rustdoc ice: 'internal error: entered unreachable code', compiler/rustc_resolve/src/lib.rs:3305:6

[matthiaskrgr]

I tried this code:

This code needs to be placed into compiler/rustc_borrowck/src/diagnostics/mod.rs (just overwrite the file).
My repo is currently at f7b4824

//! hello
mod find_all_local_uses;

If you then run rustdoc ./compiler/rustc_borrowck/src/diagnostics/mod.rs, rustdoc will crash:

Meta

rustc --version --verbose:

rustdoc 1.62.0-nightly (8bf93e9b6 2022-04-09)
binary: rustdoc
commit-hash: 8bf93e9b6791acee3a594ed202fdfe45ad9952b5
commit-date: 2022-04-09
host: x86_64-unknown-linux-gnu
release: 1.62.0-nightly
LLVM version: 14.0.0

Backtrace

error[E0433]: failed to resolve: maybe a missing crate `rustc_middle`?
 --> ./compiler/rustc_borrowck/src/diagnostics/find_all_local_uses.rs:3:5
  |
3 | use rustc_middle::mir::visit::{PlaceContext, Visitor};
  |     ^^^^^^^^^^^^ maybe a missing crate `rustc_middle`?

error[E0433]: failed to resolve: maybe a missing crate `rustc_middle`?
 --> ./compiler/rustc_borrowck/src/diagnostics/find_all_local_uses.rs:4:5
  |
4 | use rustc_middle::mir::{Body, Local, Location};
  |     ^^^^^^^^^^^^ maybe a missing crate `rustc_middle`?

error[E0412]: cannot find type `Body` in this scope
 --> ./compiler/rustc_borrowck/src/diagnostics/find_all_local_uses.rs:9:33
  |
9 | pub(super) fn find<'tcx>(body: &Body<'tcx>, local: Local) -> BTreeSet<Location> {
  |                                 ^^^^ not found in this scope

error[E0412]: cannot find type `Local` in this scope
 --> ./compiler/rustc_borrowck/src/diagnostics/find_all_local_uses.rs:9:52
  |
9 | pub(super) fn find<'tcx>(body: &Body<'tcx>, local: Local) -> BTreeSet<Location> {
  |                                                    ^^^^^ not found in this scope

error[E0412]: cannot find type `Location` in this scope
 --> ./compiler/rustc_borrowck/src/diagnostics/find_all_local_uses.rs:9:71
  |
9 | pub(super) fn find<'tcx>(body: &Body<'tcx>, local: Local) -> BTreeSet<Location> {
  |                                                                       ^^^^^^^^ not found in this scope
  |
help: consider importing this struct
  |
1 | use std::panic::Location;
  |

error[E0412]: cannot find type `Local` in this scope
  --> ./compiler/rustc_borrowck/src/diagnostics/find_all_local_uses.rs:16:16
   |
16 |     for_local: Local,
   |                ^^^^^ not found in this scope

error[E0412]: cannot find type `Location` in this scope
  --> ./compiler/rustc_borrowck/src/diagnostics/find_all_local_uses.rs:17:20
   |
17 |     uses: BTreeSet<Location>,
   |                    ^^^^^^^^ not found in this scope
   |
help: consider importing this struct
   |
1  | use std::panic::Location;
   |

error[E0405]: cannot find trait `Visitor` in this scope
  --> ./compiler/rustc_borrowck/src/diagnostics/find_all_local_uses.rs:20:12
   |
20 | impl<'tcx> Visitor<'tcx> for AllLocalUsesVisitor {
   |            ^^^^^^^ not found in this scope

error[E0412]: cannot find type `Local` in this scope
  --> ./compiler/rustc_borrowck/src/diagnostics/find_all_local_uses.rs:21:39
   |
21 |     fn visit_local(&mut self, local: &Local, _context: PlaceContext, location: Location) {
   |                                       ^^^^^ not found in this scope

error[E0412]: cannot find type `PlaceContext` in this scope
  --> ./compiler/rustc_borrowck/src/diagnostics/find_all_local_uses.rs:21:56
   |
21 |     fn visit_local(&mut self, local: &Local, _context: PlaceContext, location: Location) {
   |                                                        ^^^^^^^^^^^^ not found in this scope

error[E0412]: cannot find type `Location` in this scope
  --> ./compiler/rustc_borrowck/src/diagnostics/find_all_local_uses.rs:21:80
   |
21 |     fn visit_local(&mut self, local: &Local, _context: PlaceContext, location: Location) {
   |                                                                                ^^^^^^^^ not found in this scope
   |
help: consider importing this struct
   |
1  | use std::panic::Location;
   |

thread 'rustc' panicked at 'internal error: entered unreachable code', compiler/rustc_resolve/src/lib.rs:3305:67
stack backtrace:
   0:     0x7ff4d549e00d - std::backtrace_rs::backtrace::libunwind::trace::h06b71e168fca8ca7
                               at /rustc/8bf93e9b6791acee3a594ed202fdfe45ad9952b5/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5
   1:     0x7ff4d549e00d - std::backtrace_rs::backtrace::trace_unsynchronized::hd5c568c45ebf115f
                               at /rustc/8bf93e9b6791acee3a594ed202fdfe45ad9952b5/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7ff4d549e00d - std::sys_common::backtrace::_print_fmt::h2207f18151caed70
                               at /rustc/8bf93e9b6791acee3a594ed202fdfe45ad9952b5/library/std/src/sys_common/backtrace.rs:66:5
   3:     0x7ff4d549e00d - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hec1ef25b87918dac
                               at /rustc/8bf93e9b6791acee3a594ed202fdfe45ad9952b5/library/std/src/sys_common/backtrace.rs:45:22
   4:     0x7ff4d54f7d2c - core::fmt::write::h3bdfdbc9caaeb5c4
                               at /rustc/8bf93e9b6791acee3a594ed202fdfe45ad9952b5/library/core/src/fmt/mod.rs:1194:17
   5:     0x7ff4d548f8d1 - std::io::Write::write_fmt::h75f007d851ff8f3e
                               at /rustc/8bf93e9b6791acee3a594ed202fdfe45ad9952b5/library/std/src/io/mod.rs:1655:15
   6:     0x7ff4d54a0f25 - std::sys_common::backtrace::_print::h8cb608922c1cc56d
                               at /rustc/8bf93e9b6791acee3a594ed202fdfe45ad9952b5/library/std/src/sys_common/backtrace.rs:48:5
   7:     0x7ff4d54a0f25 - std::sys_common::backtrace::print::h69d750eeeb320760
                               at /rustc/8bf93e9b6791acee3a594ed202fdfe45ad9952b5/library/std/src/sys_common/backtrace.rs:35:9
   8:     0x7ff4d54a0f25 - std::panicking::default_hook::{{closure}}::h220d8c7b31c1776e
                               at /rustc/8bf93e9b6791acee3a594ed202fdfe45ad9952b5/library/std/src/panicking.rs:295:22
   9:     0x7ff4d54a0b99 - std::panicking::default_hook::hd732eb9b63a7d08e
                               at /rustc/8bf93e9b6791acee3a594ed202fdfe45ad9952b5/library/std/src/panicking.rs:314:9
  10:     0x7ff4d5ccf3c1 - rustc_driver[3655e38759671b1e]::DEFAULT_HOOK::{closure#0}::{closure#0}
  11:     0x7ff4d54a16c0 - std::panicking::rust_panic_with_hook::he731ea0e4d942ce4
                               at /rustc/8bf93e9b6791acee3a594ed202fdfe45ad9952b5/library/std/src/panicking.rs:702:17
  12:     0x7ff4d54a14b9 - std::panicking::begin_panic_handler::{{closure}}::h7572f87a59230791
                               at /rustc/8bf93e9b6791acee3a594ed202fdfe45ad9952b5/library/std/src/panicking.rs:586:13
  13:     0x7ff4d549e4c4 - std::sys_common::backtrace::__rust_end_short_backtrace::ha3eefb66086a857c
                               at /rustc/8bf93e9b6791acee3a594ed202fdfe45ad9952b5/library/std/src/sys_common/backtrace.rs:138:18
  14:     0x7ff4d54a1229 - rust_begin_unwind
                               at /rustc/8bf93e9b6791acee3a594ed202fdfe45ad9952b5/library/std/src/panicking.rs:584:5
  15:     0x7ff4d5465773 - core::panicking::panic_fmt::h4508dc135e264600
                               at /rustc/8bf93e9b6791acee3a594ed202fdfe45ad9952b5/library/core/src/panicking.rs:142:14
  16:     0x7ff4d546563d - core::panicking::panic::hed1ca88aad7c3049
                               at /rustc/8bf93e9b6791acee3a594ed202fdfe45ad9952b5/library/core/src/panicking.rs:48:5
  17:     0x7ff4d6130459 - <rustc_resolve[577bf44bd1426e45]::Resolver>::resolve_rustdoc_path
  18:     0x558d3f747622 - <rustdoc[31e9a93f42be1f5]::passes::collect_intra_doc_links::early::EarlyDocLinkResolver>::load_links_in_attrs
  19:     0x558d3f747ce0 - <rustdoc[31e9a93f42be1f5]::passes::collect_intra_doc_links::early::EarlyDocLinkResolver as rustc_ast[139425a543286658]::visit::Visitor>::visit_item
  20:     0x558d3f79bd2b - rustc_ast[139425a543286658]::visit::walk_item::<rustdoc[31e9a93f42be1f5]::passes::collect_intra_doc_links::early::EarlyDocLinkResolver>
  21:     0x558d3f747d2e - <rustdoc[31e9a93f42be1f5]::passes::collect_intra_doc_links::early::EarlyDocLinkResolver as rustc_ast[139425a543286658]::visit::Visitor>::visit_item
  22:     0x558d3f74559a - rustdoc[31e9a93f42be1f5]::passes::collect_intra_doc_links::early::early_resolve_intra_doc_links
  23:     0x558d3f63962d - <rustc_interface[aab2741c181344a3]::interface::Compiler>::enter::<rustdoc[31e9a93f42be1f5]::main_options::{closure#0}::{closure#0}, core[491626612f8df212]::result::Result<(), rustc_errors[ced839e2d504a56c]::ErrorGuaranteed>>
  24:     0x558d3f7d44f6 - rustc_span[2556154be3375056]::with_source_map::<core[491626612f8df212]::result::Result<(), rustc_errors[ced839e2d504a56c]::ErrorGuaranteed>, rustc_interface[aab2741c181344a3]::interface::create_compiler_and_run<core[491626612f8df212]::result::Result<(), rustc_errors[ced839e2d504a56c]::ErrorGuaranteed>, rustdoc[31e9a93f42be1f5]::main_options::{closure#0}>::{closure#1}>
  25:     0x558d3f670a04 - rustc_interface[aab2741c181344a3]::interface::create_compiler_and_run::<core[491626612f8df212]::result::Result<(), rustc_errors[ced839e2d504a56c]::ErrorGuaranteed>, rustdoc[31e9a93f42be1f5]::main_options::{closure#0}>
  26:     0x558d3f4cd237 - <scoped_tls[8f93d9f95e89128f]::ScopedKey<rustc_span[2556154be3375056]::SessionGlobals>>::set::<rustdoc[31e9a93f42be1f5]::main_args::{closure#0}, core[491626612f8df212]::result::Result<(), rustc_errors[ced839e2d504a56c]::ErrorGuaranteed>>
  27:     0x558d3f6712df - std[4f0b898746aae38d]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[aab2741c181344a3]::util::run_in_thread_pool_with_globals<rustdoc[31e9a93f42be1f5]::main_args::{closure#0}, core[491626612f8df212]::result::Result<(), rustc_errors[ced839e2d504a56c]::ErrorGuaranteed>>::{closure#0}, core[491626612f8df212]::result::Result<(), rustc_errors[ced839e2d504a56c]::ErrorGuaranteed>>
  28:     0x558d3f713a19 - <<std[4f0b898746aae38d]::thread::Builder>::spawn_unchecked_<rustc_interface[aab2741c181344a3]::util::run_in_thread_pool_with_globals<rustdoc[31e9a93f42be1f5]::main_args::{closure#0}, core[491626612f8df212]::result::Result<(), rustc_errors[ced839e2d504a56c]::ErrorGuaranteed>>::{closure#0}, core[491626612f8df212]::result::Result<(), rustc_errors[ced839e2d504a56c]::ErrorGuaranteed>>::{closure#1} as core[491626612f8df212]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  29:     0x7ff4d54ab823 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h6aa3defc4f10dc70
                               at /rustc/8bf93e9b6791acee3a594ed202fdfe45ad9952b5/library/alloc/src/boxed.rs:1858:9
  30:     0x7ff4d54ab823 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h553d7c8698383f07
                               at /rustc/8bf93e9b6791acee3a594ed202fdfe45ad9952b5/library/alloc/src/boxed.rs:1858:9
  31:     0x7ff4d54ab823 - std::sys::unix::thread::Thread::new::thread_start::h0643c814f607f90a
                               at /rustc/8bf93e9b6791acee3a594ed202fdfe45ad9952b5/library/std/src/sys/unix/thread.rs:108:17
  32:     0x7ff4d519b5c2 - start_thread
  33:     0x7ff4d5220584 - __clone
  34:                0x0 - <unknown>

error: internal compiler error: unexpected panic

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 1.62.0-nightly (8bf93e9b6 2022-04-09) running on x86_64-unknown-linux-gnu

query stack during panic:
end of query stack
error: aborting due to 11 previous errors

Some errors have detailed explanations: E0405, E0412, E0433.
For more information about an error, try `rustc --explain E0405`.

[petrochenkov]

This was fixed by #95681, most likely.
I'm not sure which rustdoc do you use, could you check whether it includes that PR?

UPD: Ah, ok, it's 2022-04-09, let me check.

[matthiaskrgr]

I used yesterdays/today(?) nightly which already contains #95681 so I was a bit suspect of this being different issue 😅

[petrochenkov]

Confirmed, this is a different case, and not even a regression from #95337 like #95879 (comment), it reproduces with stable rustc as well.

[petrochenkov]

Minimized:

use unresolved_crate::module::Name;

/// [Name]
pub struct S;

[petrochenkov]

Fixed in #95887.