nightly from 2023-10-31 can't compile icu4x - crashes with an ICE

[durin42]

Code

I caught this doing an upgrade of rustc nightly in our monorepo. I can reproduce the failure using https://github.com/unicode-org/icu4x and cargo test in the repo root - I'll see about follow-up work to try and reduce it etc, but wanted to file the bug ASAP.

Meta

rustc --version --verbose:

rustc 1.75.0-nightly (9d83ac217 2023-10-31)
binary: rustc
commit-hash: 9d83ac217957eece2189eccf4a7232caec7232ee
commit-date: 2023-10-31
host: x86_64-unknown-linux-gnu
release: 1.75.0-nightly
LLVM version: 17.0.3

Error output

error: could not compile `icu_provider_blob` (lib)
warning: build failed, waiting for other jobs to finish...
thread 'rustc' panicked at compiler/rustc_infer/src/infer/outlives/test_type_match.rs:46:5:
assertion failed: !verify_if_eq_b.has_escaping_bound_vars()
stack backtrace:
   0:     0x7f9b86f69cfc - std::backtrace_rs::backtrace::libunwind::trace::h1c0d6c1feff90834
                               at /rustc/9d83ac217957eece2189eccf4a7232caec7232ee/library/std/src/../../backtrace/src/backtrace/libunwind.rs:104:5
   1:     0x7f9b86f69cfc - std::backtrace_rs::backtrace::trace_unsynchronized::he4dc4a997c5ae9a3
                               at /rustc/9d83ac217957eece2189eccf4a7232caec7232ee/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7f9b86f69cfc - std::sys_common::backtrace::_print_fmt::h5a4f8cab839a8801
                               at /rustc/9d83ac217957eece2189eccf4a7232caec7232ee/library/std/src/sys_common/backtrace.rs:67:5
   3:     0x7f9b86f69cfc - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h633d15e63f261bac
                               at /rustc/9d83ac217957eece2189eccf4a7232caec7232ee/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x7f9b86fcbf50 - core::fmt::rt::Argument::fmt::h7bd3372d26ac29ee
                               at /rustc/9d83ac217957eece2189eccf4a7232caec7232ee/library/core/src/fmt/rt.rs:142:9
   5:     0x7f9b86fcbf50 - core::fmt::write::h81c224801dea0c8c
                               at /rustc/9d83ac217957eece2189eccf4a7232caec7232ee/library/core/src/fmt/mod.rs:1117:17
   6:     0x7f9b86f5dc1f - std::io::Write::write_fmt::h5d5fd4c0f9d7aaa2
                               at /rustc/9d83ac217957eece2189eccf4a7232caec7232ee/library/std/src/io/mod.rs:1763:15
   7:     0x7f9b86f69ae4 - std::sys_common::backtrace::_print::hae2beb76b35b9dac
                               at /rustc/9d83ac217957eece2189eccf4a7232caec7232ee/library/std/src/sys_common/backtrace.rs:47:5
   8:     0x7f9b86f69ae4 - std::sys_common::backtrace::print::hbc2e16b509b271b5
                               at /rustc/9d83ac217957eece2189eccf4a7232caec7232ee/library/std/src/sys_common/backtrace.rs:34:9
   9:     0x7f9b86f6c777 - std::panicking::default_hook::{{closure}}::hdd572dcbcaa64ada
  10:     0x7f9b86f6c4df - std::panicking::default_hook::h3f7cc4d3b39ae3db
                               at /rustc/9d83ac217957eece2189eccf4a7232caec7232ee/library/std/src/panicking.rs:292:9
  11:     0x7f9b89ae24f0 - std[75c6166aa02c8cf6]::panicking::update_hook::<alloc[89c5f4ce44f84c28]::boxed::Box<rustc_driver_impl[8683beda356c97ae]::install_ice_hook::{closure#0}>>::{closure#0}
  12:     0x7f9b86f6ceb8 - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::h9679028235a1e1c1
                               at /rustc/9d83ac217957eece2189eccf4a7232caec7232ee/library/alloc/src/boxed.rs:2021:9
  13:     0x7f9b86f6ceb8 - std::panicking::rust_panic_with_hook::hd2051524a5282492
                               at /rustc/9d83ac217957eece2189eccf4a7232caec7232ee/library/std/src/panicking.rs:783:13
  14:     0x7f9b86f6cbd9 - std::panicking::begin_panic_handler::{{closure}}::h699c051ec6e2b537
                               at /rustc/9d83ac217957eece2189eccf4a7232caec7232ee/library/std/src/panicking.rs:649:13
  15:     0x7f9b86f6a1c6 - std::sys_common::backtrace::__rust_end_short_backtrace::h5d4269c5675c7d12
                               at /rustc/9d83ac217957eece2189eccf4a7232caec7232ee/library/std/src/sys_common/backtrace.rs:170:18
  16:     0x7f9b86f6c972 - rust_begin_unwind
                               at /rustc/9d83ac217957eece2189eccf4a7232caec7232ee/library/std/src/panicking.rs:645:5
  17:     0x7f9b86fc8675 - core::panicking::panic_fmt::hd8a918fb3507036f
                               at /rustc/9d83ac217957eece2189eccf4a7232caec7232ee/library/core/src/panicking.rs:72:14
  18:     0x7f9b86fc8713 - core::panicking::panic::h3d02fed75a814cd3
                               at /rustc/9d83ac217957eece2189eccf4a7232caec7232ee/library/core/src/panicking.rs:127:5
  19:     0x7f9b8bbe76c5 - rustc_infer[5a3154a4da0b7220]::infer::outlives::test_type_match::extract_verify_if_eq
  20:     0x7f9b8bdf422e - <core[b9f207e078deabe9]::iter::adapters::filter_map::FilterMap<core[b9f207e078deabe9]::iter::adapters::chain::Chain<rustc_middle[8603c91d0eb8a1dd]::ty::generic_args::IterInstantiated<&rustc_middle[8603c91d0eb8a1dd]::ty::list::List<rustc_middle[8603c91d0eb8a1dd]::ty::Clause>>, core[b9f207e078deabe9]::iter::adapters::copied::Copied<core[b9f207e078deabe9]::slice::iter::Iter<rustc_middle[8603c91d0eb8a1dd]::ty::Clause>>>, <rustc_infer[5a3154a4da0b7220]::infer::outlives::for_liveness::FreeRegionsVisitor<<rustc_borrowck[6c6400a0a3b5eec2]::type_check::liveness::trace::LivenessContext>::make_all_regions_live<rustc_middle[8603c91d0eb8a1dd]::ty::generic_args::GenericArg>::{closure#0}> as rustc_type_ir[ef25096afbba3fa8]::visit::TypeVisitor<rustc_middle[8603c91d0eb8a1dd]::ty::context::TyCtxt>>::visit_ty::{closure#0}> as core[b9f207e078deabe9]::iter::traits::iterator::Iterator>::next.cold.0
  21:     0x7f9b8af639b5 - <rustc_infer[5a3154a4da0b7220]::infer::outlives::for_liveness::FreeRegionsVisitor<<rustc_borrowck[6c6400a0a3b5eec2]::type_check::liveness::trace::LivenessContext>::make_all_regions_live<rustc_middle[8603c91d0eb8a1dd]::ty::Ty>::{closure#0}> as rustc_type_ir[ef25096afbba3fa8]::visit::TypeVisitor<rustc_middle[8603c91d0eb8a1dd]::ty::context::TyCtxt>>::visit_ty
  22:     0x7f9b8af62c40 - <rustc_infer[5a3154a4da0b7220]::infer::outlives::for_liveness::FreeRegionsVisitor<<rustc_borrowck[6c6400a0a3b5eec2]::type_check::liveness::trace::LivenessContext>::make_all_regions_live<rustc_middle[8603c91d0eb8a1dd]::ty::Ty>::{closure#0}> as rustc_type_ir[ef25096afbba3fa8]::visit::TypeVisitor<rustc_middle[8603c91d0eb8a1dd]::ty::context::TyCtxt>>::visit_ty
  23:     0x7f9b8af63378 - <rustc_infer[5a3154a4da0b7220]::infer::outlives::for_liveness::FreeRegionsVisitor<<rustc_borrowck[6c6400a0a3b5eec2]::type_check::liveness::trace::LivenessContext>::make_all_regions_live<rustc_middle[8603c91d0eb8a1dd]::ty::Ty>::{closure#0}> as rustc_type_ir[ef25096afbba3fa8]::visit::TypeVisitor<rustc_middle[8603c91d0eb8a1dd]::ty::context::TyCtxt>>::visit_ty
  24:     0x7f9b8b902384 - rustc_borrowck[6c6400a0a3b5eec2]::type_check::liveness::trace::trace
  25:     0x7f9b8b5376ff - rustc_borrowck[6c6400a0a3b5eec2]::type_check::type_check
  26:     0x7f9b88415da3 - rustc_borrowck[6c6400a0a3b5eec2]::nll::compute_regions
  27:     0x7f9b8b9d0e8d - rustc_borrowck[6c6400a0a3b5eec2]::do_mir_borrowck
  28:     0x7f9b8b9c0fd7 - rustc_borrowck[6c6400a0a3b5eec2]::mir_borrowck
  29:     0x7f9b8b9c0b97 - rustc_query_impl[5e0ea37d46400eed]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[5e0ea37d46400eed]::query_impl::mir_borrowck::dynamic_query::{closure#2}::{closure#0}, rustc_middle[8603c91d0eb8a1dd]::query::erase::Erased<[u8; 8usize]>>
  30:     0x7f9b8b450e5d - rustc_query_system[ef1bfe6a15550406]::query::plumbing::try_execute_query::<rustc_query_impl[5e0ea37d46400eed]::DynamicConfig<rustc_query_system[ef1bfe6a15550406]::query::caches::VecCache<rustc_span[83a6b6e41b66ef87]::def_id::LocalDefId, rustc_middle[8603c91d0eb8a1dd]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[5e0ea37d46400eed]::plumbing::QueryCtxt, true>
  31:     0x7f9b8b448173 - rustc_query_impl[5e0ea37d46400eed]::query_impl::mir_borrowck::get_query_incr::__rust_end_short_backtrace
  32:     0x7f9b8b4488c8 - rustc_interface[3a72e031d92d94c4]::passes::analysis
  33:     0x7f9b8b4481b5 - rustc_query_impl[5e0ea37d46400eed]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[5e0ea37d46400eed]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[8603c91d0eb8a1dd]::query::erase::Erased<[u8; 1usize]>>
  34:     0x7f9b8b723e84 - rustc_query_system[ef1bfe6a15550406]::query::plumbing::try_execute_query::<rustc_query_impl[5e0ea37d46400eed]::DynamicConfig<rustc_query_system[ef1bfe6a15550406]::query::caches::SingleCache<rustc_middle[8603c91d0eb8a1dd]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[5e0ea37d46400eed]::plumbing::QueryCtxt, true>
  35:     0x7f9b8b723b60 - rustc_query_impl[5e0ea37d46400eed]::query_impl::analysis::get_query_incr::__rust_end_short_backtrace
  36:     0x7f9b8b953ac3 - std[75c6166aa02c8cf6]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[3a72e031d92d94c4]::util::run_in_thread_with_globals<rustc_interface[3a72e031d92d94c4]::interface::run_compiler<core[b9f207e078deabe9]::result::Result<(), rustc_span[83a6b6e41b66ef87]::ErrorGuaranteed>, rustc_driver_impl[8683beda356c97ae]::run_compiler::{closure#1}>::{closure#0}, core[b9f207e078deabe9]::result::Result<(), rustc_span[83a6b6e41b66ef87]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[b9f207e078deabe9]::result::Result<(), rustc_span[83a6b6e41b66ef87]::ErrorGuaranteed>>
  37:     0x7f9b8b952d89 - <<std[75c6166aa02c8cf6]::thread::Builder>::spawn_unchecked_<rustc_interface[3a72e031d92d94c4]::util::run_in_thread_with_globals<rustc_interface[3a72e031d92d94c4]::interface::run_compiler<core[b9f207e078deabe9]::result::Result<(), rustc_span[83a6b6e41b66ef87]::ErrorGuaranteed>, rustc_driver_impl[8683beda356c97ae]::run_compiler::{closure#1}>::{closure#0}, core[b9f207e078deabe9]::result::Result<(), rustc_span[83a6b6e41b66ef87]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[b9f207e078deabe9]::result::Result<(), rustc_span[83a6b6e41b66ef87]::ErrorGuaranteed>>::{closure#1} as core[b9f207e078deabe9]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  38:     0x7f9b86f77c85 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::hbb07097450ba441f
                               at /rustc/9d83ac217957eece2189eccf4a7232caec7232ee/library/alloc/src/boxed.rs:2007:9
  39:     0x7f9b86f77c85 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h1e066a6f7b5acdb1
                               at /rustc/9d83ac217957eece2189eccf4a7232caec7232ee/library/alloc/src/boxed.rs:2007:9
  40:     0x7f9b86f77c85 - std::sys::unix::thread::Thread::new::thread_start::h35349caae5713e8a
                               at /rustc/9d83ac217957eece2189eccf4a7232caec7232ee/library/std/src/sys/unix/thread.rs:108:17
  41:     0x7f9b86d3d3ec - start_thread
                               at ./nptl/pthread_create.c:444:8
  42:     0x7f9b86dbda4c - __GI___clone3
                               at ./misc/../sysdeps/unix/sysv/linux/x86_64/clone3.S:81
  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: please attach the file at `/usr/local/google/home/augie/icu4x/rustc-ice-2023-11-01T17_37_16-3009334.txt` to your bug report

note: compiler flags: --crate-type lib -C embed-bitcode=no -C debuginfo=2 -C incremental=[REDACTED]

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

query stack during panic:
#0 [mir_borrowck] borrow-checking `expander::<impl at components/locid_transform/src/expander.rs:184:1: 184:20>::try_new_compat`
#1 [analysis] running analysis passes on this crate
end of query stack
error: could not compile `icu_locid_transform` (lib)

Backtrace

stack backtrace:
   0: rust_begin_unwind
             at /rustc/9d83ac217957eece2189eccf4a7232caec7232ee/library/std/src/panicking.rs:645:5
   1: core::panicking::panic_fmt
             at /rustc/9d83ac217957eece2189eccf4a7232caec7232ee/library/core/src/panicking.rs:72:14
   2: core::panicking::panic
             at /rustc/9d83ac217957eece2189eccf4a7232caec7232ee/library/core/src/panicking.rs:127:5
   3: rustc_infer::infer::outlives::test_type_match::extract_verify_if_eq
   4: <core::iter::adapters::filter_map::FilterMap<core::iter::adapters::chain::Chain<rustc_middle::ty::generic_args::IterInstantiated<&rustc_middle::ty::list::List<rustc_middle::ty::Clause>>, core::iter::adapters::copied::Copied<core::slice::iter::Iter<rustc_middle::ty::Clause>>>, <rustc_infer::infer::outlives::for_liveness::FreeRegionsVisitor<<rustc_borrowck::type_check::liveness::trace::LivenessContext>::make_all_regions_live<rustc_middle::ty::generic_args::GenericArg>::{closure#0}> as rustc_type_ir::visit::TypeVisitor<rustc_middle::ty::context::TyCtxt>>::visit_ty::{closure#0}> as core::iter::traits::iterator::Iterator>::next.cold.0
   5: <rustc_infer::infer::outlives::for_liveness::FreeRegionsVisitor<<rustc_borrowck::type_check::liveness::trace::LivenessContext>::make_all_regions_live<rustc_middle::ty::Ty>::{closure#0}> as rustc_type_ir::visit::TypeVisitor<rustc_middle::ty::context::TyCtxt>>::visit_ty
   6: <rustc_infer::infer::outlives::for_liveness::FreeRegionsVisitor<<rustc_borrowck::type_check::liveness::trace::LivenessContext>::make_all_regions_live<rustc_middle::ty::Ty>::{closure#0}> as rustc_type_ir::visit::TypeVisitor<rustc_middle::ty::context::TyCtxt>>::visit_ty
   7: <rustc_infer::infer::outlives::for_liveness::FreeRegionsVisitor<<rustc_borrowck::type_check::liveness::trace::LivenessContext>::make_all_regions_live<rustc_middle::ty::Ty>::{closure#0}> as rustc_type_ir::visit::TypeVisitor<rustc_middle::ty::context::TyCtxt>>::visit_ty
   8: rustc_borrowck::type_check::liveness::trace::trace
   9: rustc_borrowck::type_check::type_check
  10: rustc_borrowck::nll::compute_regions
  11: rustc_borrowck::do_mir_borrowck
  12: rustc_borrowck::mir_borrowck
      [... omitted 1 frame ...]
  13: rustc_interface::passes::analysis
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

[durin42]

rustc-ice-2023-11-01T17_37_16-3009334.txt

[durin42]

cargo bisect-nightly --start=2023-10-23 --end=2023-10-31 --regress=ice says that it's ec2b311 first present in the 2023-10-30 nightly.

[durin42]

Whoops, this is a dupe of #117455. I guess I should have known Manish would beat me to this.