ICE: assertion failed: !ty.has_non_region_infer()

[matthiaskrgr]

snippet, original probably from tests/ui/const-generics/type-dependent/issue-70507.rs

#![feature(min_specialization)]

impl<'a, T: std::fmt::Debug, const N: usize> Iterator for ConstChunksExact<'a, T, { N }> {
    fn next(&mut self) -> Option<Self::Item> {}
}

struct ConstChunksExact<'a, T: '_, const assert: usize> {}

impl<'a, T: std::fmt::Debug, const N: usize> Iterator for ConstChunksExact<'a, T, {}> {
    type Item = &'a [T; N];
}

Version information

rustc 1.79.0-nightly (ecdea9e94 2024-03-17)
binary: rustc
commit-hash: ecdea9e9438cdb8cf707e7f60e066eda02344d05
commit-date: 2024-03-17
host: x86_64-unknown-linux-gnu
release: 1.79.0-nightly
LLVM version: 18.1.2

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

Program output

error[E0637]: `'_` cannot be used here
 --> /tmp/icemaker_global_tempdir.NwJkWeuZqOxD/rustc_testrunner_tmpdir_reporting.DGCv6r40KmDi/mvce.rs:7:32
  |
7 | struct ConstChunksExact<'a, T: '_, const assert: usize> {}
  |                                ^^ `'_` is a reserved lifetime name

error[E0601]: `main` function not found in crate `mvce`
  --> /tmp/icemaker_global_tempdir.NwJkWeuZqOxD/rustc_testrunner_tmpdir_reporting.DGCv6r40KmDi/mvce.rs:11:2
   |
11 | }
   |  ^ consider adding a `main` function to `/tmp/icemaker_global_tempdir.NwJkWeuZqOxD/rustc_testrunner_tmpdir_reporting.DGCv6r40KmDi/mvce.rs`

error[E0308]: mismatched types
 --> /tmp/icemaker_global_tempdir.NwJkWeuZqOxD/rustc_testrunner_tmpdir_reporting.DGCv6r40KmDi/mvce.rs:9:83
  |
9 | impl<'a, T: std::fmt::Debug, const N: usize> Iterator for ConstChunksExact<'a, T, {}> {
  |                                                                                   ^^ expected `usize`, found `()`

thread 'rustc' panicked at compiler/rustc_trait_selection/src/traits/outlives_bounds.rs:51:5:
assertion failed: !ty.has_non_region_infer()
stack backtrace:
   0:     0x7f8b45b8c912 - std::backtrace_rs::backtrace::libunwind::trace::h130a839c96311127
                               at /rustc/ecdea9e9438cdb8cf707e7f60e066eda02344d05/library/std/src/../../backtrace/src/backtrace/libunwind.rs:105:5
   1:     0x7f8b45b8c912 - std::backtrace_rs::backtrace::trace_unsynchronized::h5053166127c32fca
                               at /rustc/ecdea9e9438cdb8cf707e7f60e066eda02344d05/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7f8b45b8c912 - std::sys_common::backtrace::_print_fmt::hc8bfe34d9b6ab8fa
                               at /rustc/ecdea9e9438cdb8cf707e7f60e066eda02344d05/library/std/src/sys_common/backtrace.rs:68:5
   3:     0x7f8b45b8c912 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hf5178e0e8c2a3754
                               at /rustc/ecdea9e9438cdb8cf707e7f60e066eda02344d05/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x7f8b45bddc8c - core::fmt::rt::Argument::fmt::h0a056d227bbd784c
                               at /rustc/ecdea9e9438cdb8cf707e7f60e066eda02344d05/library/core/src/fmt/rt.rs:142:9
   5:     0x7f8b45bddc8c - core::fmt::write::h10db7fef763d7bc1
                               at /rustc/ecdea9e9438cdb8cf707e7f60e066eda02344d05/library/core/src/fmt/mod.rs:1153:17
   6:     0x7f8b45b8180f - std::io::Write::write_fmt::hae2c866742ac8216
                               at /rustc/ecdea9e9438cdb8cf707e7f60e066eda02344d05/library/std/src/io/mod.rs:1843:15
   7:     0x7f8b45b8c6e4 - std::sys_common::backtrace::_print::h5b25d695d3c3668b
                               at /rustc/ecdea9e9438cdb8cf707e7f60e066eda02344d05/library/std/src/sys_common/backtrace.rs:47:5
   8:     0x7f8b45b8c6e4 - std::sys_common::backtrace::print::h734c64740bca27d9
                               at /rustc/ecdea9e9438cdb8cf707e7f60e066eda02344d05/library/std/src/sys_common/backtrace.rs:34:9
   9:     0x7f8b45b8f3eb - std::panicking::default_hook::{{closure}}::hee6d4abdb3c0f483
  10:     0x7f8b45b8f143 - std::panicking::default_hook::h6fd6c192a391bb75
                               at /rustc/ecdea9e9438cdb8cf707e7f60e066eda02344d05/library/std/src/panicking.rs:292:9
  11:     0x7f8b48bb545f - std[1edb51698615b6b2]::panicking::update_hook::<alloc[e67a01ca5641d9fc]::boxed::Box<rustc_driver_impl[e0ef1a8995aede8b]::install_ice_hook::{closure#0}>>::{closure#0}
  12:     0x7f8b45b8fb50 - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::h3d34b5ca386d93df
                               at /rustc/ecdea9e9438cdb8cf707e7f60e066eda02344d05/library/alloc/src/boxed.rs:2034:9
  13:     0x7f8b45b8fb50 - std::panicking::rust_panic_with_hook::ha06f2d1f1e60cb61
                               at /rustc/ecdea9e9438cdb8cf707e7f60e066eda02344d05/library/std/src/panicking.rs:783:13
  14:     0x7f8b45b8f859 - std::panicking::begin_panic_handler::{{closure}}::h8bd340824b2f16fb
                               at /rustc/ecdea9e9438cdb8cf707e7f60e066eda02344d05/library/std/src/panicking.rs:649:13
  15:     0x7f8b45b8cde6 - std::sys_common::backtrace::__rust_end_short_backtrace::h73dc69ff952ce613
                               at /rustc/ecdea9e9438cdb8cf707e7f60e066eda02344d05/library/std/src/sys_common/backtrace.rs:171:18
  16:     0x7f8b45b8f5c4 - rust_begin_unwind
                               at /rustc/ecdea9e9438cdb8cf707e7f60e066eda02344d05/library/std/src/panicking.rs:645:5
  17:     0x7f8b45bda1a5 - core::panicking::panic_fmt::heaebb21c3402ed66
                               at /rustc/ecdea9e9438cdb8cf707e7f60e066eda02344d05/library/core/src/panicking.rs:72:14
  18:     0x7f8b45bda263 - core::panicking::panic::he4503a1f8c8c6482
                               at /rustc/ecdea9e9438cdb8cf707e7f60e066eda02344d05/library/core/src/panicking.rs:145:5
  19:     0x7f8b4788b3ad - rustc_trait_selection[7f61bd169b63885]::traits::outlives_bounds::implied_outlives_bounds
  20:     0x7f8b4a4c1436 - <rustc_infer[d3187ed693eaf61e]::infer::outlives::env::OutlivesEnvironment>::with_bounds::<core[b12cd9a0ca34f197]::iter::adapters::flatten::FlatMap<indexmap[d807711f4009a88]::set::iter::Iter<rustc_middle[7b6cdb9727477273]::ty::Ty>, alloc[e67a01ca5641d9fc]::vec::Vec<rustc_middle[7b6cdb9727477273]::traits::query::OutlivesBound>, <rustc_infer[d3187ed693eaf61e]::infer::InferCtxt as rustc_trait_selection[7f61bd169b63885]::traits::outlives_bounds::InferCtxtExt>::implied_bounds_tys::{closure#0}>>
  21:     0x7f8b4a4a0fe0 - rustc_hir_analysis[3992a0a0dd7933ad]::check::check::check_item_type
  22:     0x7f8b4a4c9adc - rustc_hir_analysis[3992a0a0dd7933ad]::check::wfcheck::check_well_formed
  23:     0x7f8b4a4c85c7 - rustc_query_impl[199a7318a0a2d0ea]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[199a7318a0a2d0ea]::query_impl::check_well_formed::dynamic_query::{closure#2}::{closure#0}, rustc_middle[7b6cdb9727477273]::query::erase::Erased<[u8; 1usize]>>
  24:     0x7f8b4a4c7d40 - rustc_query_system[5343cac5ae2d7d0f]::query::plumbing::try_execute_query::<rustc_query_impl[199a7318a0a2d0ea]::DynamicConfig<rustc_query_system[5343cac5ae2d7d0f]::query::caches::VecCache<rustc_hir[a79073bc83b4044]::hir_id::OwnerId, rustc_middle[7b6cdb9727477273]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[199a7318a0a2d0ea]::plumbing::QueryCtxt, false>
  25:     0x7f8b4a4c7abf - rustc_query_impl[199a7318a0a2d0ea]::query_impl::check_well_formed::get_query_non_incr::__rust_end_short_backtrace
  26:     0x7f8b4a4c59fa - rustc_hir_analysis[3992a0a0dd7933ad]::check::wfcheck::check_mod_type_wf
  27:     0x7f8b4a4c5821 - rustc_query_impl[199a7318a0a2d0ea]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[199a7318a0a2d0ea]::query_impl::check_mod_type_wf::dynamic_query::{closure#2}::{closure#0}, rustc_middle[7b6cdb9727477273]::query::erase::Erased<[u8; 1usize]>>
  28:     0x7f8b4a8936f0 - rustc_query_system[5343cac5ae2d7d0f]::query::plumbing::try_execute_query::<rustc_query_impl[199a7318a0a2d0ea]::DynamicConfig<rustc_query_system[5343cac5ae2d7d0f]::query::caches::DefaultCache<rustc_span[1fcd8257a8e9ae58]::def_id::LocalModDefId, rustc_middle[7b6cdb9727477273]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[199a7318a0a2d0ea]::plumbing::QueryCtxt, false>
  29:     0x7f8b4a89349b - rustc_query_impl[199a7318a0a2d0ea]::query_impl::check_mod_type_wf::get_query_non_incr::__rust_end_short_backtrace
  30:     0x7f8b4a16ef8b - rustc_hir_analysis[3992a0a0dd7933ad]::check_crate
  31:     0x7f8b4a2a492a - rustc_interface[f8af93c899996b27]::passes::analysis
  32:     0x7f8b4a2a4499 - rustc_query_impl[199a7318a0a2d0ea]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[199a7318a0a2d0ea]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[7b6cdb9727477273]::query::erase::Erased<[u8; 1usize]>>
  33:     0x7f8b4ab8c4a5 - rustc_query_system[5343cac5ae2d7d0f]::query::plumbing::try_execute_query::<rustc_query_impl[199a7318a0a2d0ea]::DynamicConfig<rustc_query_system[5343cac5ae2d7d0f]::query::caches::SingleCache<rustc_middle[7b6cdb9727477273]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[199a7318a0a2d0ea]::plumbing::QueryCtxt, false>
  34:     0x7f8b4ab8c209 - rustc_query_impl[199a7318a0a2d0ea]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  35:     0x7f8b4aa67fc4 - rustc_interface[f8af93c899996b27]::interface::run_compiler::<core[b12cd9a0ca34f197]::result::Result<(), rustc_span[1fcd8257a8e9ae58]::ErrorGuaranteed>, rustc_driver_impl[e0ef1a8995aede8b]::run_compiler::{closure#0}>::{closure#0}
  36:     0x7f8b4ab63a45 - std[1edb51698615b6b2]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[f8af93c899996b27]::util::run_in_thread_with_globals<rustc_interface[f8af93c899996b27]::util::run_in_thread_pool_with_globals<rustc_interface[f8af93c899996b27]::interface::run_compiler<core[b12cd9a0ca34f197]::result::Result<(), rustc_span[1fcd8257a8e9ae58]::ErrorGuaranteed>, rustc_driver_impl[e0ef1a8995aede8b]::run_compiler::{closure#0}>::{closure#0}, core[b12cd9a0ca34f197]::result::Result<(), rustc_span[1fcd8257a8e9ae58]::ErrorGuaranteed>>::{closure#0}, core[b12cd9a0ca34f197]::result::Result<(), rustc_span[1fcd8257a8e9ae58]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[b12cd9a0ca34f197]::result::Result<(), rustc_span[1fcd8257a8e9ae58]::ErrorGuaranteed>>
  37:     0x7f8b4ab63872 - <<std[1edb51698615b6b2]::thread::Builder>::spawn_unchecked_<rustc_interface[f8af93c899996b27]::util::run_in_thread_with_globals<rustc_interface[f8af93c899996b27]::util::run_in_thread_pool_with_globals<rustc_interface[f8af93c899996b27]::interface::run_compiler<core[b12cd9a0ca34f197]::result::Result<(), rustc_span[1fcd8257a8e9ae58]::ErrorGuaranteed>, rustc_driver_impl[e0ef1a8995aede8b]::run_compiler::{closure#0}>::{closure#0}, core[b12cd9a0ca34f197]::result::Result<(), rustc_span[1fcd8257a8e9ae58]::ErrorGuaranteed>>::{closure#0}, core[b12cd9a0ca34f197]::result::Result<(), rustc_span[1fcd8257a8e9ae58]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[b12cd9a0ca34f197]::result::Result<(), rustc_span[1fcd8257a8e9ae58]::ErrorGuaranteed>>::{closure#1} as core[b12cd9a0ca34f197]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  38:     0x7f8b45b991e5 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h1668ba6e00dd332a
                               at /rustc/ecdea9e9438cdb8cf707e7f60e066eda02344d05/library/alloc/src/boxed.rs:2020:9
  39:     0x7f8b45b991e5 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h19f13da360e1925b
                               at /rustc/ecdea9e9438cdb8cf707e7f60e066eda02344d05/library/alloc/src/boxed.rs:2020:9
  40:     0x7f8b45b991e5 - std::sys::pal::unix::thread::Thread::new::thread_start::h3bd6e605cc65dc69
                               at /rustc/ecdea9e9438cdb8cf707e7f60e066eda02344d05/library/std/src/sys/pal/unix/thread.rs:108:17
  41:     0x7f8b4598155a - <unknown>
  42:     0x7f8b459fea3c - <unknown>
  43:                0x0 - <unknown>

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

note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md

note: rustc 1.79.0-nightly (ecdea9e94 2024-03-17) running on x86_64-unknown-linux-gnu

query stack during panic:
#0 [check_well_formed] checking that `<impl at /tmp/icemaker_global_tempdir.NwJkWeuZqOxD/rustc_testrunner_tmpdir_reporting.DGCv6r40KmDi/mvce.rs:3:1: 3:89>` is well-formed
#1 [check_mod_type_wf] checking that types are well-formed in top-level module
#2 [analysis] running analysis passes on this crate
end of query stack
error[E0392]: lifetime parameter `'a` is never used
 --> /tmp/icemaker_global_tempdir.NwJkWeuZqOxD/rustc_testrunner_tmpdir_reporting.DGCv6r40KmDi/mvce.rs:7:25
  |
7 | struct ConstChunksExact<'a, T: '_, const assert: usize> {}
  |                         ^^ unused lifetime parameter
  |
  = help: consider removing `'a`, referring to it in a field, or using a marker such as `PhantomData`

error[E0392]: type parameter `T` is never used
 --> /tmp/icemaker_global_tempdir.NwJkWeuZqOxD/rustc_testrunner_tmpdir_reporting.DGCv6r40KmDi/mvce.rs:7:29
  |
7 | struct ConstChunksExact<'a, T: '_, const assert: usize> {}
  |                             ^ unused type parameter
  |
  = help: consider removing `T`, referring to it in a field, or using a marker such as `PhantomData`

error[E0207]: the const parameter `N` is not constrained by the impl trait, self type, or predicates
 --> /tmp/icemaker_global_tempdir.NwJkWeuZqOxD/rustc_testrunner_tmpdir_reporting.DGCv6r40KmDi/mvce.rs:9:30
  |
9 | impl<'a, T: std::fmt::Debug, const N: usize> Iterator for ConstChunksExact<'a, T, {}> {
  |                              ^^^^^^^^^^^^^^ unconstrained const parameter
  |
  = note: expressions using a const parameter must map each value to a distinct output value
  = note: proving the result of expressions other than the parameter are unique is not supported

error: aborting due to 6 previous errors

Some errors have detailed explanations: E0207, E0308, E0392, E0601, E0637.
For more information about an error, try `rustc --explain E0207`.

[matthiaskrgr]

bisects to #121154 cc @oli-obk

[BoxyUwU]

Same cause as #123141

[ajwock]

I'm interested in working on this. I'm preparing a PR for this fix.

[ajwock]

I misspoke, I'm not actually working on this one right now. I commented under the wrong issue, but since I'm trying to help fix specialization ICE I can take a look once I'm done with the other one.

[Naserume]

It looks like the code above doesn't reproduce ice since late May, so I'm leaving another code with same ICE message but without #![feature(min_specialization)].

struct Bar;

trait Trait: Sized {
    type Assoc;
}

impl Trait for Bar { }

impl Trait for <Bar as Trait>::Assoc {
    fn bar() -> impl Sized {
        loop {}
    }
}

fn main() {}

Meta
rustc --version --verbose:

rustc 1.81.0-nightly (bcf94dec5 2024-06-23)
binary: rustc
commit-hash: bcf94dec5ba6838e435902120c0384c360126a26
commit-date: 2024-06-23
host: x86_64-apple-darwin
release: 1.81.0-nightly
LLVM version: 18.1.7

Output

error[E0407]: method `bar` is not a member of trait `Trait`
  --> ./BC86F.rs:10:5
   |
10 | /     fn bar() -> impl Sized {
11 | |         loop {}
12 | |     }
   | |_____^ not a member of trait `Trait`

error[E0275]: overflow evaluating the requirement `Bar: Trait`
  |
  = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`BC86F`)

thread 'rustc' panicked at compiler/rustc_trait_selection/src/traits/outlives_bounds.rs:53:5:
assertion failed: !ty.has_non_region_infer()
stack backtrace:
   0:        0x1028e6b43 - <std::sys::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::he71f7af0ddafc64d
   1:        0x10293225b - core::fmt::write::h30d0e266faff29b6
   2:        0x1028dcace - std::io::Write::write_fmt::he666ca78eb4b8406
   3:        0x1028e6931 - std::sys::backtrace::print::h22721f9ab9a2749a
   4:        0x1028e9709 - std::panicking::default_hook::{{closure}}::h145e29ed875d8021
   5:        0x1028e948a - std::panicking::default_hook::h5d437c7e6bf0e3b5
   6:        0x10bb8147c - std[8efa578c02603ef9]::panicking::update_hook::<alloc[135510a28be92df]::boxed::Box<rustc_driver_impl[63f2171535a6fe49]::install_ice_hook::{closure#0}>>::{closure#0}
   7:        0x1028ea326 - std::panicking::rust_panic_with_hook::h6889093a56e48d04
   8:        0x1028e9b92 - std::panicking::begin_panic_handler::{{closure}}::hedafaff529964e0a
   9:        0x1028e7019 - std::sys::backtrace::__rust_end_short_backtrace::h15452907bf21f649
  10:        0x1028e989c - _rust_begin_unwind
  11:        0x10294d4aa - core::panicking::panic_fmt::hd76eb95c9d9ba8b3
  12:        0x10294d554 - core::panicking::panic::hb329c30fe2728c0f
  13:        0x10d86b18f - rustc_trait_selection[2bb3b73d2222b57e]::traits::outlives_bounds::implied_outlives_bounds
  14:        0x10bd69fe6 - <rustc_infer[48e5f050b52d2ea4]::infer::outlives::env::OutlivesEnvironment>::with_bounds::<core[9412a59d758dca42]::iter::adapters::flatten::FlatMap<indexmap[7c6524d62d8dc6cd]::set::iter::Iter<rustc_middle[4384e439927f71dd]::ty::Ty>, alloc[135510a28be92df]::vec::Vec<rustc_middle[4384e439927f71dd]::traits::query::OutlivesBound>, <rustc_infer[48e5f050b52d2ea4]::infer::InferCtxt as rustc_trait_selection[2bb3b73d2222b57e]::traits::outlives_bounds::InferCtxtExt>::implied_bounds_tys::{closure#0}>>
  15:        0x10be836d4 - rustc_hir_analysis[8e62bc6471a04889]::check::check::check_item_type
  16:        0x10beb64ae - rustc_hir_analysis[8e62bc6471a04889]::check::wfcheck::check_well_formed
  17:        0x10d21e86c - rustc_query_impl[a24e9023943e74ab]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[a24e9023943e74ab]::query_impl::check_well_formed::dynamic_query::{closure#2}::{closure#0}, rustc_middle[4384e439927f71dd]::query::erase::Erased<[u8; 1usize]>>
  18:        0x10d09701f - rustc_query_system[30bd0146b5104221]::query::plumbing::try_execute_query::<rustc_query_impl[a24e9023943e74ab]::DynamicConfig<rustc_query_system[30bd0146b5104221]::query::caches::VecCache<rustc_hir[ae2456c39d7f6170]::hir_id::OwnerId, rustc_middle[4384e439927f71dd]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[a24e9023943e74ab]::plumbing::QueryCtxt, false>
  19:        0x10d268280 - rustc_query_impl[a24e9023943e74ab]::query_impl::check_well_formed::get_query_non_incr::__rust_end_short_backtrace
  20:        0x10bdacba2 - rustc_middle[4384e439927f71dd]::query::plumbing::query_ensure_error_guaranteed::<rustc_query_system[30bd0146b5104221]::query::caches::VecCache<rustc_hir[ae2456c39d7f6170]::hir_id::OwnerId, rustc_middle[4384e439927f71dd]::query::erase::Erased<[u8; 1usize]>>, ()>
  21:        0x10bec4de1 - rustc_hir_analysis[8e62bc6471a04889]::check::wfcheck::check_mod_type_wf
  22:        0x10d21e83c - rustc_query_impl[a24e9023943e74ab]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[a24e9023943e74ab]::query_impl::check_mod_type_wf::dynamic_query::{closure#2}::{closure#0}, rustc_middle[4384e439927f71dd]::query::erase::Erased<[u8; 1usize]>>
  23:        0x10d04db79 - rustc_query_system[30bd0146b5104221]::query::plumbing::try_execute_query::<rustc_query_impl[a24e9023943e74ab]::DynamicConfig<rustc_query_system[30bd0146b5104221]::query::caches::DefaultCache<rustc_span[aed5394308446158]::def_id::LocalModDefId, rustc_middle[4384e439927f71dd]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[a24e9023943e74ab]::plumbing::QueryCtxt, false>
  24:        0x10d244ed0 - rustc_query_impl[a24e9023943e74ab]::query_impl::check_mod_type_wf::get_query_non_incr::__rust_end_short_backtrace
  25:        0x10bf4024c - rustc_hir_analysis[8e62bc6471a04889]::check_crate
  26:        0x10c4da6cb - rustc_interface[73216d77aad0c3a5]::passes::run_required_analyses
  27:        0x10c4dccb3 - rustc_interface[73216d77aad0c3a5]::passes::analysis
  28:        0x10d222dec - rustc_query_impl[a24e9023943e74ab]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[a24e9023943e74ab]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[4384e439927f71dd]::query::erase::Erased<[u8; 1usize]>>
  29:        0x10d00249e - rustc_query_system[30bd0146b5104221]::query::plumbing::try_execute_query::<rustc_query_impl[a24e9023943e74ab]::DynamicConfig<rustc_query_system[30bd0146b5104221]::query::caches::SingleCache<rustc_middle[4384e439927f71dd]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[a24e9023943e74ab]::plumbing::QueryCtxt, false>
  30:        0x10d22d307 - rustc_query_impl[a24e9023943e74ab]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  31:        0x10bb258d7 - <rustc_interface[73216d77aad0c3a5]::queries::QueryResult<&rustc_middle[4384e439927f71dd]::ty::context::GlobalCtxt>>::enter::<core[9412a59d758dca42]::result::Result<(), rustc_span[aed5394308446158]::ErrorGuaranteed>, rustc_driver_impl[63f2171535a6fe49]::run_compiler::{closure#0}::{closure#1}::{closure#3}>
  32:        0x10bb7fc94 - rustc_interface[73216d77aad0c3a5]::interface::run_compiler::<core[9412a59d758dca42]::result::Result<(), rustc_span[aed5394308446158]::ErrorGuaranteed>, rustc_driver_impl[63f2171535a6fe49]::run_compiler::{closure#0}>::{closure#1}
  33:        0x10bb6ec91 - std[8efa578c02603ef9]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[73216d77aad0c3a5]::util::run_in_thread_with_globals<rustc_interface[73216d77aad0c3a5]::util::run_in_thread_pool_with_globals<rustc_interface[73216d77aad0c3a5]::interface::run_compiler<core[9412a59d758dca42]::result::Result<(), rustc_span[aed5394308446158]::ErrorGuaranteed>, rustc_driver_impl[63f2171535a6fe49]::run_compiler::{closure#0}>::{closure#1}, core[9412a59d758dca42]::result::Result<(), rustc_span[aed5394308446158]::ErrorGuaranteed>>::{closure#0}, core[9412a59d758dca42]::result::Result<(), rustc_span[aed5394308446158]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[9412a59d758dca42]::result::Result<(), rustc_span[aed5394308446158]::ErrorGuaranteed>>
  34:        0x10bb8a3a6 - <<std[8efa578c02603ef9]::thread::Builder>::spawn_unchecked_<rustc_interface[73216d77aad0c3a5]::util::run_in_thread_with_globals<rustc_interface[73216d77aad0c3a5]::util::run_in_thread_pool_with_globals<rustc_interface[73216d77aad0c3a5]::interface::run_compiler<core[9412a59d758dca42]::result::Result<(), rustc_span[aed5394308446158]::ErrorGuaranteed>, rustc_driver_impl[63f2171535a6fe49]::run_compiler::{closure#0}>::{closure#1}, core[9412a59d758dca42]::result::Result<(), rustc_span[aed5394308446158]::ErrorGuaranteed>>::{closure#0}, core[9412a59d758dca42]::result::Result<(), rustc_span[aed5394308446158]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[9412a59d758dca42]::result::Result<(), rustc_span[aed5394308446158]::ErrorGuaranteed>>::{closure#2} as core[9412a59d758dca42]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  35:        0x1028f352b - std::sys::pal::unix::thread::Thread::new::thread_start::h68d49fa26efc1659
  36:     0x7ff801f5318b - __pthread_start

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/Documents/rustc-ice-2024-06-24-27021.txt` to your bug report

query stack during panic:
#0 [check_well_formed] checking that `<impl at ./BC86F.rs:9:1: 9:37>::bar::{opaque#0}` is well-formed
#1 [check_mod_type_wf] checking that types are well-formed in top-level module
end of query stack
error: aborting due to 2 previous errors

Some errors have detailed explanations: E0275, E0407.
For more information about an error, try `rustc --explain E0275`.

[oli-obk]

huh, did our bug-has-test test diverge from the original reproducer here? and thus we didn't notice it getting fixed?

[matthiaskrgr]

The test got removed in d5bd4e2 🤔

[oli-obk]

yea, we really need some automation adding fixes #xxxxx or at least a bot message when a test gets removed telling the PR author to add that message.

[BoxyUwU]

I think I left this open because the underlying problem isn't fixed even if that exact case worked. I wrote a more detailed comment on the other issue.

I'm not really sure what the right thing to do is in cases like this where the bug in a crashes/*** test gets masked and starts passing but we need to make sure to keep tracking the fact that the compiler is broken.

It feels a bit wrong to mark a PR as fixing a bug when all it does is mask it

[matthiaskrgr]

@oli-obk I've added bit of triabot cfg to #126413 , this is untested though.