Stable fails to build a crate: trimmed_def_paths constructed but no error emitted; use `DelayDm` for lints or `with_no_trimmed_paths` for debugging

[wiktor-k]

Hi,

One of my dependencies fails to build on the stable. I've reported this when the compiler was in beta.

Code

The simplest way to reproduce is just to install the crate (for reproducibility here shown in docker):

$ docker run --rm -it rust

// install crate's native dependencies
$ apt update && apt install -y clang llvm pkg-config nettle-dev libpcsclite-dev

$ cargo version
cargo 1.68.0 (115f34552 2023-02-26)

$ cargo install openpgp-card-tools
Compiling pest_derive v2.5.6
error: internal compiler error: no warnings or errors encountered even though `delayed_good_path_bugs` issued
...

Meta

cargo +nightly install openpgp-card-tools succeeds (after installing nightly toolchains with rustup toolchain add nightly).

rustc --version --verbose:

rustc 1.68.0 (2c8cc3432 2023-03-06)
binary: rustc
commit-hash: 2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74
commit-date: 2023-03-06
host: x86_64-unknown-linux-gnu
release: 1.68.0
LLVM version: 15.0.6

Error output

error: internal compiler error: no warnings or errors encountered even though `delayed_good_path_bugs` issued

error: internal compiler error: trimmed_def_paths constructed but no error emitted; use `DelayDm` for lints or `with_no_trimmed_paths` for debugging
  |
  = note: delayed at    0: <rustc_errors::Handler>::delay_good_path_bug::<&str>
             1: rustc_middle::ty::print::pretty::trimmed_def_paths
             2: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::queries::trimmed_def_paths, rustc_query_impl::plumbing::QueryCtxt>
             3: rustc_query_system::query::plumbing::get_query::<rustc_query_impl::queries::trimmed_def_paths, rustc_query_impl::plumbing::QueryCtxt, rustc_middle::dep_graph::dep_node::DepKind>
             4: <rustc_middle::ty::print::pretty::FmtPrinter as rustc_middle::ty::print::Printer>::print_def_path
             5: <rustc_middle::ty::print::pretty::FmtPrinter as rustc_middle::ty::print::Printer>::print_def_path
             6: <rustc_middle::ty::print::pretty::FmtPrinter as rustc_middle::ty::print::pretty::PrettyPrinter>::in_binder::<rustc_middle::ty::sty::ExistentialTraitRef>
             7: <rustc_middle::ty::sty::Binder<rustc_middle::ty::sty::ExistentialTraitRef> as core::fmt::Display>::fmt
             8: <rustc_lint::BuiltinCombinedModuleLateLintPass as rustc_lint::passes::LateLintPass>::check_item
             9: rustc_hir::intravisit::walk_mod::<rustc_lint::late::LateContextAndPass<rustc_lint::BuiltinCombinedModuleLateLintPass>>
            10: rustc_lint::late::late_lint_mod::<rustc_lint::BuiltinCombinedModuleLateLintPass>
            11: rustc_lint::lint_mod
            12: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::queries::lint_mod, rustc_query_impl::plumbing::QueryCtxt>
            13: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::lint_mod
            14: rustc_data_structures::sync::par_for_each_in::<&[rustc_hir::hir_id::OwnerId], <rustc_middle::hir::map::Map>::par_for_each_module<rustc_lint::late::check_crate<rustc_lint::BuiltinCombinedLateLintPass, rustc_interface::passes::analysis::{closure#5}::{closure#1}::{closure#2}::{closure#0}::{closure#0}>::{closure#1}::{closure#0}::{closure#0}>::{closure#0}>
            15: <rustc_session::session::Session>::time::<(), rustc_lint::late::check_crate<rustc_lint::BuiltinCombinedLateLintPass, rustc_interface::passes::analysis::{closure#5}::{closure#1}::{closure#2}::{closure#0}::{closure#0}>::{closure#1}::{closure#0}>
            16: <rustc_session::session::Session>::time::<(), rustc_interface::passes::analysis::{closure#5}::{closure#1}::{closure#2}::{closure#0}>
            17: <core::panic::unwind_safe::AssertUnwindSafe<rustc_interface::passes::analysis::{closure#5}::{closure#1}> as core::ops::function::FnOnce<()>>::call_once
            18: <rustc_session::session::Session>::time::<(), rustc_interface::passes::analysis::{closure#5}>
            19: rustc_interface::passes::analysis
            20: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::queries::analysis, rustc_query_impl::plumbing::QueryCtxt>
            21: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::analysis
            22: <rustc_interface::passes::QueryContext>::enter::<rustc_driver::run_compiler::{closure#1}::{closure#2}::{closure#2}, core::result::Result<(), rustc_errors::ErrorGuaranteed>>
            23: rustc_span::with_source_map::<core::result::Result<(), rustc_errors::ErrorGuaranteed>, rustc_interface::interface::run_compiler<core::result::Result<(), rustc_errors::ErrorGuaranteed>, rustc_driver::run_compiler::{closure#1}>::{closure#0}::{closure#0}>
            24: <scoped_tls::ScopedKey<rustc_span::SessionGlobals>>::set::<rustc_interface::interface::run_compiler<core::result::Result<(), rustc_errors::ErrorGuaranteed>, rustc_driver::run_compiler::{closure#1}>::{closure#0}, core::result::Result<(), rustc_errors::ErrorGuaranteed>>
            25: std::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<core::result::Result<(), rustc_errors::ErrorGuaranteed>, rustc_driver::run_compiler::{closure#1}>::{closure#0}, core::result::Result<(), rustc_errors::ErrorGuaranteed>>::{closure#0}::{closure#0}, core::result::Result<(), rustc_errors::ErrorGuaranteed>>
            26: <<std::thread::Builder>::spawn_unchecked_<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<core::result::Result<(), rustc_errors::ErrorGuaranteed>, rustc_driver::run_compiler::{closure#1}>::{closure#0}, core::result::Result<(), rustc_errors::ErrorGuaranteed>>::{closure#0}::{closure#0}, core::result::Result<(), rustc_errors::ErrorGuaranteed>>::{closure#1} as core::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
            27: <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once
                       at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/alloc/src/boxed.rs:1988:9
            28: <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once
                       at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/alloc/src/boxed.rs:1988:9
            29: std::sys::unix::thread::Thread::new::thread_start
                       at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/sys/unix/thread.rs:108:17
            30: start_thread
            31: clone
          

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 1.68.0 (2c8cc3432 2023-03-06) running on x86_64-unknown-linux-gnu

note: compiler flags: --crate-type lib -C opt-level=3 -C embed-bitcode=no -C codegen-units=1

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

query stack during panic:
end of query stack
error: could not compile `openpgp-card`
warning: build failed, waiting for other jobs to finish...

(Backtrace is the same so I omitted it)

Thanks for help! 👋

[Noratrieb]

@rustbot label +E-easy +E-mentor

Mentoring instructions

The backtrace doesn't contain the exact lint where this is happening, you need a local build to find it.
What is probably happening is that a lint does something.to_string() when building the session diagnostic. This is bad, because it eagerly formats the type, which is very expensive and therefore crashes because the lint is never actually emitted (because it was allowed).
Instead of doing something.to_string(), put the type into a field directly.

If you have more questions, feel free to ask on zulip.

[reez12g]

@rustbot claim

[tmiasko]

I nominated the fix #108162 for backport, if there were to be a point release.

[apiraino]

WG-prioritization assigning priority (Zulip discussion).

@rustbot label -I-prioritize +P-high