ICE should not select host obligation in old solver in intercrate mode #149703
Description
auto-reduced (treereduce-rust):
trait X {}
trait Z {
type Assoc: Y;
}
struct A<T>(T);
impl<T: const FnOnce(()) -> i32> Z for A<T> {}
impl<T> From<<A<A<T>> as Z>::Assoc> for T {}original:
trait X {}
trait Z {
type Assoc: Y;
}
struct A<T>(T);
impl<T: const FnOnce(()) -> i32> Z for A<T> {
type Assoc = T;
}
impl<T> From<<A<A<T>> as Z>::Assoc> for T {}Version information
rustc 1.93.0-nightly (66428d92b 2025-12-05)
binary: rustc
commit-hash: 66428d92bec337ed4785d695d0127276a482278c
commit-date: 2025-12-05
host: x86_64-unknown-linux-gnu
release: 1.93.0-nightly
LLVM version: 21.1.5
Possibly related line of code:
rust/compiler/rustc_trait_selection/src/traits/effects.rs
Lines 23 to 35 in 66428d9
Command:
/home/matthias/.rustup/toolchains/master/bin/rustc
Program output
error[E0405]: cannot find trait `Y` in this scope
--> /tmp/icemaker_global_tempdir.bAeSV9EYs3Nh/rustc_testrunner_tmpdir_reporting.9b7fonKIt25S/mvce.rs:4:17
|
1 | trait X {}
| ------- similarly named trait `X` defined here
...
4 | type Assoc: Y;
| ^ help: a trait with a similar name exists: `X`
error[E0658]: const trait impls are experimental
--> /tmp/icemaker_global_tempdir.bAeSV9EYs3Nh/rustc_testrunner_tmpdir_reporting.9b7fonKIt25S/mvce.rs:8:9
|
8 | impl<T: const FnOnce(()) -> i32> Z for A<T> {}
| ^^^^^
|
= note: see issue #143874 <https://github.com/rust-lang/rust/issues/143874> for more information
= help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
= note: this compiler was built on 2025-12-05; consider upgrading it if it is out of date
error[E0601]: `main` function not found in crate `mvce`
--> /tmp/icemaker_global_tempdir.bAeSV9EYs3Nh/rustc_testrunner_tmpdir_reporting.9b7fonKIt25S/mvce.rs:10:45
|
10 | impl<T> From<<A<A<T>> as Z>::Assoc> for T {}
| ^ consider adding a `main` function to `/tmp/icemaker_global_tempdir.bAeSV9EYs3Nh/rustc_testrunner_tmpdir_reporting.9b7fonKIt25S/mvce.rs`
error[E0658]: use of unstable const library feature `const_trait_impl`
--> /tmp/icemaker_global_tempdir.bAeSV9EYs3Nh/rustc_testrunner_tmpdir_reporting.9b7fonKIt25S/mvce.rs:8:15
|
8 | impl<T: const FnOnce(()) -> i32> Z for A<T> {}
| ----- ^^^^^^^^^^^^^^^^^
| |
| trait is not stable as const yet
|
= note: see issue #143874 <https://github.com/rust-lang/rust/issues/143874> for more information
= help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
= note: this compiler was built on 2025-12-05; consider upgrading it if it is out of date
error[E0046]: not all trait items implemented, missing: `Assoc`
--> /tmp/icemaker_global_tempdir.bAeSV9EYs3Nh/rustc_testrunner_tmpdir_reporting.9b7fonKIt25S/mvce.rs:8:1
|
4 | type Assoc: Y;
| ------------- `Assoc` from trait
...
8 | impl<T: const FnOnce(()) -> i32> Z for A<T> {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ missing `Assoc` in implementation
error: internal compiler error: compiler/rustc_trait_selection/src/traits/effects.rs:29:9: should not select host obligation in old solver in intercrate mode
thread 'rustc' (1929049) panicked at compiler/rustc_trait_selection/src/traits/effects.rs:29:9:
Box<dyn Any>
stack backtrace:
0: 0x7f566e26f6b3 - <<std[d1cf8494b7637499]::sys::backtrace::BacktraceLock>::print::DisplayBacktrace as core[7a5baad27c58ac9b]::fmt::Display>::fmt
1: 0x7f566e811848 - core[7a5baad27c58ac9b]::fmt::write
2: 0x7f566e285ed6 - <std[d1cf8494b7637499]::sys::stdio::unix::Stderr as std[d1cf8494b7637499]::io::Write>::write_fmt
3: 0x7f566e245e78 - std[d1cf8494b7637499]::panicking::default_hook::{closure#0}
4: 0x7f566e263583 - std[d1cf8494b7637499]::panicking::default_hook
5: 0x7f566d2cfec7 - std[d1cf8494b7637499]::panicking::update_hook::<alloc[fc8570482610e41]::boxed::Box<rustc_driver_impl[9b4b378bd639d3bd]::install_ice_hook::{closure#1}>>::{closure#0}
6: 0x7f566e263862 - std[d1cf8494b7637499]::panicking::panic_with_hook
7: 0x7f566d30bf41 - std[d1cf8494b7637499]::panicking::begin_panic::<rustc_errors[888950e5e47c8ba6]::ExplicitBug>::{closure#0}
8: 0x7f566d2fc596 - std[d1cf8494b7637499]::sys::backtrace::__rust_end_short_backtrace::<std[d1cf8494b7637499]::panicking::begin_panic<rustc_errors[888950e5e47c8ba6]::ExplicitBug>::{closure#0}, !>
9: 0x7f566d2fc1cf - std[d1cf8494b7637499]::panicking::begin_panic::<rustc_errors[888950e5e47c8ba6]::ExplicitBug>
10: 0x7f566d329641 - <rustc_errors[888950e5e47c8ba6]::diagnostic::BugAbort as rustc_errors[888950e5e47c8ba6]::diagnostic::EmissionGuarantee>::emit_producing_guarantee
11: 0x7f566d86a94c - <rustc_errors[888950e5e47c8ba6]::DiagCtxtHandle>::span_bug::<rustc_span[a0d314e698c4c838]::span_encoding::Span, alloc[fc8570482610e41]::string::String>
12: 0x7f566d88b936 - rustc_middle[35056dba64335523]::util::bug::opt_span_bug_fmt::<rustc_span[a0d314e698c4c838]::span_encoding::Span>::{closure#0}
13: 0x7f566d88bae2 - rustc_middle[35056dba64335523]::ty::context::tls::with_opt::<rustc_middle[35056dba64335523]::util::bug::opt_span_bug_fmt<rustc_span[a0d314e698c4c838]::span_encoding::Span>::{closure#0}, !>::{closure#0}
14: 0x7f566d87cdbb - rustc_middle[35056dba64335523]::ty::context::tls::with_context_opt::<rustc_middle[35056dba64335523]::ty::context::tls::with_opt<rustc_middle[35056dba64335523]::util::bug::opt_span_bug_fmt<rustc_span[a0d314e698c4c838]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
15: 0x7f566be0c638 - rustc_middle[35056dba64335523]::util::bug::span_bug_fmt::<rustc_span[a0d314e698c4c838]::span_encoding::Span>
16: 0x7f566ed9b7ee - rustc_trait_selection[bfbaae654e06ec63]::traits::effects::evaluate_host_effect_obligation
17: 0x7f566f06e387 - <rustc_trait_selection[bfbaae654e06ec63]::traits::fulfill::FulfillProcessor as rustc_data_structures[adb2697dbf3e0adc]::obligation_forest::ObligationProcessor>::process_obligation
18: 0x7f566e804764 - <rustc_data_structures[adb2697dbf3e0adc]::obligation_forest::ObligationForest<rustc_trait_selection[bfbaae654e06ec63]::traits::fulfill::PendingPredicateObligation>>::process_obligations::<rustc_trait_selection[bfbaae654e06ec63]::traits::fulfill::FulfillProcessor>
19: 0x7f566f181aba - <rustc_trait_selection[bfbaae654e06ec63]::traits::fulfill::FulfillmentContext<rustc_infer[4ccc06062613e9a]::traits::engine::ScrubbedTraitError> as rustc_infer[4ccc06062613e9a]::traits::engine::TraitEngine<rustc_infer[4ccc06062613e9a]::traits::engine::ScrubbedTraitError>>::try_evaluate_obligations
20: 0x7f566ee1f4c1 - <rustc_next_trait_solver[c4031e005c555ac1]::coherence::OrphanChecker<rustc_infer[4ccc06062613e9a]::infer::InferCtxt, rustc_middle[35056dba64335523]::ty::context::TyCtxt, rustc_hir_analysis[c90d90e42cbb1186]::coherence::orphan::orphan_check::{closure#0}::{closure#0}> as rustc_type_ir[45ed6e391ddc621c]::visit::TypeVisitor<rustc_middle[35056dba64335523]::ty::context::TyCtxt>>::visit_ty
21: 0x7f566d40e33f - <rustc_type_ir[45ed6e391ddc621c]::predicate::TraitRef<rustc_middle[35056dba64335523]::ty::context::TyCtxt> as rustc_type_ir[45ed6e391ddc621c]::visit::TypeVisitable<rustc_middle[35056dba64335523]::ty::context::TyCtxt>>::visit_with::<rustc_next_trait_solver[c4031e005c555ac1]::coherence::OrphanChecker<rustc_infer[4ccc06062613e9a]::infer::InferCtxt, rustc_middle[35056dba64335523]::ty::context::TyCtxt, rustc_hir_analysis[c90d90e42cbb1186]::coherence::orphan::orphan_check::{closure#0}::{closure#0}>>
22: 0x7f566ee1f101 - rustc_hir_analysis[c90d90e42cbb1186]::coherence::orphan::orphan_check
23: 0x7f566ee1f727 - rustc_hir_analysis[c90d90e42cbb1186]::coherence::orphan::orphan_check_impl
24: 0x7f566ee1f60d - rustc_query_impl[ac86e4dc6825f939]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[ac86e4dc6825f939]::query_impl::orphan_check_impl::dynamic_query::{closure#2}::{closure#0}, rustc_middle[35056dba64335523]::query::erase::Erased<[u8; 1usize]>>
25: 0x7f566ef865ed - rustc_query_system[59d0c891baa5ac40]::query::plumbing::try_execute_query::<rustc_query_impl[ac86e4dc6825f939]::DynamicConfig<rustc_data_structures[adb2697dbf3e0adc]::vec_cache::VecCache<rustc_span[a0d314e698c4c838]::def_id::LocalDefId, rustc_middle[35056dba64335523]::query::erase::Erased<[u8; 1usize]>, rustc_query_system[59d0c891baa5ac40]::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl[ac86e4dc6825f939]::plumbing::QueryCtxt, false>
26: 0x7f566ef85f8f - rustc_query_impl[ac86e4dc6825f939]::query_impl::orphan_check_impl::get_query_non_incr::__rust_end_short_backtrace
27: 0x7f566e952b51 - rustc_hir_analysis[c90d90e42cbb1186]::coherence::coherent_trait
28: 0x7f566e952695 - rustc_query_impl[ac86e4dc6825f939]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[ac86e4dc6825f939]::query_impl::coherent_trait::dynamic_query::{closure#2}::{closure#0}, rustc_middle[35056dba64335523]::query::erase::Erased<[u8; 1usize]>>
29: 0x7f566ed77be3 - rustc_query_system[59d0c891baa5ac40]::query::plumbing::try_execute_query::<rustc_query_impl[ac86e4dc6825f939]::DynamicConfig<rustc_query_system[59d0c891baa5ac40]::query::caches::DefIdCache<rustc_middle[35056dba64335523]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[ac86e4dc6825f939]::plumbing::QueryCtxt, false>
30: 0x7f566ed76ca4 - rustc_query_impl[ac86e4dc6825f939]::query_impl::coherent_trait::get_query_non_incr::__rust_end_short_backtrace
31: 0x7f566ef8bbd5 - rustc_hir_analysis[c90d90e42cbb1186]::check::check::check_item_type
32: 0x7f566ef86ff6 - rustc_hir_analysis[c90d90e42cbb1186]::check::wfcheck::check_well_formed
33: 0x7f566ef86fd7 - rustc_query_impl[ac86e4dc6825f939]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[ac86e4dc6825f939]::query_impl::check_well_formed::dynamic_query::{closure#2}::{closure#0}, rustc_middle[35056dba64335523]::query::erase::Erased<[u8; 1usize]>>
34: 0x7f566ef8684d - rustc_query_system[59d0c891baa5ac40]::query::plumbing::try_execute_query::<rustc_query_impl[ac86e4dc6825f939]::DynamicConfig<rustc_data_structures[adb2697dbf3e0adc]::vec_cache::VecCache<rustc_span[a0d314e698c4c838]::def_id::LocalDefId, rustc_middle[35056dba64335523]::query::erase::Erased<[u8; 1usize]>, rustc_query_system[59d0c891baa5ac40]::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl[ac86e4dc6825f939]::plumbing::QueryCtxt, false>
35: 0x7f566ef86356 - rustc_query_impl[ac86e4dc6825f939]::query_impl::check_well_formed::get_query_non_incr::__rust_end_short_backtrace
36: 0x7f566ef83af0 - rustc_hir_analysis[c90d90e42cbb1186]::check::wfcheck::check_type_wf
37: 0x7f566ef839e1 - rustc_query_impl[ac86e4dc6825f939]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[ac86e4dc6825f939]::query_impl::check_type_wf::dynamic_query::{closure#2}::{closure#0}, rustc_middle[35056dba64335523]::query::erase::Erased<[u8; 1usize]>>
38: 0x7f566f961348 - rustc_query_system[59d0c891baa5ac40]::query::plumbing::try_execute_query::<rustc_query_impl[ac86e4dc6825f939]::DynamicConfig<rustc_query_system[59d0c891baa5ac40]::query::caches::SingleCache<rustc_middle[35056dba64335523]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[ac86e4dc6825f939]::plumbing::QueryCtxt, false>
39: 0x7f566f96110e - rustc_query_impl[ac86e4dc6825f939]::query_impl::check_type_wf::get_query_non_incr::__rust_end_short_backtrace
40: 0x7f566f3eb4ba - rustc_hir_analysis[c90d90e42cbb1186]::check_crate
41: 0x7f566ea96e95 - rustc_interface[a570f551ea6bf79f]::passes::analysis
42: 0x7f566ea96b5b - rustc_query_impl[ac86e4dc6825f939]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[ac86e4dc6825f939]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[35056dba64335523]::query::erase::Erased<[u8; 0usize]>>
43: 0x7f566f964388 - rustc_query_system[59d0c891baa5ac40]::query::plumbing::try_execute_query::<rustc_query_impl[ac86e4dc6825f939]::DynamicConfig<rustc_query_system[59d0c891baa5ac40]::query::caches::SingleCache<rustc_middle[35056dba64335523]::query::erase::Erased<[u8; 0usize]>>, false, false, false>, rustc_query_impl[ac86e4dc6825f939]::plumbing::QueryCtxt, false>
44: 0x7f566f963fbe - rustc_query_impl[ac86e4dc6825f939]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
45: 0x7f566faf6410 - <rustc_interface[a570f551ea6bf79f]::passes::create_and_enter_global_ctxt<core[7a5baad27c58ac9b]::option::Option<rustc_interface[a570f551ea6bf79f]::queries::Linker>, rustc_driver_impl[9b4b378bd639d3bd]::run_compiler::{closure#0}::{closure#2}>::{closure#2} as core[7a5baad27c58ac9b]::ops::function::FnOnce<(&rustc_session[61d9c53fe18acc9a]::session::Session, rustc_middle[35056dba64335523]::ty::context::CurrentGcx, alloc[fc8570482610e41]::sync::Arc<rustc_data_structures[adb2697dbf3e0adc]::jobserver::Proxy>, &std[d1cf8494b7637499]::sync::once_lock::OnceLock<rustc_middle[35056dba64335523]::ty::context::GlobalCtxt>, &rustc_data_structures[adb2697dbf3e0adc]::sync::worker_local::WorkerLocal<rustc_middle[35056dba64335523]::arena::Arena>, &rustc_data_structures[adb2697dbf3e0adc]::sync::worker_local::WorkerLocal<rustc_hir[670b2116001876c4]::Arena>, rustc_driver_impl[9b4b378bd639d3bd]::run_compiler::{closure#0}::{closure#2})>>::call_once::{shim:vtable#0}
46: 0x7f566f9b8c85 - rustc_interface[a570f551ea6bf79f]::interface::run_compiler::<(), rustc_driver_impl[9b4b378bd639d3bd]::run_compiler::{closure#0}>::{closure#1}
47: 0x7f566f90e1d6 - std[d1cf8494b7637499]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[a570f551ea6bf79f]::util::run_in_thread_with_globals<rustc_interface[a570f551ea6bf79f]::util::run_in_thread_pool_with_globals<rustc_interface[a570f551ea6bf79f]::interface::run_compiler<(), rustc_driver_impl[9b4b378bd639d3bd]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
48: 0x7f566f90dfa9 - <std[d1cf8494b7637499]::thread::lifecycle::spawn_unchecked<rustc_interface[a570f551ea6bf79f]::util::run_in_thread_with_globals<rustc_interface[a570f551ea6bf79f]::util::run_in_thread_pool_with_globals<rustc_interface[a570f551ea6bf79f]::interface::run_compiler<(), rustc_driver_impl[9b4b378bd639d3bd]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core[7a5baad27c58ac9b]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
49: 0x7f566f90c3f8 - <std[d1cf8494b7637499]::sys::thread::unix::Thread>::new::thread_start
50: 0x7f56694969cb - <unknown>
51: 0x7f566951aa0c - <unknown>
52: 0x0 - <unknown>
note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md
note: please make sure that you have updated to the latest nightly
note: rustc 1.93.0-nightly (66428d92b 2025-12-05) running on x86_64-unknown-linux-gnu
query stack during panic:
#0 [orphan_check_impl] checking whether impl `<impl at /tmp/icemaker_global_tempdir.bAeSV9EYs3Nh/rustc_testrunner_tmpdir_reporting.9b7fonKIt25S/mvce.rs:10:1: 10:42>` follows the orphan rules
#1 [coherent_trait] coherence checking all impls of trait `core::convert::From`
#2 [check_well_formed] checking that `<impl at /tmp/icemaker_global_tempdir.bAeSV9EYs3Nh/rustc_testrunner_tmpdir_reporting.9b7fonKIt25S/mvce.rs:10:1: 10:42>` is well-formed
#3 [check_type_wf] checking that types are well-formed
#4 [analysis] running analysis passes on crate `mvce`
end of query stack
error: aborting due to 6 previous errors
Some errors have detailed explanations: E0046, E0405, E0601, E0658.
For more information about an error, try `rustc --explain E0046`.