internal compiler error in clippy

[fanf2]

I am trying to run clippy on this code: https://github.com/fanf2/dnstrie/tree/clippy-ice

I am using: clippy 0.1.52 (9bc8c42b 2021-05-09) on macOS

Output from RUST_BACKTRACE=1 cargo clippy:

error: internal compiler error: compiler/rustc_middle/src/ty/query/mod.rs:279:1: `tcx.item_children(DefId(0:120 ~ dnstrie[da22]::dnsname))` unsupported by its crate

thread 'rustc' panicked at 'Box<Any>', /rustc/9bc8c42bb2f19e745a63f3445f1ac248fb015e53/library/std/src/panic.rs:59:5
stack backtrace:
   0: std::panicking::begin_panic
   1: std::panic::panic_any
   2: rustc_errors::HandlerInner::bug
   3: rustc_errors::Handler::bug
   4: rustc_middle::util::bug::opt_span_bug_fmt::{{closure}}
   5: rustc_middle::ty::context::tls::with_opt::{{closure}}
   6: rustc_middle::ty::context::tls::with_opt
   7: rustc_middle::util::bug::opt_span_bug_fmt
   8: rustc_middle::util::bug::bug_fmt
   9: <rustc_middle::ty::query::Providers as core::default::Default>::default::{{closure}}
  10: core::ops::function::FnOnce::call_once
  11: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  12: rustc_data_structures::stack::ensure_sufficient_stack
  13: rustc_query_system::query::plumbing::force_query_with_job
  14: rustc_query_system::query::plumbing::get_query_impl
  15: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::item_children
  16: <clippy_lints::macro_use::MacroUseImports as rustc_lint::passes::LateLintPass>::check_item
  17: <rustc_lint::late::LateLintPassObjects as rustc_lint::passes::LateLintPass>::check_item
  18: rustc_hir::intravisit::Visitor::visit_nested_item
  19: rustc_hir::intravisit::walk_item
  20: rustc_hir::intravisit::Visitor::visit_nested_item
  21: rustc_hir::intravisit::walk_item
  22: rustc_hir::intravisit::Visitor::visit_nested_item
  23: rustc_hir::intravisit::walk_crate
  24: rustc_lint::late::late_lint_pass_crate
  25: rustc_lint::late::late_lint_crate
  26: rustc_data_structures::sync::join
  27: <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once
  28: rustc_session::utils::<impl rustc_session::session::Session>::time
  29: rustc_interface::passes::analysis
  30: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  31: rustc_data_structures::stack::ensure_sufficient_stack
  32: rustc_query_system::query::plumbing::force_query_with_job
  33: rustc_query_system::query::plumbing::get_query_impl
  34: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::analysis
  35: rustc_interface::passes::QueryContext::enter
  36: rustc_interface::queries::<impl rustc_interface::interface::Compiler>::enter
  37: rustc_span::with_source_map
  38: rustc_interface::interface::create_compiler_and_run
  39: scoped_tls::ScopedKey<T>::set
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

note: the compiler unexpectedly panicked. this is a bug.

note: we would appreciate a bug report: https://github.com/rust-lang/rust-clippy/issues/new

note: Clippy version: clippy 0.1.52 (9bc8c42b 2021-05-09)

query stack during panic:
#0 [item_children] collecting child items of `dnsname`
#1 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to previous error; 2 warnings emitted

error: could not compile `dnstrie`

[fanf2]

Note this code is currently broken work in progress, a total mess 😁

The ICE goes away if I tweak the #[macro_use] a bit,

diff --git src/dnsname/temp.rs src/dnsname/temp.rs
index a223c74..1a39518 100644
--- src/dnsname/temp.rs
+++ src/dnsname/temp.rs
@@ -4,7 +4,6 @@
 //! This kind of name is decompressed and canonicalized to lower case.
 //! The name and label pointers are stored in its workpad.
 
-#[macro_use]
 use super::*;
 use core::convert::TryInto;
 
@@ -64,6 +63,7 @@ impl<'n> std::fmt::Display for TempName {
 
 #[cfg(test)]
 mod test {
+    #[macro_use]
     use super::*;
 
     #[test]

[giraffate]

This is fixed at Rust 1.53 (currently beta) by #7022. So I'm closing this.

Anyway, thanks for the report!