ICE: failed to get layout for `[type error]`: the type `[type error]` has an unknown layout

[FedericoStra]

Hello! This is a strange bug that I'm reporting. I don't have the slightest idea of what it does, nor is it very relevant how I encountered this bug. I report it because it might unveil something important. Anyway, here it is.

Code

Make a new lib with cargo new --lib rustc-bug and put this in src/lib.rs:

/*!
```rust
use rustfmt::lexer::{lex_tokens, Token};
assert!(lex_tokens("Hello!") == Ok(("", vec![Token::Command])));
```
*/

That's it: an empty module with a single documentation comment with a doc-test.

Now, if you are ready for the bang, run cargo test --doc and you'll be welcomed with

error: internal compiler error: compiler/rustc_codegen_llvm/src/context.rs:974:13: failed to get layout for `[type error]`: the type `[type error]` has an unknown layout
 --> src/lib.rs:1:38
  |
2 | fn main() { #[allow(non_snake_case)] fn _doctest_main_src_lib_rs_1_0() {
  |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

The full backtrace is at the end.

Meta

rustc --version --verbose:

rustc 1.64.0 (a55dd71d5 2022-09-19)
binary: rustc
commit-hash: a55dd71d5fb0ec5a6a3a9e8c27b2127ba491ce52
commit-date: 2022-09-19
host: x86_64-unknown-linux-gnu
release: 1.64.0
LLVM version: 14.0.6

The same bug persists if I run it with this nightly version:

rustc 1.66.0-nightly (8b705839c 2022-09-26)
binary: rustc
commit-hash: 8b705839cd656d202e920efa8769cbe43a5ee269
commit-date: 2022-09-26
host: x86_64-unknown-linux-gnu
release: 1.66.0-nightly
LLVM version: 15.0.0

Error output

Backtrace

running 1 test
test src/lib.rs - (line 1) ... FAILED

failures:

---- src/lib.rs - (line 1) stdout ----
error: internal compiler error: compiler/rustc_codegen_llvm/src/context.rs:974:13: failed to get layout for `[type error]`: the type `[type error]` has an unknown layout
 --> src/lib.rs:1:38
  |
2 | fn main() { #[allow(non_snake_case)] fn _doctest_main_src_lib_rs_1_0() {
  |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

thread 'rustc' panicked at 'Box<dyn Any>', /rustc/a55dd71d5fb0ec5a6a3a9e8c27b2127ba491ce52/compiler/rustc_errors/src/lib.rs:1332:9
stack backtrace:
   0:     0x7f8ec2bb919d - std::backtrace_rs::backtrace::libunwind::trace::h9135f25bc195152c
                               at /rustc/a55dd71d5fb0ec5a6a3a9e8c27b2127ba491ce52/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5
   1:     0x7f8ec2bb919d - std::backtrace_rs::backtrace::trace_unsynchronized::h015ee85be510df51
                               at /rustc/a55dd71d5fb0ec5a6a3a9e8c27b2127ba491ce52/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7f8ec2bb919d - std::sys_common::backtrace::_print_fmt::h5fad03caa9652a2c
                               at /rustc/a55dd71d5fb0ec5a6a3a9e8c27b2127ba491ce52/library/std/src/sys_common/backtrace.rs:66:5
   3:     0x7f8ec2bb919d - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h2b42ca28d244e5c7
                               at /rustc/a55dd71d5fb0ec5a6a3a9e8c27b2127ba491ce52/library/std/src/sys_common/backtrace.rs:45:22
   4:     0x7f8ec2c146ac - core::fmt::write::h401e827d053130ed
                               at /rustc/a55dd71d5fb0ec5a6a3a9e8c27b2127ba491ce52/library/core/src/fmt/mod.rs:1198:17
   5:     0x7f8ec2baa4e1 - std::io::Write::write_fmt::hffec93268f5cde32
                               at /rustc/a55dd71d5fb0ec5a6a3a9e8c27b2127ba491ce52/library/std/src/io/mod.rs:1672:15
   6:     0x7f8ec2bbbeb5 - std::sys_common::backtrace::_print::h180c4c706ee1d3fb
                               at /rustc/a55dd71d5fb0ec5a6a3a9e8c27b2127ba491ce52/library/std/src/sys_common/backtrace.rs:48:5
   7:     0x7f8ec2bbbeb5 - std::sys_common::backtrace::print::hd0c35d18765761c9
                               at /rustc/a55dd71d5fb0ec5a6a3a9e8c27b2127ba491ce52/library/std/src/sys_common/backtrace.rs:35:9
   8:     0x7f8ec2bbbeb5 - std::panicking::default_hook::{{closure}}::h1f023310983bc730
                               at /rustc/a55dd71d5fb0ec5a6a3a9e8c27b2127ba491ce52/library/std/src/panicking.rs:295:22
   9:     0x7f8ec2bbbbd1 - std::panicking::default_hook::h188fec3334afd5be
                               at /rustc/a55dd71d5fb0ec5a6a3a9e8c27b2127ba491ce52/library/std/src/panicking.rs:314:9
  10:     0x7f8ec1645484 - rustc_driver[4568cc0a685fd94d]::DEFAULT_HOOK::{closure#0}::{closure#0}
  11:     0x7f8ec2bbc5ea - std::panicking::rust_panic_with_hook::hf26e9d4f97b40096
                               at /rustc/a55dd71d5fb0ec5a6a3a9e8c27b2127ba491ce52/library/std/src/panicking.rs:702:17
  12:     0x7f8ec16fc491 - std[306a94a967d8f5ee]::panicking::begin_panic::<rustc_errors[5fcb1a1f56a762e6]::ExplicitBug>::{closure#0}
  13:     0x7f8ec16fc196 - std[306a94a967d8f5ee]::sys_common::backtrace::__rust_end_short_backtrace::<std[306a94a967d8f5ee]::panicking::begin_panic<rustc_errors[5fcb1a1f56a762e6]::ExplicitBug>::{closure#0}, !>
  14:     0x7f8ec1726bd6 - std[306a94a967d8f5ee]::panicking::begin_panic::<rustc_errors[5fcb1a1f56a762e6]::ExplicitBug>
  15:     0x7f8ec1742d96 - std[306a94a967d8f5ee]::panic::panic_any::<rustc_errors[5fcb1a1f56a762e6]::ExplicitBug>
  16:     0x7f8ec1742531 - <rustc_errors[5fcb1a1f56a762e6]::HandlerInner>::span_bug::<rustc_span[721a57c036170ce]::span_encoding::Span, &alloc[6d6f83537459af52]::string::String>
  17:     0x7f8ec1741d90 - <rustc_errors[5fcb1a1f56a762e6]::Handler>::span_bug::<rustc_span[721a57c036170ce]::span_encoding::Span, &alloc[6d6f83537459af52]::string::String>
  18:     0x7f8ec172e888 - rustc_middle[b6cf56a787d1e2a1]::ty::context::tls::with_opt::<rustc_middle[b6cf56a787d1e2a1]::util::bug::opt_span_bug_fmt<rustc_span[721a57c036170ce]::span_encoding::Span>::{closure#0}, ()>
  19:     0x7f8ec172e726 - rustc_middle[b6cf56a787d1e2a1]::util::bug::opt_span_bug_fmt::<rustc_span[721a57c036170ce]::span_encoding::Span>
  20:     0x7f8ec0167d04 - rustc_middle[b6cf56a787d1e2a1]::util::bug::span_bug_fmt::<rustc_span[721a57c036170ce]::span_encoding::Span>
  21:     0x7f8ec17377a1 - <rustc_codegen_llvm[3e0bcdafb62c313]::context::CodegenCx as rustc_middle[b6cf56a787d1e2a1]::ty::layout::LayoutOfHelpers>::handle_layout_err
  22:     0x7f8ec1731721 - <rustc_codegen_llvm[3e0bcdafb62c313]::context::CodegenCx as rustc_middle[b6cf56a787d1e2a1]::ty::layout::LayoutOf>::spanned_layout_of::{closure#0}
  23:     0x7f8ec01813be - rustc_codegen_ssa[5936c3af92679481]::mir::analyze::non_ssa_locals::<rustc_codegen_llvm[3e0bcdafb62c313]::builder::Builder>
  24:     0x7f8ec014d8bd - rustc_codegen_ssa[5936c3af92679481]::mir::codegen_mir::<rustc_codegen_llvm[3e0bcdafb62c313]::builder::Builder>
  25:     0x7f8ec105bf23 - rustc_codegen_llvm[3e0bcdafb62c313]::base::compile_codegen_unit::module_codegen
  26:     0x7f8ec0b23b19 - <rustc_query_system[8caf4755e287670e]::dep_graph::graph::DepGraph<rustc_middle[b6cf56a787d1e2a1]::dep_graph::dep_node::DepKind>>::with_task::<rustc_middle[b6cf56a787d1e2a1]::ty::context::TyCtxt, rustc_span[721a57c036170ce]::symbol::Symbol, rustc_codegen_ssa[5936c3af92679481]::ModuleCodegen<rustc_codegen_llvm[3e0bcdafb62c313]::ModuleLlvm>>
  27:     0x7f8ec0b224b9 - rustc_codegen_llvm[3e0bcdafb62c313]::base::compile_codegen_unit
  28:     0x7f8ec0b20ace - <rustc_codegen_llvm[3e0bcdafb62c313]::LlvmCodegenBackend as rustc_codegen_ssa[5936c3af92679481]::traits::backend::CodegenBackend>::codegen_crate
  29:     0x7f8ec0dc5bac - <rustc_session[98f7faf1d37bb5fb]::session::Session>::time::<alloc[6d6f83537459af52]::boxed::Box<dyn core[6fcc70bcc91a5bf5]::any::Any>, rustc_interface[f934826ba4c12dd9]::passes::start_codegen::{closure#0}>
  30:     0x7f8ec0dc53b3 - <rustc_interface[f934826ba4c12dd9]::passes::QueryContext>::enter::<<rustc_interface[f934826ba4c12dd9]::queries::Queries>::ongoing_codegen::{closure#0}::{closure#0}, core[6fcc70bcc91a5bf5]::result::Result<alloc[6d6f83537459af52]::boxed::Box<dyn core[6fcc70bcc91a5bf5]::any::Any>, rustc_errors[5fcb1a1f56a762e6]::ErrorGuaranteed>>
  31:     0x7f8ec0dbda0f - <rustc_interface[f934826ba4c12dd9]::queries::Queries>::ongoing_codegen
  32:     0x7f8ec0dbc9b2 - <rustc_interface[f934826ba4c12dd9]::interface::Compiler>::enter::<rustc_driver[4568cc0a685fd94d]::run_compiler::{closure#1}::{closure#2}, core[6fcc70bcc91a5bf5]::result::Result<core[6fcc70bcc91a5bf5]::option::Option<rustc_interface[f934826ba4c12dd9]::queries::Linker>, rustc_errors[5fcb1a1f56a762e6]::ErrorGuaranteed>>
  33:     0x7f8ec0db186a - rustc_span[721a57c036170ce]::with_source_map::<core[6fcc70bcc91a5bf5]::result::Result<(), rustc_errors[5fcb1a1f56a762e6]::ErrorGuaranteed>, rustc_interface[f934826ba4c12dd9]::interface::create_compiler_and_run<core[6fcc70bcc91a5bf5]::result::Result<(), rustc_errors[5fcb1a1f56a762e6]::ErrorGuaranteed>, rustc_driver[4568cc0a685fd94d]::run_compiler::{closure#1}>::{closure#1}>
  34:     0x7f8ec0db11a2 - <scoped_tls[80743de900a7f844]::ScopedKey<rustc_span[721a57c036170ce]::SessionGlobals>>::set::<rustc_interface[f934826ba4c12dd9]::interface::run_compiler<core[6fcc70bcc91a5bf5]::result::Result<(), rustc_errors[5fcb1a1f56a762e6]::ErrorGuaranteed>, rustc_driver[4568cc0a685fd94d]::run_compiler::{closure#1}>::{closure#0}, core[6fcc70bcc91a5bf5]::result::Result<(), rustc_errors[5fcb1a1f56a762e6]::ErrorGuaranteed>>
  35:     0x7f8ec0daf5cf - std[306a94a967d8f5ee]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[f934826ba4c12dd9]::util::run_in_thread_pool_with_globals<rustc_interface[f934826ba4c12dd9]::interface::run_compiler<core[6fcc70bcc91a5bf5]::result::Result<(), rustc_errors[5fcb1a1f56a762e6]::ErrorGuaranteed>, rustc_driver[4568cc0a685fd94d]::run_compiler::{closure#1}>::{closure#0}, core[6fcc70bcc91a5bf5]::result::Result<(), rustc_errors[5fcb1a1f56a762e6]::ErrorGuaranteed>>::{closure#0}, core[6fcc70bcc91a5bf5]::result::Result<(), rustc_errors[5fcb1a1f56a762e6]::ErrorGuaranteed>>
  36:     0x7f8ec14690b9 - <<std[306a94a967d8f5ee]::thread::Builder>::spawn_unchecked_<rustc_interface[f934826ba4c12dd9]::util::run_in_thread_pool_with_globals<rustc_interface[f934826ba4c12dd9]::interface::run_compiler<core[6fcc70bcc91a5bf5]::result::Result<(), rustc_errors[5fcb1a1f56a762e6]::ErrorGuaranteed>, rustc_driver[4568cc0a685fd94d]::run_compiler::{closure#1}>::{closure#0}, core[6fcc70bcc91a5bf5]::result::Result<(), rustc_errors[5fcb1a1f56a762e6]::ErrorGuaranteed>>::{closure#0}, core[6fcc70bcc91a5bf5]::result::Result<(), rustc_errors[5fcb1a1f56a762e6]::ErrorGuaranteed>>::{closure#1} as core[6fcc70bcc91a5bf5]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  37:     0x7f8ec2bc6723 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h56d5fc072706762b
                               at /rustc/a55dd71d5fb0ec5a6a3a9e8c27b2127ba491ce52/library/alloc/src/boxed.rs:1935:9
  38:     0x7f8ec2bc6723 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h41deef8e33b824bb
                               at /rustc/a55dd71d5fb0ec5a6a3a9e8c27b2127ba491ce52/library/alloc/src/boxed.rs:1935:9
  39:     0x7f8ec2bc6723 - std::sys::unix::thread::Thread::new::thread_start::ha6436304a1170bba
                               at /rustc/a55dd71d5fb0ec5a6a3a9e8c27b2127ba491ce52/library/std/src/sys/unix/thread.rs:108:17
  40:     0x7f8ebea9f822 - start_thread
  41:     0x7f8ebea3f450 - clone3
  42:                0x0 - <unknown>

note: 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 1.64.0 (a55dd71d5 2022-09-19) running on x86_64-unknown-linux-gnu

note: compiler flags: --crate-type bin -C codegen-units=1 -C embed-bitcode=no

query stack during panic:
end of query stack
error: aborting due to previous error

Couldn't compile the test.

failures:
    src/lib.rs - (line 1)

test result: FAILED. 0 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.05s

error: test failed, to rerun pass '--doc'

[Noratrieb]

This might not fix the underlying issue but I'll at least make the ICE look less cursed

[Noratrieb]

Btw, I can reproduce this on the latest nightly

rustc 1.66.0-nightly (8b705839c 2022-09-26)
binary: rustc
commit-hash: 8b705839cd656d202e920efa8769cbe43a5ee269
commit-date: 2022-09-26
host: x86_64-unknown-linux-gnu
release: 1.66.0-nightly
LLVM version: 15.0.0

[Noratrieb]

With #102373 I now get this backtrace:

Backtrace

error: internal compiler error: no errors encountered even though `delay_span_bug` issued

error: internal compiler error: `InferCtxt` incorrectly tainted by errors
  |
  = note: delayed at compiler/rustc_infer/src/infer/mod.rs:1282:27

error: internal compiler error: TyKind::Error constructed but no error reported
  |
  = note: delayed at compiler/rustc_hir_analysis/src/check/expr.rs:526:21

error: internal compiler error: TyKind::Error constructed but no error reported
  |
  = note: delayed at compiler/rustc_trait_selection/src/traits/project.rs:1238:30

error: internal compiler error: TyKind::Error constructed but no error reported
  |
  = note: delayed at compiler/rustc_hir_analysis/src/check/fn_ctxt/_impl.rs:724:23

error: internal compiler error: TyKind::Error constructed but no error reported
  |
  = note: delayed at compiler/rustc_hir_analysis/src/check/coercion.rs:176:49

error: internal compiler error: TyKind::Error constructed but no error reported
  |
  = note: delayed at compiler/rustc_hir_analysis/src/check/fn_ctxt/checks.rs:109:29

error: internal compiler error: TyKind::Error constructed but no error reported
  |
  = note: delayed at compiler/rustc_hir_analysis/src/check/coercion.rs:963:53

error: internal compiler error: TyKind::Error constructed but no error reported
  |
  = note: delayed at compiler/rustc_hir_analysis/src/check/coercion.rs:1404:42

error: internal compiler error: TyKind::Error constructed but no error reported
  |
  = note: delayed at compiler/rustc_infer/src/infer/sub.rs:123:31

error: internal compiler error: TyKind::Error constructed but no error reported
  |
  = note: delayed at compiler/rustc_hir_analysis/src/check/fn_ctxt/checks.rs:1536:27

error: internal compiler error: TyKind::Error constructed but no error reported
  |
  = note: delayed at compiler/rustc_hir_analysis/src/check/fallback.rs:109:58

error: internal compiler error: TyKind::Error constructed but no error reported
  |
  = note: delayed at /home/nilsh/projects/rust/compiler/rustc_middle/src/ty/relate.rs:419:59

error: internal compiler error: expected fullfillment errors
  |
  = note: delayed at compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs:210:23

error: internal compiler error: TyKind::Error constructed but no error reported
  |
  = note: delayed at compiler/rustc_mir_build/src/build/mod.rs:627:18

error: internal compiler error: PromoteTemps: MIR had errors
 --> src/lib.rs:1:38
  |
2 | fn main() { #[allow(non_snake_case)] fn _doctest_main_src_lib_rs_1_0() {
  |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |
  = note: delayed at compiler/rustc_const_eval/src/transform/promote_consts.rs:53:22

error: internal compiler error: broken MIR in DefId(0:4 ~ rust_out[b9b2]::main::_doctest_main_src_lib_rs_1_0) ("return type"): bad type [type error]
 --> src/lib.rs:1:38
  |
2 | fn main() { #[allow(non_snake_case)] fn _doctest_main_src_lib_rs_1_0() {
  |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |
  = note: delayed at compiler/rustc_borrowck/src/type_check/mod.rs:523:13

error: internal compiler error: TyKind::Error constructed but no error reported
  |
  = note: delayed at compiler/rustc_borrowck/src/type_check/mod.rs:791:20

error: internal compiler error: broken MIR in DefId(0:4 ~ rust_out[b9b2]::main::_doctest_main_src_lib_rs_1_0) (LocalDecl { mutability: Mut, local_info: None, internal: false, is_block_tail: None, ty: [type error], user_ty: None, source_info: SourceInfo { span: src/lib.rs:2:38: 2:71 (#0), scope: scope[0] } }): bad type [type error]
 --> src/lib.rs:1:38
  |
2 | fn main() { #[allow(non_snake_case)] fn _doctest_main_src_lib_rs_1_0() {
  |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |
  = note: delayed at compiler/rustc_borrowck/src/type_check/mod.rs:523:13

thread 'rustc' panicked at 'Box<dyn Any>', compiler/rustc_errors/src/lib.rs:1535:13
stack backtrace:
   0:     0x7fee569b5ada - std::backtrace_rs::backtrace::libunwind::trace::h8f2eb234454895b5
                               at /home/nilsh/projects/rust/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5
   1:     0x7fee569b5ada - std::backtrace_rs::backtrace::trace_unsynchronized::h92c29b31ac06fd9e
                               at /home/nilsh/projects/rust/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7fee569b5ada - std::sys_common::backtrace::_print_fmt::h18c573bdedef2902
                               at /home/nilsh/projects/rust/library/std/src/sys_common/backtrace.rs:66:5
   3:     0x7fee569b5ada - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h2cc87b43d8a562b6
                               at /home/nilsh/projects/rust/library/std/src/sys_common/backtrace.rs:45:22
   4:     0x7fee56a117f8 - core::fmt::write::hf898e0a9cc3c89a4
                               at /home/nilsh/projects/rust/library/core/src/fmt/mod.rs:1209:17
   5:     0x7fee56980da1 - std::io::Write::write_fmt::h2ad619589edaa38f
                               at /home/nilsh/projects/rust/library/std/src/io/mod.rs:1679:15
   6:     0x7fee569b592f - std::sys_common::backtrace::_print::h96ff3c099826a10a
                               at /home/nilsh/projects/rust/library/std/src/sys_common/backtrace.rs:48:5
   7:     0x7fee569b592f - std::sys_common::backtrace::print::hee5b5a20ab57e326
                               at /home/nilsh/projects/rust/library/std/src/sys_common/backtrace.rs:35:9
   8:     0x7fee5699e6e4 - std::panicking::default_hook::{{closure}}::hdb24a3f35c559c6e
   9:     0x7fee5699e49a - std::panicking::default_hook::ha3e88625b127343c
                               at /home/nilsh/projects/rust/library/std/src/panicking.rs:286:9
  10:     0x7fee57329c04 - <alloc[b389559989e95008]::boxed::Box<dyn for<'a, 'b> core[73fa0f4e5d90a029]::ops::function::Fn<(&'a core[73fa0f4e5d90a029]::panic::panic_info::PanicInfo<'b>,), Output = ()> + core[73fa0f4e5d90a029]::marker::Send + core[73fa0f4e5d90a029]::marker::Sync> as core[73fa0f4e5d90a029]::ops::function::Fn<(&core[73fa0f4e5d90a029]::panic::panic_info::PanicInfo,)>>::call
                               at /home/nilsh/projects/rust/library/alloc/src/boxed.rs:1952:9
  11:     0x7fee57329c04 - rustc_driver[371a0ea167db5f7f]::DEFAULT_HOOK::{closure#0}::{closure#0}
                               at /home/nilsh/projects/rust/compiler/rustc_driver/src/lib.rs:1195:13
  12:     0x7fee5699eb0d - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::hafc548451be5b4cf
                               at /home/nilsh/projects/rust/library/alloc/src/boxed.rs:1952:9
  13:     0x7fee5699eb0d - std::panicking::rust_panic_with_hook::hbd6e17eb7e759fb0
                               at /home/nilsh/projects/rust/library/std/src/panicking.rs:673:13
  14:     0x7fee59cdf713 - std[d559eab05d6b0603]::panicking::begin_panic::<rustc_errors[7f5df6e7b9fd1751]::ExplicitBug>::{closure#0}
                               at /home/nilsh/projects/rust/library/std/src/panicking.rs:589:9
  15:     0x7fee59cdf6c6 - std[d559eab05d6b0603]::sys_common::backtrace::__rust_end_short_backtrace::<std[d559eab05d6b0603]::panicking::begin_panic<rustc_errors[7f5df6e7b9fd1751]::ExplicitBug>::{closure#0}, !>
                               at /home/nilsh/projects/rust/library/std/src/sys_common/backtrace.rs:138:18
  16:     0x7fee572e74c6 - std[d559eab05d6b0603]::panicking::begin_panic::<rustc_errors[7f5df6e7b9fd1751]::ExplicitBug>
                               at /home/nilsh/projects/rust/library/std/src/panicking.rs:588:12
  17:     0x7fee59c89906 - std[d559eab05d6b0603]::panic::panic_any::<rustc_errors[7f5df6e7b9fd1751]::ExplicitBug>
                               at /home/nilsh/projects/rust/library/std/src/panic.rs:61:5
  18:     0x7fee59c8c61c - <rustc_errors[7f5df6e7b9fd1751]::HandlerInner>::flush_delayed::<alloc[b389559989e95008]::vec::Vec<rustc_errors[7f5df6e7b9fd1751]::diagnostic::Diagnostic>, &str>
                               at /home/nilsh/projects/rust/compiler/rustc_errors/src/lib.rs:1535:13
  19:     0x7fee59ca7743 - <rustc_errors[7f5df6e7b9fd1751]::Handler>::flush_delayed
                               at /home/nilsh/projects/rust/compiler/rustc_errors/src/lib.rs:1140:9
  20:     0x7fee57468eb9 - <rustc_interface[7313dbe8dd443abf]::queries::Queries>::ongoing_codegen::{closure#0}::{closure#0}
                               at /home/nilsh/projects/rust/compiler/rustc_interface/src/queries.rs:249:17
  21:     0x7fee57468eb9 - <rustc_interface[7313dbe8dd443abf]::passes::QueryContext>::enter::<<rustc_interface[7313dbe8dd443abf]::queries::Queries>::ongoing_codegen::{closure#0}::{closure#0}, core[73fa0f4e5d90a029]::result::Result<alloc[b389559989e95008]::boxed::Box<dyn core[73fa0f4e5d90a029]::any::Any>, rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>>::{closure#0}
                               at /home/nilsh/projects/rust/compiler/rustc_interface/src/passes.rs:769:42
  22:     0x7fee57468eb9 - rustc_middle[3b85d9020c912d92]::ty::context::tls::enter_context::<<rustc_interface[7313dbe8dd443abf]::passes::QueryContext>::enter<<rustc_interface[7313dbe8dd443abf]::queries::Queries>::ongoing_codegen::{closure#0}::{closure#0}, core[73fa0f4e5d90a029]::result::Result<alloc[b389559989e95008]::boxed::Box<dyn core[73fa0f4e5d90a029]::any::Any>, rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>>::{closure#0}, core[73fa0f4e5d90a029]::result::Result<alloc[b389559989e95008]::boxed::Box<dyn core[73fa0f4e5d90a029]::any::Any>, rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>>::{closure#0}
                               at /home/nilsh/projects/rust/compiler/rustc_middle/src/ty/context.rs:1928:50
  23:     0x7fee57468eb9 - rustc_middle[3b85d9020c912d92]::ty::context::tls::set_tlv::<rustc_middle[3b85d9020c912d92]::ty::context::tls::enter_context<<rustc_interface[7313dbe8dd443abf]::passes::QueryContext>::enter<<rustc_interface[7313dbe8dd443abf]::queries::Queries>::ongoing_codegen::{closure#0}::{closure#0}, core[73fa0f4e5d90a029]::result::Result<alloc[b389559989e95008]::boxed::Box<dyn core[73fa0f4e5d90a029]::any::Any>, rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>>::{closure#0}, core[73fa0f4e5d90a029]::result::Result<alloc[b389559989e95008]::boxed::Box<dyn core[73fa0f4e5d90a029]::any::Any>, rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>>::{closure#0}, core[73fa0f4e5d90a029]::result::Result<alloc[b389559989e95008]::boxed::Box<dyn core[73fa0f4e5d90a029]::any::Any>, rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>>
                               at /home/nilsh/projects/rust/compiler/rustc_middle/src/ty/context.rs:1912:9
  24:     0x7fee57468eb9 - rustc_middle[3b85d9020c912d92]::ty::context::tls::enter_context::<<rustc_interface[7313dbe8dd443abf]::passes::QueryContext>::enter<<rustc_interface[7313dbe8dd443abf]::queries::Queries>::ongoing_codegen::{closure#0}::{closure#0}, core[73fa0f4e5d90a029]::result::Result<alloc[b389559989e95008]::boxed::Box<dyn core[73fa0f4e5d90a029]::any::Any>, rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>>::{closure#0}, core[73fa0f4e5d90a029]::result::Result<alloc[b389559989e95008]::boxed::Box<dyn core[73fa0f4e5d90a029]::any::Any>, rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>>
                               at /home/nilsh/projects/rust/compiler/rustc_middle/src/ty/context.rs:1928:9
  25:     0x7fee57468eb9 - <rustc_interface[7313dbe8dd443abf]::passes::QueryContext>::enter::<<rustc_interface[7313dbe8dd443abf]::queries::Queries>::ongoing_codegen::{closure#0}::{closure#0}, core[73fa0f4e5d90a029]::result::Result<alloc[b389559989e95008]::boxed::Box<dyn core[73fa0f4e5d90a029]::any::Any>, rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>>
                               at /home/nilsh/projects/rust/compiler/rustc_interface/src/passes.rs:769:9
  26:     0x7fee57469bed - <rustc_interface[7313dbe8dd443abf]::queries::Queries>::ongoing_codegen::{closure#0}
                               at /home/nilsh/projects/rust/compiler/rustc_interface/src/queries.rs:243:13
  27:     0x7fee57469bed - <rustc_interface[7313dbe8dd443abf]::queries::Query<alloc[b389559989e95008]::boxed::Box<dyn core[73fa0f4e5d90a029]::any::Any>>>::compute::<<rustc_interface[7313dbe8dd443abf]::queries::Queries>::ongoing_codegen::{closure#0}>
                               at /home/nilsh/projects/rust/compiler/rustc_interface/src/queries.rs:38:28
  28:     0x7fee57330c4e - rustc_driver[371a0ea167db5f7f]::run_compiler::{closure#1}::{closure#2}
                               at /home/nilsh/projects/rust/compiler/rustc_driver/src/lib.rs:408:13
  29:     0x7fee57330c4e - <rustc_interface[7313dbe8dd443abf]::interface::Compiler>::enter::<rustc_driver[371a0ea167db5f7f]::run_compiler::{closure#1}::{closure#2}, core[73fa0f4e5d90a029]::result::Result<core[73fa0f4e5d90a029]::option::Option<rustc_interface[7313dbe8dd443abf]::queries::Linker>, rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>>
                               at /home/nilsh/projects/rust/compiler/rustc_interface/src/queries.rs:379:19
  30:     0x7fee57316ff2 - rustc_driver[371a0ea167db5f7f]::run_compiler::{closure#1}
                               at /home/nilsh/projects/rust/compiler/rustc_driver/src/lib.rs:316:22
  31:     0x7fee57316ff2 - rustc_interface[7313dbe8dd443abf]::interface::create_compiler_and_run::<core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>, rustc_driver[371a0ea167db5f7f]::run_compiler::{closure#1}>::{closure#1}
                               at /home/nilsh/projects/rust/compiler/rustc_interface/src/interface.rs:323:13
  32:     0x7fee57316ff2 - rustc_span[84dbe569a712e516]::with_source_map::<core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>, rustc_interface[7313dbe8dd443abf]::interface::create_compiler_and_run<core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>, rustc_driver[371a0ea167db5f7f]::run_compiler::{closure#1}>::{closure#1}>
                               at /home/nilsh/projects/rust/compiler/rustc_span/src/lib.rs:999:5
  33:     0x7fee57331759 - rustc_interface[7313dbe8dd443abf]::interface::create_compiler_and_run::<core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>, rustc_driver[371a0ea167db5f7f]::run_compiler::{closure#1}>
                               at /home/nilsh/projects/rust/compiler/rustc_interface/src/interface.rs:317:5
  34:     0x7fee57337e82 - rustc_interface[7313dbe8dd443abf]::interface::run_compiler::<core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>, rustc_driver[371a0ea167db5f7f]::run_compiler::{closure#1}>::{closure#0}
                               at /home/nilsh/projects/rust/compiler/rustc_interface/src/interface.rs:339:12
  35:     0x7fee57337e82 - <scoped_tls[4b2a4c8958d0f0a7]::ScopedKey<rustc_span[84dbe569a712e516]::SessionGlobals>>::set::<rustc_interface[7313dbe8dd443abf]::interface::run_compiler<core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>, rustc_driver[371a0ea167db5f7f]::run_compiler::{closure#1}>::{closure#0}, core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>>
                               at /home/nilsh/.cargo/registry/src/github.com-1ecc6299db9ec823/scoped-tls-1.0.0/src/lib.rs:137:9
  36:     0x7fee57303aea - rustc_span[84dbe569a712e516]::create_session_globals_then::<core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>, rustc_interface[7313dbe8dd443abf]::interface::run_compiler<core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>, rustc_driver[371a0ea167db5f7f]::run_compiler::{closure#1}>::{closure#0}>
                               at /home/nilsh/projects/rust/compiler/rustc_span/src/lib.rs:111:5
  37:     0x7fee57303aea - rustc_interface[7313dbe8dd443abf]::util::run_in_thread_pool_with_globals::<rustc_interface[7313dbe8dd443abf]::interface::run_compiler<core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>, rustc_driver[371a0ea167db5f7f]::run_compiler::{closure#1}>::{closure#0}, core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>>::{closure#0}
                               at /home/nilsh/projects/rust/compiler/rustc_interface/src/util.rs:159:32
  38:     0x7fee57303aea - std[d559eab05d6b0603]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[7313dbe8dd443abf]::util::run_in_thread_pool_with_globals<rustc_interface[7313dbe8dd443abf]::interface::run_compiler<core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>, rustc_driver[371a0ea167db5f7f]::run_compiler::{closure#1}>::{closure#0}, core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>>::{closure#0}, core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>>
                               at /home/nilsh/projects/rust/library/std/src/sys_common/backtrace.rs:122:18
  39:     0x7fee5730560e - <std[d559eab05d6b0603]::thread::Builder>::spawn_unchecked_::<rustc_interface[7313dbe8dd443abf]::util::run_in_thread_pool_with_globals<rustc_interface[7313dbe8dd443abf]::interface::run_compiler<core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>, rustc_driver[371a0ea167db5f7f]::run_compiler::{closure#1}>::{closure#0}, core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>>::{closure#0}, core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>>::{closure#1}::{closure#0}
                               at /home/nilsh/projects/rust/library/std/src/thread/mod.rs:514:17
  40:     0x7fee5730560e - <core[73fa0f4e5d90a029]::panic::unwind_safe::AssertUnwindSafe<<std[d559eab05d6b0603]::thread::Builder>::spawn_unchecked_<rustc_interface[7313dbe8dd443abf]::util::run_in_thread_pool_with_globals<rustc_interface[7313dbe8dd443abf]::interface::run_compiler<core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>, rustc_driver[371a0ea167db5f7f]::run_compiler::{closure#1}>::{closure#0}, core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>>::{closure#0}, core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>>::{closure#1}::{closure#0}> as core[73fa0f4e5d90a029]::ops::function::FnOnce<()>>::call_once
                               at /home/nilsh/projects/rust/library/core/src/panic/unwind_safe.rs:271:9
  41:     0x7fee5730560e - std[d559eab05d6b0603]::panicking::try::do_call::<core[73fa0f4e5d90a029]::panic::unwind_safe::AssertUnwindSafe<<std[d559eab05d6b0603]::thread::Builder>::spawn_unchecked_<rustc_interface[7313dbe8dd443abf]::util::run_in_thread_pool_with_globals<rustc_interface[7313dbe8dd443abf]::interface::run_compiler<core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>, rustc_driver[371a0ea167db5f7f]::run_compiler::{closure#1}>::{closure#0}, core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>>::{closure#0}, core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>>::{closure#1}::{closure#0}>, core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>>
                               at /home/nilsh/projects/rust/library/std/src/panicking.rs:464:40
  42:     0x7fee5730560e - std[d559eab05d6b0603]::panicking::try::<core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>, core[73fa0f4e5d90a029]::panic::unwind_safe::AssertUnwindSafe<<std[d559eab05d6b0603]::thread::Builder>::spawn_unchecked_<rustc_interface[7313dbe8dd443abf]::util::run_in_thread_pool_with_globals<rustc_interface[7313dbe8dd443abf]::interface::run_compiler<core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>, rustc_driver[371a0ea167db5f7f]::run_compiler::{closure#1}>::{closure#0}, core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>>::{closure#0}, core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>>::{closure#1}::{closure#0}>>
                               at /home/nilsh/projects/rust/library/std/src/panicking.rs:428:19
  43:     0x7fee5731cf04 - std[d559eab05d6b0603]::panic::catch_unwind::<core[73fa0f4e5d90a029]::panic::unwind_safe::AssertUnwindSafe<<std[d559eab05d6b0603]::thread::Builder>::spawn_unchecked_<rustc_interface[7313dbe8dd443abf]::util::run_in_thread_pool_with_globals<rustc_interface[7313dbe8dd443abf]::interface::run_compiler<core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>, rustc_driver[371a0ea167db5f7f]::run_compiler::{closure#1}>::{closure#0}, core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>>::{closure#0}, core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>>::{closure#1}::{closure#0}>, core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>>
                               at /home/nilsh/projects/rust/library/std/src/panic.rs:137:14
  44:     0x7fee5731cf04 - <std[d559eab05d6b0603]::thread::Builder>::spawn_unchecked_::<rustc_interface[7313dbe8dd443abf]::util::run_in_thread_pool_with_globals<rustc_interface[7313dbe8dd443abf]::interface::run_compiler<core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>, rustc_driver[371a0ea167db5f7f]::run_compiler::{closure#1}>::{closure#0}, core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>>::{closure#0}, core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>>::{closure#1}
                               at /home/nilsh/projects/rust/library/std/src/thread/mod.rs:513:30
  45:     0x7fee5731cf04 - <<std[d559eab05d6b0603]::thread::Builder>::spawn_unchecked_<rustc_interface[7313dbe8dd443abf]::util::run_in_thread_pool_with_globals<rustc_interface[7313dbe8dd443abf]::interface::run_compiler<core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>, rustc_driver[371a0ea167db5f7f]::run_compiler::{closure#1}>::{closure#0}, core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>>::{closure#0}, core[73fa0f4e5d90a029]::result::Result<(), rustc_errors[7f5df6e7b9fd1751]::ErrorGuaranteed>>::{closure#1} as core[73fa0f4e5d90a029]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
                               at /home/nilsh/projects/rust/library/core/src/ops/function.rs:251:5
  46:     0x7fee5697a818 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h73d336d1c9e65b4a
                               at /home/nilsh/projects/rust/library/alloc/src/boxed.rs:1938:9
  47:     0x7fee5697a818 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::ha38990988e6c8e8b
                               at /home/nilsh/projects/rust/library/alloc/src/boxed.rs:1938:9
  48:     0x7fee56995f97 - std::sys::unix::thread::Thread::new::thread_start::h0e8d69c155def017
                               at /home/nilsh/projects/rust/library/std/src/sys/unix/thread.rs:108:17
  49:     0x7fee56750b43 - start_thread
                               at ./nptl/./nptl/pthread_create.c:442:8
  50:     0x7fee567e2a00 - clone3
                               at ./misc/../sysdeps/unix/sysv/linux/x86_64/clone3.S:81
  51:                0x0 - <unknown>

note: 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 1.66.0-dev running on x86_64-unknown-linux-gnu

note: compiler flags: --crate-type bin -C codegen-units=1 -C embed-bitcode=no

query stack during panic:
end of query stack
error: aborting due to 19 previous errors

The error was originally emitted in check_expr_path in hir-analysis when it failed to resolve a path

rust/compiler/rustc_hir_analysis/src/check/expr.rs

Lines 518 to 527 in 57ee5cf

	args: &'tcx [hir::Expr<'tcx>],
	) -> Ty<'tcx> {
	let tcx = self.tcx;
	let (res, opt_ty, segs) =
	self.resolve_ty_and_res_fully_qualified_call(qpath, expr.hir_id, expr.span);
	let ty = match res {
	Res::Err => {
	self.set_tainted_by_errors();
	tcx.ty_error()
	}

[FedericoStra]

This might not fix the underlying issue but I'll at least make the ICE look less cursed

I guess "less cursed" is subjective then 😄

Anyway, the PR seems a good step forward: I didn't know there was a bug in the bug that made it difficult to track down the actual bug. 👍

[Noratrieb]

I have actually experienced the same ICE yesterday in my own code when I was working on AST lowering and lowered things in the wrong order. It seems like this kind of late path resolution failure happens when path resolution initially succeeds, but then something (like a broken AST lowering) happens which causes the path to suddenly stop resolving in typeck. Typeck then doesn't know any better than to create a type error type (which causes the mass of delayed ICEs) and continue, which doesmakes sense, as this path is hit as well when the code has a real path resolution error that is correctly detected and emitted earlier.