir_typeck[b45707f09bab99d9]::fn_ctxt::FnCtxt>::check_expr_block
 155:        0x1092992d8 - <rustc_hir_typeck[b45707f09bab99d9]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
 156:        0x10929720c - <rustc_hir_typeck[b45707f09bab99d9]::fn_ctxt::FnCtxt>::check_return_or_body_tail
 157:        0x10935e9e4 - rustc_hir_typeck[b45707f09bab99d9]::check::check_fn
 158:        0x109280898 - <rustc_hir_typeck[b45707f09bab99d9]::fn_ctxt::FnCtxt>::check_expr_kind
 159:        0x1092992d8 - <rustc_hir_typeck[b45707f09bab99d9]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
 160:        0x1092d50dc - <rustc_hir_typeck[b45707f09bab99d9]::fn_ctxt::FnCtxt>::check_decl
 161:        0x10924c5a0 - <rustc_hir_typeck[b45707f09bab99d9]::fn_ctxt::FnCtxt>::check_expr_block::{closure#0}
 162:        0x1092d93e4 - <rustc_hir_typeck[b45707f09bab99d9]::fn_ctxt::FnCtxt>::check_expr_block
 163:        0x1092992d8 - <rustc_hir_typeck[b45707f09bab99d9]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
 164:        0x109278034 - <rustc_hir_typeck[b45707f09bab99d9]::fn_ctxt::FnCtxt>::check_expr_kind
 165:        0x1092992d8 - <rustc_hir_typeck[b45707f09bab99d9]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
 166:        0x10924ca04 - <rustc_hir_typeck[b45707f09bab99d9]::fn_ctxt::FnCtxt>::check_expr_block::{closure#0}
 167:        0x1092d93e4 - <rustc_hir_typeck[b45707f09bab99d9]::fn_ctxt::FnCtxt>::check_expr_block
 168:        0x1092992d8 - <rustc_hir_typeck[b45707f09bab99d9]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
 169:        0x10929720c - <rustc_hir_typeck[b45707f09bab99d9]::fn_ctxt::FnCtxt>::check_return_or_body_tail
 170:        0x10935e9e4 - rustc_hir_typeck[b45707f09bab99d9]::check::check_fn
 171:        0x109280898 - <rustc_hir_typeck[b45707f09bab99d9]::fn_ctxt::FnCtxt>::check_expr_kind
 172:        0x1092992d8 - <rustc_hir_typeck[b45707f09bab99d9]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
 173:        0x10929720c - <rustc_hir_typeck[b45707f09bab99d9]::fn_ctxt::FnCtxt>::check_return_or_body_tail
 174:        0x10935e9e4 - rustc_hir_typeck[b45707f09bab99d9]::check::check_fn
 175:        0x109242aa4 - rustc_hir_typeck[b45707f09bab99d9]::typeck_with_inspect::{closure#0}
 176:        0x109269868 - rustc_hir_typeck[b45707f09bab99d9]::typeck_root
 177:        0x10a1d7578 - rustc_query_impl[c18d306eff432224]::execution::try_execute_query::<rustc_data_structures[bf6a780fe89470b2]::vec_cache::VecCache<rustc_span[faf9d2f0fee7bbf8]::def_id::LocalDefId, rustc_middle[215fa6b0e72bc498]::query::erase::ErasedData<[u8; 8usize]>, rustc_middle[215fa6b0e72bc498]::dep_graph::graph::DepNodeIndex>, true>
 178:        0x10a284b54 - rustc_query_impl[c18d306eff432224]::execution::force_query_dep_node::<rustc_data_structures[bf6a780fe89470b2]::vec_cache::VecCache<rustc_span[faf9d2f0fee7bbf8]::def_id::LocalDefId, rustc_middle[215fa6b0e72bc498]::query::erase::ErasedData<[u8; 8usize]>, rustc_middle[215fa6b0e72bc498]::dep_graph::graph::DepNodeIndex>>
 179:        0x10a5080b0 - <rustc_query_impl[c18d306eff432224]::dep_kind_vtables::make_dep_kind_vtable_for_query<rustc_query_impl[c18d306eff432224]::query_impl::typeck_root::VTableGetter>::{closure#0} as core[ff995cfa4774f676]::ops::function::FnOnce<(rustc_middle[215fa6b0e72bc498]::ty::context::TyCtxt, rustc_middle[215fa6b0e72bc498]::dep_graph::dep_node::DepNode, rustc_middle[215fa6b0e72bc498]::dep_graph::serialized::SerializedDepNodeIndex)>>::call_once
 180:        0x1099356c0 - <rustc_middle[215fa6b0e72bc498]::dep_graph::graph::DepGraphData>::try_mark_previous_green
 181:        0x109935650 - <rustc_middle[215fa6b0e72bc498]::dep_graph::graph::DepGraphData>::try_mark_previous_green
 182:        0x109935650 - <rustc_middle[215fa6b0e72bc498]::dep_graph::graph::DepGraphData>::try_mark_previous_green
 183:        0x109935650 - <rustc_middle[215fa6b0e72bc498]::dep_graph::graph::DepGraphData>::try_mark_previous_green
 184:        0x109935650 - <rustc_middle[215fa6b0e72bc498]::dep_graph::graph::DepGraphData>::try_mark_previous_green
 185:        0x109935650 - <rustc_middle[215fa6b0e72bc498]::dep_graph::graph::DepGraphData>::try_mark_previous_green
 186:        0x109935650 - <rustc_middle[215fa6b0e72bc498]::dep_graph::graph::DepGraphData>::try_mark_previous_green
 187:        0x1099353fc - <rustc_middle[215fa6b0e72bc498]::dep_graph::graph::DepGraphData>::try_mark_green
 188:        0x10a1f70a8 - rustc_query_impl[c18d306eff432224]::execution::try_execute_query::<rustc_middle[215fa6b0e72bc498]::query::caches::DefIdCache<rustc_middle[215fa6b0e72bc498]::query::erase::ErasedData<[u8; 8usize]>>, true>
 189:        0x10a3f2920 - rustc_query_impl[c18d306eff432224]::query_impl::type_of::execute_query_incr::__rust_end_short_backtrace
 190:        0x10a0d560c - <rustc_privacy[6f3a4c5883893a4b]::ReachEverythingInTheInterfaceVisitor>::ty
 191:        0x10a0cfb0c - rustc_privacy[6f3a4c5883893a4b]::effective_visibilities
 192:        0x10a205ae8 - rustc_query_impl[c18d306eff432224]::execution::try_execute_query::<rustc_middle[215fa6b0e72bc498]::query::caches::SingleCache<rustc_middle[215fa6b0e72bc498]::query::erase::ErasedData<[u8; 8usize]>>, true>
 193:        0x10a50c9c8 - <rustc_query_impl[c18d306eff432224]::dep_kind_vtables::make_dep_kind_vtable_for_query<rustc_query_impl[c18d306eff432224]::query_impl::effective_visibilities::VTableGetter>::{closure#0} as core[ff995cfa4774f676]::ops::function::FnOnce<(rustc_middle[215fa6b0e72bc498]::ty::context::TyCtxt, rustc_middle[215fa6b0e72bc498]::dep_graph::dep_node::DepNode, rustc_middle[215fa6b0e72bc498]::dep_graph::serialized::SerializedDepNodeIndex)>>::call_once
 194:        0x1099356c0 - <rustc_middle[215fa6b0e72bc498]::dep_graph::graph::DepGraphData>::try_mark_previous_green
 195:        0x1099353fc - <rustc_middle[215fa6b0e72bc498]::dep_graph::graph::DepGraphData>::try_mark_green
 196:        0x10a285e1c - rustc_query_impl[c18d306eff432224]::execution::ensure_can_skip_execution::<rustc_data_structures[bf6a780fe89470b2]::vec_cache::VecCache<rustc_hir_id[9aefcda4a9aedc84]::OwnerId, rustc_middle[215fa6b0e72bc498]::query::erase::ErasedData<[u8; 8usize]>, rustc_middle[215fa6b0e72bc498]::dep_graph::graph::DepNodeIndex>>
 197:        0x10a3ce0b8 - rustc_query_impl[c18d306eff432224]::query_impl::check_well_formed::execute_query_incr::__rust_end_short_backtrace
 198:        0x109048440 - rustc_hir_analysis[2b3d57c58dd79456]::check::wfcheck::check_type_wf
 199:        0x10a3c0628 - rustc_query_impl[c18d306eff432224]::query_impl::check_type_wf::invoke_provider_fn::__rust_begin_short_backtrace
 200:        0x10a200918 - rustc_query_impl[c18d306eff432224]::execution::try_execute_query::<rustc_middle[215fa6b0e72bc498]::query::caches::SingleCache<rustc_middle[215fa6b0e72bc498]::query::erase::ErasedData<[u8; 1usize]>>, true>
 201:        0x10a3c05b0 - rustc_query_impl[c18d306eff432224]::query_impl::check_type_wf::execute_query_incr::__rust_end_short_backtrace
 202:        0x108f9e2f0 - rustc_hir_analysis[2b3d57c58dd79456]::check_crate
 203:        0x109576594 - rustc_interface[852ca8b485215a98]::passes::analysis
 204:        0x10a1fb2ec - rustc_query_impl[c18d306eff432224]::execution::try_execute_query::<rustc_middle[215fa6b0e72bc498]::query::caches::SingleCache<rustc_middle[215fa6b0e72bc498]::query::erase::ErasedData<[u8; 0usize]>>, true>
 205:        0x10a3f2bd8 - rustc_query_impl[c18d306eff432224]::query_impl::analysis::execute_query_incr::__rust_end_short_backtrace
 206:        0x108c7f958 - rustc_interface[852ca8b485215a98]::passes::create_and_enter_global_ctxt::<core[ff995cfa4774f676]::option::Option<rustc_interface[852ca8b485215a98]::queries::Linker>, rustc_driver_impl[d837514a467b1e39]::run_compiler::{closure#0}::{closure#2}>
 207:        0x108ccb744 - rustc_interface[852ca8b485215a98]::interface::run_compiler::<(), rustc_driver_impl[d837514a467b1e39]::run_compiler::{closure#0}>::{closure#1}
 208:        0x108cc007c - std[55d473a4219306f9]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[852ca8b485215a98]::util::run_in_thread_with_globals<rustc_interface[852ca8b485215a98]::util::run_in_thread_pool_with_globals<rustc_interface[852ca8b485215a98]::interface::run_compiler<(), rustc_driver_impl[d837514a467b1e39]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
 209:        0x108cce128 - <std[55d473a4219306f9]::thread::lifecycle::spawn_unchecked<rustc_interface[852ca8b485215a98]::util::run_in_thread_with_globals<rustc_interface[852ca8b485215a98]::util::run_in_thread_pool_with_globals<rustc_interface[852ca8b485215a98]::interface::run_compiler<(), rustc_driver_impl[d837514a467b1e39]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core[ff995cfa4774f676]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
 210:        0x10ae0745c - <std[55d473a4219306f9]::sys::thread::unix::Thread>::new::thread_start
 211:        0x18098dd04 - __pthread_exit

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: rustc 1.98.0 (88d9e12ae 2026-08-18) running on aarch64-apple-darwin

note: compiler flags: --crate-type bin -C embed-bitcode=no -C debuginfo=2 -C split-debuginfo=unpacked -C incremental=[REDACTED] -C link-arg=-Wl,-rpath,/nix/store/2p7qr612c4382irfrwzy8sl8yhg4z3zc-python3-3.14.7/lib

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

query stack during panic:
#0 [evaluate_obligation] evaluating trait selection obligation `sqlx_postgres::type_info::PgTypeKind: core::marker::Send`
#1 [type_op_prove_predicate] evaluating `type_op_prove_predicate` `ProvePredicate { predicate: Binder { value: TraitPredicate(<sqlx_postgres::arguments::PgArguments as core::marker::Send>, polarity:Positive), bound_vars: [] } }`
... and 7 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_match(authentik[2e24]::outpost::proxy::application::{impl#0}::new)
#1 mir_built(authentik[2e24]::outpost::proxy::application::{impl#0}::new)
#2 has_ffi_unwind_calls(authentik[2e24]::outpost::proxy::application::{impl#0}::new)
#3 mir_promoted(authentik[2e24]::outpost::proxy::application::{impl#0}::new)
#4 mir_borrowck(authentik[2e24]::outpost::proxy::application::{impl#0}::new)
#5 type_of_opaque(authentik[2e24]::outpost::proxy::application::{impl#0}::new::{opaque#0})
#6 type_of(authentik[2e24]::outpost::proxy::application::{impl#0}::new::{opaque#0})
end of try_mark_green dep node stack
there was a panic while trying to force a dep node
try_mark_green dep node stack:
#0 check_well_formed(authentik[2e24]::outpost::proxy::{impl#0})
end of try_mark_green dep node stack
For more information about this error, try `rustc --explain E0599`.
error: could not compile `authentik` (bin "authentik") due to 2 previous errors
[Command exited with 101]
^Cmake: *** [Makefile:120: run-watch] Error 101

When working on goauthentik/authentik

[lqd]

This should be fixed by the next solver, right?

[dominic-r]

This should be fixed by the next solver, right?

I managed to replicate the above ^^ on latest main, which uses the next solver, if I'm not mistaken. So, I don't think so?

[lqd]

The MCVE in #159932 (comment) doesn't trigger the incremental ICE on the latest nightly, where the new solver is enabled by default. The test you've added in #162036 passes on main right now with -Znext-solver.

I managed to replicate the above ^^ on latest main

What do you mean by "latest main"?

• the backtrace you posted above doesn't seem to involve the new solver
• the backtrace is on 1.98, that's the latest stable. The new solver is enabled on nightly, where the version is 1.100.

So this issue issue looks to be about the old solver only and is already fixed by the new solver on nightly, or you're hitting a different issue than this MCVE/test (unlikely)?

[pacak]

Reproducer I posted still ICEs in the current nightly.

[pacak]

Hmmm... Interesting. It compiles with cargo +nightly test --release, but panics in the compiler test I added. I wonder.

[lqd]

Your MCVE is also missing the commands to reproduce the issue, please add them: running multiple cargo checks or cargo tests with the two edits works fine for me. But if the issue reproduces with the new solver, then it shouldn't be closed by #162036 and https://github.com/rust-lang/rust/pull/162036/changes#diff-720e926f3b91658651e1a19f1d7ee8634db5c5fc222dbd57aaa49d66c18e2a19 is different from your MCVE.

[pacak]

cargo test --release
// edit
cargo test --release

crashes stable, but not nightly.

This test fails for whatever reason.

Right on top of 45f215f

//@ revisions: rpass1 rpass2
//@ edition: 2024

struct J<I>(I);

impl<I> std::future::Future for J<I>
where
    I: IntoIterator,
{
    type Output = ();
    fn poll(
        self: std::pin::Pin<&mut Self>,
        _: &mut std::task::Context<'_>,
    ) -> std::task::Poll<Self::Output> {
        loop {}
    }
}

fn spawn<F: std::future::Future + Send>(_: F) {}

async fn bar() {
    J([std::future::ready(())].into_iter().map(async |r| r.await)).await;
}

fn main() {
    spawn(async {
        #[cfg(rpass1)]
        {
            let _ = bar().await;
        }


        #[cfg(rpass2)]
        {
            let results = bar().await;
        }
    });
}

bt.txt