ICE: failed to resolve instance -Zprint-mono-items=eager

[matthiaskrgr]

Code

#![crate_type="lib"]
pub trait Visit {
    fn visit() {}
}

pub trait Array {
    type Element;
}

impl<'a> Visit for () where
    (): Array<Element=&'a ()>,
{}

impl Array for () {
    type Element = ();
}

Meta

rustc --version --verbose:

rustc 1.70.0-nightly (13afbdaa0 2023-03-17)
binary: rustc
commit-hash: 13afbdaa0655dda23d7129e59ac48f1ec88b2084
commit-date: 2023-03-17
host: x86_64-unknown-linux-gnu
release: 1.70.0-nightly
LLVM version: 15.0.7

Error output

rustc file.rs -Zprint-mono-items=eager

<output>

Backtrace

warning: function `visit` is never used
  --> ./icemaker/B478CCFAD84E06AE49B9831574596D9139EECE93258F58974F01E492096D8F59.rs:18:4
   |
18 | fn visit() {}
   |    ^^^^^
   |
   = note: `#[warn(dead_code)]` on by default

error: internal compiler error: compiler/rustc_middle/src/ty/instance.rs:397:18: failed to resolve instance for <() as Visit>::visit

thread 'rustc' panicked at 'Box<dyn Any>', /rustc/13afbdaa0655dda23d7129e59ac48f1ec88b2084/compiler/rustc_errors/src/lib.rs:1644:9
stack backtrace:
   0:     0x7f661ee7d39a - std::backtrace_rs::backtrace::libunwind::trace::h84d2711f38e4d049
                               at /rustc/13afbdaa0655dda23d7129e59ac48f1ec88b2084/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5
   1:     0x7f661ee7d39a - std::backtrace_rs::backtrace::trace_unsynchronized::h07f6ebc5344709db
                               at /rustc/13afbdaa0655dda23d7129e59ac48f1ec88b2084/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7f661ee7d39a - std::sys_common::backtrace::_print_fmt::h05a29271ab24b307
                               at /rustc/13afbdaa0655dda23d7129e59ac48f1ec88b2084/library/std/src/sys_common/backtrace.rs:65:5
   3:     0x7f661ee7d39a - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h2badcaa62266c6d2
                               at /rustc/13afbdaa0655dda23d7129e59ac48f1ec88b2084/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x7f661eee09be - core::fmt::write::h029bd029dcf67de1
                               at /rustc/13afbdaa0655dda23d7129e59ac48f1ec88b2084/library/core/src/fmt/mod.rs:1254:17
   5:     0x7f661ee70225 - std::io::Write::write_fmt::h80e1934b9bd451b8
                               at /rustc/13afbdaa0655dda23d7129e59ac48f1ec88b2084/library/std/src/io/mod.rs:1684:15
   6:     0x7f661ee7d165 - std::sys_common::backtrace::_print::hd15e10f9274c89b0
                               at /rustc/13afbdaa0655dda23d7129e59ac48f1ec88b2084/library/std/src/sys_common/backtrace.rs:47:5
   7:     0x7f661ee7d165 - std::sys_common::backtrace::print::h170965e4e66b5ee4
                               at /rustc/13afbdaa0655dda23d7129e59ac48f1ec88b2084/library/std/src/sys_common/backtrace.rs:34:9
   8:     0x7f661ee7fedf - std::panicking::default_hook::{{closure}}::h0164004bb09e0366
                               at /rustc/13afbdaa0655dda23d7129e59ac48f1ec88b2084/library/std/src/panicking.rs:271:22
   9:     0x7f661ee7fc1b - std::panicking::default_hook::h5e2940911ec5582f
                               at /rustc/13afbdaa0655dda23d7129e59ac48f1ec88b2084/library/std/src/panicking.rs:290:9
  10:     0x7f661dbf2415 - rustc_driver_impl[bad2ed848d64dbdc]::DEFAULT_HOOK::{closure#0}::{closure#0}
  11:     0x7f661ee8071d - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::h0f3cc38fa49d6ba4
                               at /rustc/13afbdaa0655dda23d7129e59ac48f1ec88b2084/library/alloc/src/boxed.rs:2002:9
  12:     0x7f661ee8071d - std::panicking::rust_panic_with_hook::h591d1df500c4db69
                               at /rustc/13afbdaa0655dda23d7129e59ac48f1ec88b2084/library/std/src/panicking.rs:696:13
  13:     0x7f661e12aef1 - std[b4247acdb72724ff]::panicking::begin_panic::<rustc_errors[48bb1377a0478866]::ExplicitBug>::{closure#0}
  14:     0x7f661e128996 - std[b4247acdb72724ff]::sys_common::backtrace::__rust_end_short_backtrace::<std[b4247acdb72724ff]::panicking::begin_panic<rustc_errors[48bb1377a0478866]::ExplicitBug>::{closure#0}, !>
  15:     0x7f661e13ec96 - std[b4247acdb72724ff]::panicking::begin_panic::<rustc_errors[48bb1377a0478866]::ExplicitBug>
  16:     0x7f661e1a10d6 - std[b4247acdb72724ff]::panic::panic_any::<rustc_errors[48bb1377a0478866]::ExplicitBug>
  17:     0x7f661e19e896 - <rustc_errors[48bb1377a0478866]::HandlerInner>::bug::<&alloc[c5857ad37805d36e]::string::String>
  18:     0x7f661e19e560 - <rustc_errors[48bb1377a0478866]::Handler>::bug::<&alloc[c5857ad37805d36e]::string::String>
  19:     0x7f661e19684b - rustc_middle[eaf6378de1cdbfa8]::util::bug::opt_span_bug_fmt::<rustc_span[4d522547309d7b79]::span_encoding::Span>::{closure#0}
  20:     0x7f661e19529a - rustc_middle[eaf6378de1cdbfa8]::ty::context::tls::with_opt::<rustc_middle[eaf6378de1cdbfa8]::util::bug::opt_span_bug_fmt<rustc_span[4d522547309d7b79]::span_encoding::Span>::{closure#0}, !>::{closure#0}
  21:     0x7f661e195266 - rustc_middle[eaf6378de1cdbfa8]::ty::context::tls::with_context_opt::<rustc_middle[eaf6378de1cdbfa8]::ty::context::tls::with_opt<rustc_middle[eaf6378de1cdbfa8]::util::bug::opt_span_bug_fmt<rustc_span[4d522547309d7b79]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
  22:     0x7f661e196796 - rustc_middle[eaf6378de1cdbfa8]::util::bug::opt_span_bug_fmt::<rustc_span[4d522547309d7b79]::span_encoding::Span>
  23:     0x7f661c2874e3 - rustc_middle[eaf6378de1cdbfa8]::util::bug::bug_fmt
  24:     0x7f661d58d342 - <rustc_middle[eaf6378de1cdbfa8]::ty::instance::Instance>::expect_resolve
  25:     0x7f661d09dbb9 - rustc_monomorphize[589fc27a96a813aa]::collector::collect_roots
  26:     0x7f661d094f0e - <rustc_session[8656a7a78cf578e4]::session::Session>::time::<alloc[c5857ad37805d36e]::vec::Vec<rustc_middle[eaf6378de1cdbfa8]::mir::mono::MonoItem>, rustc_monomorphize[589fc27a96a813aa]::collector::collect_crate_mono_items::{closure#0}>
  27:     0x7f661d094cc1 - rustc_monomorphize[589fc27a96a813aa]::collector::collect_crate_mono_items
  28:     0x7f661d093120 - rustc_monomorphize[589fc27a96a813aa]::partitioning::collect_and_partition_mono_items
  29:     0x7f661cde98b2 - rustc_query_system[3b264ab6e948b942]::query::plumbing::try_execute_query::<rustc_query_impl[1cc93b35ef872c79]::queries::collect_and_partition_mono_items, rustc_query_impl[1cc93b35ef872c79]::plumbing::QueryCtxt>
  30:     0x7f661cde956d - <rustc_query_impl[1cc93b35ef872c79]::Queries as rustc_middle[eaf6378de1cdbfa8]::ty::query::QueryEngine>::collect_and_partition_mono_items
  31:     0x7f661d3b3e17 - rustc_codegen_ssa[4bc24aeebcd9fcf0]::back::symbol_export::exported_symbols_provider_local
  32:     0x7f661d35449a - rustc_query_system[3b264ab6e948b942]::query::plumbing::try_execute_query::<rustc_query_impl[1cc93b35ef872c79]::queries::exported_symbols, rustc_query_impl[1cc93b35ef872c79]::plumbing::QueryCtxt>
  33:     0x7f661d3540f1 - <rustc_query_impl[1cc93b35ef872c79]::Queries as rustc_middle[eaf6378de1cdbfa8]::ty::query::QueryEngine>::exported_symbols
  34:     0x7f661ce7eb41 - <rustc_metadata[e926187d3f7f9ccf]::rmeta::encoder::EncodeContext>::encode_crate_root
  35:     0x7f661ce11c53 - rustc_metadata[e926187d3f7f9ccf]::rmeta::encoder::encode_metadata_impl
  36:     0x7f661ce072ac - rustc_data_structures[8426954b093953dd]::sync::join::<rustc_metadata[e926187d3f7f9ccf]::rmeta::encoder::encode_metadata::{closure#0}, rustc_metadata[e926187d3f7f9ccf]::rmeta::encoder::encode_metadata::{closure#1}, (), ()>
  37:     0x7f661ce06fc1 - rustc_metadata[e926187d3f7f9ccf]::rmeta::encoder::encode_metadata
  38:     0x7f661ce0632a - rustc_metadata[e926187d3f7f9ccf]::fs::encode_and_write_metadata
  39:     0x7f661cdfdc9e - rustc_interface[dde792dfc5bb5edd]::passes::start_codegen
  40:     0x7f661cdfaa38 - <rustc_middle[eaf6378de1cdbfa8]::ty::context::GlobalCtxt>::enter::<<rustc_interface[dde792dfc5bb5edd]::queries::Queries>::ongoing_codegen::{closure#0}::{closure#0}, core[9847d4a2e8a02df2]::result::Result<alloc[c5857ad37805d36e]::boxed::Box<dyn core[9847d4a2e8a02df2]::any::Any>, rustc_span[4d522547309d7b79]::ErrorGuaranteed>>
  41:     0x7f661cdf8f94 - <rustc_interface[dde792dfc5bb5edd]::queries::Queries>::ongoing_codegen
  42:     0x7f661cdf8561 - <rustc_interface[dde792dfc5bb5edd]::interface::Compiler>::enter::<rustc_driver_impl[bad2ed848d64dbdc]::run_compiler::{closure#1}::{closure#2}, core[9847d4a2e8a02df2]::result::Result<core[9847d4a2e8a02df2]::option::Option<rustc_interface[dde792dfc5bb5edd]::queries::Linker>, rustc_span[4d522547309d7b79]::ErrorGuaranteed>>
  43:     0x7f661cdf6630 - rustc_span[4d522547309d7b79]::with_source_map::<core[9847d4a2e8a02df2]::result::Result<(), rustc_span[4d522547309d7b79]::ErrorGuaranteed>, rustc_interface[dde792dfc5bb5edd]::interface::run_compiler<core[9847d4a2e8a02df2]::result::Result<(), rustc_span[4d522547309d7b79]::ErrorGuaranteed>, rustc_driver_impl[bad2ed848d64dbdc]::run_compiler::{closure#1}>::{closure#0}::{closure#0}>
  44:     0x7f661cdf5bd9 - std[b4247acdb72724ff]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[dde792dfc5bb5edd]::util::run_in_thread_pool_with_globals<rustc_interface[dde792dfc5bb5edd]::interface::run_compiler<core[9847d4a2e8a02df2]::result::Result<(), rustc_span[4d522547309d7b79]::ErrorGuaranteed>, rustc_driver_impl[bad2ed848d64dbdc]::run_compiler::{closure#1}>::{closure#0}, core[9847d4a2e8a02df2]::result::Result<(), rustc_span[4d522547309d7b79]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[9847d4a2e8a02df2]::result::Result<(), rustc_span[4d522547309d7b79]::ErrorGuaranteed>>
  45:     0x7f661d4e6afa - <<std[b4247acdb72724ff]::thread::Builder>::spawn_unchecked_<rustc_interface[dde792dfc5bb5edd]::util::run_in_thread_pool_with_globals<rustc_interface[dde792dfc5bb5edd]::interface::run_compiler<core[9847d4a2e8a02df2]::result::Result<(), rustc_span[4d522547309d7b79]::ErrorGuaranteed>, rustc_driver_impl[bad2ed848d64dbdc]::run_compiler::{closure#1}>::{closure#0}, core[9847d4a2e8a02df2]::result::Result<(), rustc_span[4d522547309d7b79]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[9847d4a2e8a02df2]::result::Result<(), rustc_span[4d522547309d7b79]::ErrorGuaranteed>>::{closure#1} as core[9847d4a2e8a02df2]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  46:     0x7f661ee8a5f3 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h51bca2043facf7d3
                               at /rustc/13afbdaa0655dda23d7129e59ac48f1ec88b2084/library/alloc/src/boxed.rs:1988:9
  47:     0x7f661ee8a5f3 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h365da710d54db7ab
                               at /rustc/13afbdaa0655dda23d7129e59ac48f1ec88b2084/library/alloc/src/boxed.rs:1988:9
  48:     0x7f661ee8a5f3 - std::sys::unix::thread::Thread::new::thread_start::hb322f3a535acf0fe
                               at /rustc/13afbdaa0655dda23d7129e59ac48f1ec88b2084/library/std/src/sys/unix/thread.rs:108:17
  49:     0x7f661a89ebb5 - <unknown>
  50:     0x7f661a920d90 - <unknown>
  51:                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: rustc 1.70.0-nightly (13afbdaa0 2023-03-17) running on x86_64-unknown-linux-gnu

note: compiler flags: -Z print-mono-items=eager

query stack during panic:
#0 [collect_and_partition_mono_items] collect_and_partition_mono_items
#1 [exported_symbols] collecting exported symbols for crate `0`
end of query stack
error: aborting due to previous error; 1 warning emitted

[matthiaskrgr]

Regression in rust-lang-ci@8435d25

searched nightlies: from nightly-2022-12-02 to nightly-2023-03-18
regressed nightly: nightly-2022-12-13
searched commit range: bdb07a8...37d7de3
regressed commit: 2176e3a

bisected with cargo-bisect-rustc v0.6.5

Host triple: x86_64-unknown-linux-gnu
Reproduce with:

cargo bisect-rustc --script=/home/matthias/vcs/github/rust_bisect/script.sh --test-dir=/home/matthias/vcs/github/rust_bisect/foo