rust-lang / rust-lang/rust

[ICE]: Found unstable fingerprints for evaluate_obligation(<hash>): Ok(EvaluatedToOk)

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A-incr-comp C-bug I-ICE S-needs-repro T-compiler
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Description

Hi, I don't really know how did it happen to be, probably due to incremental compilation. I can't provide a minimal example, but just maybe the backtrace will help somehow. I have 9 ice files which are almost identical, here I provide one of them.

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rustc --version --verbose:

rustc 1.97.0-nightly (ad3a598ca 2026-05-03)
binary: rustc
commit-hash: ad3a598ca4bc7c68bcbbce3e0d3be9a7618df190
commit-date: 2026-05-03
host: x86_64-unknown-linux-gnu
release: 1.97.0-nightly
LLVM version: 22.1.4
Error output
thread 'rustc' panicked at /rustc-dev/ad3a598ca4bc7c68bcbbce3e0d3be9a7618df190/compiler/rustc_middle/src/verify_ich.rs:82:9:
Found unstable fingerprints for evaluate_obligation(699fbf93707fac87-8fbe3b606f564c1e): Ok(EvaluatedToOk)
Backtrace 

thread 'rustc' panicked at /rustc-dev/ad3a598ca4bc7c68bcbbce3e0d3be9a7618df190/compiler/rustc_middle/src/verify_ich.rs:82:9:
Found unstable fingerprints for evaluate_obligation(699fbf93707fac87-8fbe3b606f564c1e): Ok(EvaluatedToOk)
stack backtrace:
   0:     0x7fc4df9ea7eb - <std[153009beb0d131ab]::backtrace::Backtrace>::create
   1:     0x7fc4df9ea735 - <std[153009beb0d131ab]::backtrace::Backtrace>::force_capture
   2:     0x7fc4de90a47d - std[153009beb0d131ab]::panicking::update_hook::<alloc[7edc5d3fecd118c3]::boxed::Box<rustc_driver_impl[ce0835dfefab141d]::install_ice_hook::{closure#1}>>::{closure#0}
   3:     0x7fc4df9fd432 - std[153009beb0d131ab]::panicking::panic_with_hook
   4:     0x7fc4df9dfd32 - std[153009beb0d131ab]::panicking::panic_handler::{closure#0}
   5:     0x7fc4df9d4269 - std[153009beb0d131ab]::sys::backtrace::__rust_end_short_backtrace::<std[153009beb0d131ab]::panicking::panic_handler::{closure#0}, !>
   6:     0x7fc4df9e179d - __rustc[a5947e614d7bb0f8]::rust_begin_unwind
   7:     0x7fc4dcaf296c - core[78df9d5a9219d9b7]::panicking::panic_fmt
   8:     0x7fc4def6cfc7 - rustc_middle[35f5a067ffa0c144]::verify_ich::incremental_verify_ich_failed
   9:     0x7fc4e02f4156 - rustc_middle[35f5a067ffa0c144]::verify_ich::incremental_verify_ich::<rustc_middle[35f5a067ffa0c144]::query::erase::ErasedData<[u8; 2usize]>>
  10:     0x7fc4e08a9f8a - rustc_query_impl[2f52a9c8c9a76d9d]::execution::try_execute_query::<rustc_middle[35f5a067ffa0c144]::query::caches::DefaultCache<rustc_type_ir[3c1cd9fa91348b82]::canonical::CanonicalQueryInput<rustc_middle[35f5a067ffa0c144]::ty::context::TyCtxt, rustc_middle[35f5a067ffa0c144]::ty::ParamEnvAnd<rustc_middle[35f5a067ffa0c144]::ty::predicate::Predicate>>, rustc_middle[35f5a067ffa0c144]::query::erase::ErasedData<[u8; 2usize]>>, true>
  11:     0x7fc4e08a8bb6 - rustc_query_impl[2f52a9c8c9a76d9d]::query_impl::evaluate_obligation::execute_query_incr::__rust_end_short_backtrace
  12:     0x7fc4e08a1c1c - <rustc_trait_selection[9b244e702b3f942b]::traits::fulfill::FulfillProcessor as rustc_data_structures[fd08730a6b0893d5]::obligation_forest::ObligationProcessor>::process_obligation
  13:     0x7fc4e0005a50 - <rustc_data_structures[fd08730a6b0893d5]::obligation_forest::ObligationForest<rustc_trait_selection[9b244e702b3f942b]::traits::fulfill::PendingPredicateObligation>>::process_obligations::<rustc_trait_selection[9b244e702b3f942b]::traits::fulfill::FulfillProcessor>
  14:     0x7fc4e03e3db9 - <rustc_hir_typeck[16f50491da5982a9]::fn_ctxt::FnCtxt>::check_expr_call
  15:     0x7fc4e041ac31 - <rustc_hir_typeck[16f50491da5982a9]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  16:     0x7fc4e0ca5128 - <rustc_hir_typeck[16f50491da5982a9]::fn_ctxt::FnCtxt>::check_expr_method_call
  17:     0x7fc4e041b693 - <rustc_hir_typeck[16f50491da5982a9]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  18:     0x7fc4e0ca2e5c - <rustc_hir_typeck[16f50491da5982a9]::fn_ctxt::FnCtxt>::check_expr_method_call
  19:     0x7fc4e041b693 - <rustc_hir_typeck[16f50491da5982a9]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  20:     0x7fc4e03f86b2 - <rustc_hir_typeck[16f50491da5982a9]::fn_ctxt::FnCtxt>::check_expr_block
  21:     0x7fc4e041b66e - <rustc_hir_typeck[16f50491da5982a9]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  22:     0x7fc4e02f601c - rustc_hir_typeck[16f50491da5982a9]::check::check_fn
  23:     0x7fc4e08f77b4 - rustc_hir_typeck[16f50491da5982a9]::typeck_with_inspect::{closure#0}
  24:     0x7fc4e08f45f4 - rustc_query_impl[2f52a9c8c9a76d9d]::query_impl::typeck_root::invoke_provider_fn::__rust_begin_short_backtrace
  25:     0x7fc4e013e5a1 - rustc_query_impl[2f52a9c8c9a76d9d]::execution::try_execute_query::<rustc_data_structures[fd08730a6b0893d5]::vec_cache::VecCache<rustc_span[722ec6ecb2814074]::def_id::LocalDefId, rustc_middle[35f5a067ffa0c144]::query::erase::ErasedData<[u8; 8usize]>, rustc_middle[35f5a067ffa0c144]::dep_graph::graph::DepNodeIndex>, true>
  26:     0x7fc4e013d832 - rustc_query_impl[2f52a9c8c9a76d9d]::query_impl::typeck_root::execute_query_incr::__rust_end_short_backtrace
  27:     0x7fc4e02fc114 - <rustc_middle[35f5a067ffa0c144]::ty::context::TyCtxt>::par_hir_body_owners::<rustc_hir_analysis[db6f5c4cf939ab6c]::check_crate::{closure#1}>::{closure#0}
  28:     0x7fc4e02fbaea - rustc_hir_analysis[db6f5c4cf939ab6c]::check_crate
  29:     0x7fc4e0f427a1 - rustc_interface[f4b432e52c4534c9]::passes::analysis
  30:     0x7fc4e14de1b2 - rustc_query_impl[2f52a9c8c9a76d9d]::execution::try_execute_query::<rustc_middle[35f5a067ffa0c144]::query::caches::SingleCache<rustc_middle[35f5a067ffa0c144]::query::erase::ErasedData<[u8; 0usize]>>, true>
  31:     0x7fc4e14ddb6a - rustc_query_impl[2f52a9c8c9a76d9d]::query_impl::analysis::execute_query_incr::__rust_end_short_backtrace
  32:     0x7fc4e116709b - rustc_interface[f4b432e52c4534c9]::interface::run_compiler::<(), rustc_driver_impl[ce0835dfefab141d]::run_compiler::{closure#0}>::{closure#1}
  33:     0x7fc4e11a18be - std[153009beb0d131ab]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[f4b432e52c4534c9]::util::run_in_thread_with_globals<rustc_interface[f4b432e52c4534c9]::util::run_in_thread_pool_with_globals<rustc_interface[f4b432e52c4534c9]::interface::run_compiler<(), rustc_driver_impl[ce0835dfefab141d]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
  34:     0x7fc4e11a1fad - <std[153009beb0d131ab]::thread::lifecycle::spawn_unchecked<rustc_interface[f4b432e52c4534c9]::util::run_in_thread_with_globals<rustc_interface[f4b432e52c4534c9]::util::run_in_thread_pool_with_globals<rustc_interface[f4b432e52c4534c9]::interface::run_compiler<(), rustc_driver_impl[ce0835dfefab141d]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core[78df9d5a9219d9b7]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  35:     0x7fc4e11a2dac - <std[153009beb0d131ab]::sys::thread::unix::Thread>::new::thread_start
  36:     0x7fc4daca597a - <unknown>
  37:     0x7fc4dad292bc - <unknown>
  38:                0x0 - <unknown>


rustc version: 1.97.0-nightly (ad3a598ca 2026-05-03)
platform: x86_64-unknown-linux-gnu

query stack during panic:
#0 [evaluate_obligation] evaluating trait selection obligation `error::AccumulatedError: core::marker::Send`
#1 [typeck_root] type-checking `routes::population::router`
#2 [analysis] running analysis passes on crate `pts_backend`
end of query stack

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First steps

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  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start at compiler/rustc_middle/src/verify_ich.rs:82 and trace the evaluate_obligation query shown in the query stack, focusing on incremental compilation. Use the reporter's supplied ICE case and nine similar files to reproduce the panic, then add a regression test demonstrating stable fingerprints and no ICE.

Written by the indexing model from the issue text.

Assessment

Tech stack
rust
Domain
compilers
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Quiet
Clarity
Needs clarification
Newbie friendliness
28/100

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