internal compiler error in closure

[arnaudgolfouse]

The following code crashes Creusot:

pub fn foo() {
    let my_closure = |x: Option<i32>| match x {
        Some(y) => y,
        None => unreachable!("unwrapped None"),
    };
}

with:

error: internal compiler error: compiler/rustc_middle/src/ty/mod.rs:1607:13: item_name: no name for DefPath { data: [DisambiguatedDefPathData { data: ValueNs("foo"), disambiguator: 0 }, DisambiguatedDefPathData { data: Closure, disambiguator: 0 }], krate: crate0 }

Here is the full backtrace:

Backtrace

thread 'rustc' panicked at compiler/rustc_middle/src/ty/mod.rs:1607:13:

Box<dyn Any>
stack backtrace:
   0:     0x7f1d3b7744c5 - std::backtrace_rs::backtrace::libunwind::trace::h628b2ecbdacacbe5
                               at /rustc/c1a6199e9d92bb785c17a6d7ffd8b8b552f79c10/library/std/src/../../backtrace/src/backtrace/libunwind.rs:116:5
   1:     0x7f1d3b7744c5 - std::backtrace_rs::backtrace::trace_unsynchronized::h933c064eeefc640a
                               at /rustc/c1a6199e9d92bb785c17a6d7ffd8b8b552f79c10/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7f1d3b7744c5 - std::backtrace::Backtrace::create::hbf8273595133b7ce
                               at /rustc/c1a6199e9d92bb785c17a6d7ffd8b8b552f79c10/library/std/src/backtrace.rs:331:13
   3:     0x7f1d3b774415 - std::backtrace::Backtrace::force_capture::ha15f2f878e76c99b
                               at /rustc/c1a6199e9d92bb785c17a6d7ffd8b8b552f79c10/library/std/src/backtrace.rs:312:9
   4:     0x7f1d3ec3ffaf - std[ceb29ca52b686cc8]::panicking::update_hook::<alloc[e8b8252ce035784e]::boxed::Box<rustc_driver_impl[3b5aaec34fa30fe1]::install_ice_hook::{closure#0}>>::{closure#0}
   5:     0x7f1d3b78f1cf - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::h8b761a2279615420
                               at /rustc/c1a6199e9d92bb785c17a6d7ffd8b8b552f79c10/library/alloc/src/boxed.rs:2163:9
   6:     0x7f1d3b78f1cf - std::panicking::rust_panic_with_hook::hc6c98b37b413d838
                               at /rustc/c1a6199e9d92bb785c17a6d7ffd8b8b552f79c10/library/std/src/panicking.rs:808:13
   7:     0x7f1d3ec79d51 - std[ceb29ca52b686cc8]::panicking::begin_panic::<rustc_errors[fdf9495d21ebd0e3]::ExplicitBug>::{closure#0}
   8:     0x7f1d3ec6cd06 - std[ceb29ca52b686cc8]::sys::backtrace::__rust_end_short_backtrace::<std[ceb29ca52b686cc8]::panicking::begin_panic<rustc_errors[fdf9495d21ebd0e3]::ExplicitBug>::{closure#0}, !>
   9:     0x7f1d3ec6ccb6 - std[ceb29ca52b686cc8]::panicking::begin_panic::<rustc_errors[fdf9495d21ebd0e3]::ExplicitBug>
  10:     0x7f1d3ec83391 - <rustc_errors[fdf9495d21ebd0e3]::diagnostic::BugAbort as rustc_errors[fdf9495d21ebd0e3]::diagnostic::EmissionGuarantee>::emit_producing_guarantee
  11:     0x7f1d3f22da14 - rustc_middle[324294c51e6e2842]::util::bug::opt_span_bug_fmt::<rustc_span[f405e44d3411febf]::span_encoding::Span>::{closure#0}
  12:     0x7f1d3f213bba - rustc_middle[324294c51e6e2842]::ty::context::tls::with_opt::<rustc_middle[324294c51e6e2842]::util::bug::opt_span_bug_fmt<rustc_span[f405e44d3411febf]::span_encoding::Span>::{closure#0}, !>::{closure#0}
  13:     0x7f1d3f213a3b - rustc_middle[324294c51e6e2842]::ty::context::tls::with_context_opt::<rustc_middle[324294c51e6e2842]::ty::context::tls::with_opt<rustc_middle[324294c51e6e2842]::util::bug::opt_span_bug_fmt<rustc_span[f405e44d3411febf]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
  14:     0x7f1d3d00cf30 - rustc_middle[324294c51e6e2842]::util::bug::bug_fmt
  15:     0x7f1d4093bd14 - <rustc_middle[324294c51e6e2842]::ty::context::TyCtxt>::item_name
  16:     0x55e857820c4a - creusot::backend::dependency::Dependency::base_ident::haaff2866aa67713e
                               at creusot/creusot/src/backend/dependency.rs:97:44
  17:     0x55e85791b27e - creusot::backend::clone_map::CloneNames::insert::{{closure}}::h7346ac959cc8c60d
                               at creusot/creusot/src/backend/clone_map.rs:301:13
  18:     0x55e857824493 - indexmap::map::core::entry::Entry<K,V>::or_insert_with::hc5620de915533565
                               at ~/.cargo/registry/src/index.crates.io-6f17d22bba15001f/indexmap-2.7.0/src/map/core/entry.rs:76:50
  19:     0x55e857645fc7 - creusot::backend::clone_map::CloneNames::insert::hff6e4717dcf668f8
                               at creusot/creusot/src/backend/clone_map.rs:289:9
  20:     0x55e857c75c50 - <creusot::backend::clone_map::elaborator::ExpansionProxy as creusot::backend::clone_map::Namer>::insert::hfa73b3b1d07be4a5
                               at creusot/creusot/src/backend/clone_map/elaborator.rs:80:9
  21:     0x55e85764a290 - creusot::backend::clone_map::Namer::promoted::hb8a6a9397499b8ec
                               at creusot/creusot/src/backend/clone_map.rs:142:9
  22:     0x55e85786b00a - creusot::backend::program::<impl creusot::translation::fmir::Operand>::to_why::hc1517a63f625eb7c
                               at creusot/creusot/src/backend/program.rs:290:45
  23:     0x55e85786ff42 - creusot::backend::program::<impl creusot::translation::fmir::RValue>::to_why::hbecc970c6db6cc19
                               at creusot/creusot/src/backend/program.rs:308:36
  24:     0x55e85787c54e - creusot::backend::program::<impl creusot::translation::fmir::Statement>::to_why::h1a6474f4987a230d
                               at creusot/creusot/src/backend/program.rs:917:27
  25:     0x55e857879d8d - creusot::backend::program::<impl creusot::translation::fmir::Block>::to_why::h7bed19fe472fcbbe
                               at creusot/creusot/src/backend/program.rs:691:24
  26:     0x55e857bc64cf - creusot::backend::program::component_to_defn::h435f5c067bb10291
                               at creusot/creusot/src/backend/program.rs:228:20
  27:     0x55e857bc50be - creusot::backend::program::to_why::{{closure}}::h621307ee8c2641bb
                               at creusot/creusot/src/backend/program.rs:139:18
  28:     0x55e857bb14a2 - core::iter::adapters::map::map_fold::{{closure}}::h077311c5a1433ce7
                               at /rustc/c1a6199e9d92bb785c17a6d7ffd8b8b552f79c10/library/core/src/iter/adapters/map.rs:89:28
  29:     0x55e857ae4084 - <alloc::vec::into_iter::IntoIter<T,A> as core::iter::traits::iterator::Iterator>::fold::ha9131884bdf0457d
                               at /rustc/c1a6199e9d92bb785c17a6d7ffd8b8b552f79c10/library/alloc/src/vec/into_iter.rs:317:25
  30:     0x55e857b99740 - <core::iter::adapters::map::Map<I,F> as core::iter::traits::iterator::Iterator>::fold::hee446e235b0e6cef
                               at /rustc/c1a6199e9d92bb785c17a6d7ffd8b8b552f79c10/library/core/src/iter/adapters/map.rs:129:9
  31:     0x55e857bab246 - core::iter::traits::iterator::Iterator::for_each::hd90846fb14559cf1
                               at /rustc/c1a6199e9d92bb785c17a6d7ffd8b8b552f79c10/library/core/src/iter/traits/iterator.rs:818:9
  32:     0x55e857705dd4 - alloc::vec::Vec<T,A>::extend_trusted::h6b6e791b50499067
                               at /rustc/c1a6199e9d92bb785c17a6d7ffd8b8b552f79c10/library/alloc/src/vec/mod.rs:3113:17
  33:     0x55e85774075b - <alloc::vec::Vec<T,A> as alloc::vec::spec_extend::SpecExtend<T,I>>::spec_extend::he881e812c70fa4cf
                               at /rustc/c1a6199e9d92bb785c17a6d7ffd8b8b552f79c10/library/alloc/src/vec/spec_extend.rs:26:9
  34:     0x55e8576e9050 - <alloc::vec::Vec<T> as alloc::vec::spec_from_iter_nested::SpecFromIterNested<T,I>>::from_iter::h7a52bcc7d3752dbf
                               at /rustc/c1a6199e9d92bb785c17a6d7ffd8b8b552f79c10/library/alloc/src/vec/spec_from_iter_nested.rs:62:9
  35:     0x55e85772b62e - alloc::vec::in_place_collect::<impl alloc::vec::spec_from_iter::SpecFromIter<T,I> for alloc::vec::Vec<T>>::from_iter::h9c1d6a3c701bb2c1
                               at /rustc/c1a6199e9d92bb785c17a6d7ffd8b8b552f79c10/library/alloc/src/vec/in_place_collect.rs:246:9
  36:     0x55e85773eeb9 - <alloc::vec::Vec<T> as core::iter::traits::collect::FromIterator<T>>::from_iter::hc50fbd712cda699e
                               at /rustc/c1a6199e9d92bb785c17a6d7ffd8b8b552f79c10/library/alloc/src/vec/mod.rs:2977:9
  37:     0x55e857ba9c7e - core::iter::traits::iterator::Iterator::collect::hdb1893665d4e65b5
                               at /rustc/c1a6199e9d92bb785c17a6d7ffd8b8b552f79c10/library/core/src/iter/traits/iterator.rs:2005:9
  38:     0x55e857bc31c1 - creusot::backend::program::to_why::h2ff42f6089bdb63c
                               at creusot/creusot/src/backend/program.rs:137:29
  39:     0x55e857c76404 - <creusot::backend::clone_map::elaborator::ProgElab as creusot::backend::clone_map::elaborator::DepElab>::expand::h5668e4920f94c38a
                               at creusot/creusot/src/backend/clone_map/elaborator.rs:132:20
  40:     0x55e857c7976b - creusot::backend::clone_map::elaborator::Expander::expand::h419d44d50ca67d38
                               at creusot/creusot/src/backend/clone_map/elaborator.rs:349:21
  41:     0x55e857c79133 - creusot::backend::clone_map::elaborator::Expander::update_graph::h26ec795cbb0669b2
                               at creusot/creusot/src/backend/clone_map/elaborator.rs:330:13
  42:     0x55e857646de5 - creusot::backend::clone_map::Dependencies::provide_deps::he57fba83524616d3
                               at creusot/creusot/src/backend/clone_map.rs:378:35
  43:     0x55e857c68e4e - creusot::backend::program::translate_function::h833309c85b9465f2
                               at creusot/creusot/src/backend/program.rs:61:21
  44:     0x55e85764a6e0 - creusot::backend::Why3Generator::translate::hc0f1db556d7d7079
                               at creusot/creusot/src/backend.rs:74:28
  45:     0x55e8579c7cf3 - creusot::translation::after_analysis::h021969fa7d696e94
                               at creusot/creusot/src/translation.rs:122:17
  46:     0x55e85777d7fe - <creusot::callbacks::ToWhy as rustc_driver_impl::Callbacks>::after_expansion::{{closure}}::hdbdbe556a2d3e366
                               at creusot/creusot/src/callbacks.rs:124:21
  47:     0x55e8578fa1d6 - rustc_middle::ty::context::GlobalCtxt::enter::{{closure}}::h1117bbce5553e92f
                               at /rustc/c1a6199e9d92bb785c17a6d7ffd8b8b552f79c10/compiler/rustc_middle/src/ty/context.rs:1336:37
  48:     0x55e857c9ef09 - rustc_middle::ty::context::tls::enter_context::{{closure}}::h8e3e6a616517111e
                               at /rustc/c1a6199e9d92bb785c17a6d7ffd8b8b552f79c10/compiler/rustc_middle/src/ty/context/tls.rs:82:9
  49:     0x55e8575dbb26 - std::thread::local::LocalKey<T>::try_with::h70e9c04f6d8cf1aa
                               at /rustc/c1a6199e9d92bb785c17a6d7ffd8b8b552f79c10/library/std/src/thread/local.rs:283:12
  50:     0x55e8578fa146 - std::thread::local::LocalKey<T>::with::h334e89ebcb8c4708
                               at /rustc/c1a6199e9d92bb785c17a6d7ffd8b8b552f79c10/library/std/src/thread/local.rs:260:9
  51:     0x55e8578fa146 - rustc_middle::ty::context::tls::enter_context::h098ab98c8a074a44
                               at /rustc/c1a6199e9d92bb785c17a6d7ffd8b8b552f79c10/compiler/rustc_middle/src/ty/context/tls.rs:79:9
  52:     0x55e8578fa146 - rustc_middle::ty::context::GlobalCtxt::enter::hd2a461b11739ec26
                               at /rustc/c1a6199e9d92bb785c17a6d7ffd8b8b552f79c10/compiler/rustc_middle/src/ty/context.rs:1336:9
  53:     0x55e8579e83e7 - rustc_interface::queries::QueryResult<&rustc_middle::ty::context::GlobalCtxt>::enter::h00f6fa7b3f7d2861
                               at /rustc/c1a6199e9d92bb785c17a6d7ffd8b8b552f79c10/compiler/rustc_interface/src/queries.rs:64:9
  54:     0x55e85775be02 - <creusot::callbacks::ToWhy as rustc_driver_impl::Callbacks>::after_expansion::h0de48eb0194db7fc
                               at creusot/creusot/src/callbacks.rs:120:17
  55:     0x7f1d40ff8fe4 - rustc_interface[4e0e22890ee77c79]::interface::run_compiler::<core[98a57322150ab76c]::result::Result<(), rustc_span[f405e44d3411febf]::ErrorGuaranteed>, rustc_driver_impl[3b5aaec34fa30fe1]::run_compiler::{closure#0}>::{closure#1}
  56:     0x7f1d40fdfbc9 - std[ceb29ca52b686cc8]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[4e0e22890ee77c79]::util::run_in_thread_with_globals<rustc_interface[4e0e22890ee77c79]::util::run_in_thread_pool_with_globals<rustc_interface[4e0e22890ee77c79]::interface::run_compiler<core[98a57322150ab76c]::result::Result<(), rustc_span[f405e44d3411febf]::ErrorGuaranteed>, rustc_driver_impl[3b5aaec34fa30fe1]::run_compiler::{closure#0}>::{closure#1}, core[98a57322150ab76c]::result::Result<(), rustc_span[f405e44d3411febf]::ErrorGuaranteed>>::{closure#0}, core[98a57322150ab76c]::result::Result<(), rustc_span[f405e44d3411febf]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[98a57322150ab76c]::result::Result<(), rustc_span[f405e44d3411febf]::ErrorGuaranteed>>
  57:     0x7f1d40fdf97a - <<std[ceb29ca52b686cc8]::thread::Builder>::spawn_unchecked_<rustc_interface[4e0e22890ee77c79]::util::run_in_thread_with_globals<rustc_interface[4e0e22890ee77c79]::util::run_in_thread_pool_with_globals<rustc_interface[4e0e22890ee77c79]::interface::run_compiler<core[98a57322150ab76c]::result::Result<(), rustc_span[f405e44d3411febf]::ErrorGuaranteed>, rustc_driver_impl[3b5aaec34fa30fe1]::run_compiler::{closure#0}>::{closure#1}, core[98a57322150ab76c]::result::Result<(), rustc_span[f405e44d3411febf]::ErrorGuaranteed>>::{closure#0}, core[98a57322150ab76c]::result::Result<(), rustc_span[f405e44d3411febf]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[98a57322150ab76c]::result::Result<(), rustc_span[f405e44d3411febf]::ErrorGuaranteed>>::{closure#1} as core[98a57322150ab76c]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  58:     0x7f1d3b79911b - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h9002d9aae9b2170d
                               at /rustc/c1a6199e9d92bb785c17a6d7ffd8b8b552f79c10/library/alloc/src/boxed.rs:2149:9
  59:     0x7f1d3b79911b - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h444d2f27397e5994
                               at /rustc/c1a6199e9d92bb785c17a6d7ffd8b8b552f79c10/library/alloc/src/boxed.rs:2149:9
  60:     0x7f1d3b79911b - std::sys::pal::unix::thread::Thread::new::thread_start::h041a15ab005af7ee
                               at /rustc/c1a6199e9d92bb785c17a6d7ffd8b8b552f79c10/library/std/src/sys/pal/unix/thread.rs:108:17
  61:     0x7f1d3b468148 - start_thread
  62:     0x7f1d3b4ec0cc - __GI___clone3
  63:                0x0 - <unknown>


rustc version: 1.82.0-nightly (c1a6199e9 2024-07-24)
platform: x86_64-unknown-linux-gnu

query stack during panic:
end of query stack

It seems this happens because the string "unwrapped None" gets promoted to a static, which then tries to fetch the name of the closure via tcx.item_name in creusot/src/backend/dependency.rs:97.