1.97 beta regression: ICE with "`Res::Err` but no error emitted"

[theemathas]

This regression was discovered by the 1.97 beta crater run.

Error output

[INFO] [stdout] note: no errors encountered even though delayed bugs were created
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] 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
[INFO] [stdout] note: those delayed bugs will now be shown as internal compiler errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] 
[INFO] [stdout] error: internal compiler error: `Res::Err` but no error emitted
[INFO] [stdout]    --> src/sync_api.rs:403:5
[INFO] [stdout]     |
[INFO] [stdout] 403 |     crate::count_tokens( text, model )
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout] note: delayed at /rustc-dev/96f70397ed7ba8baf8d1bb541a1ba8e06e3d6f57/compiler/rustc_hir_typeck/src/expr.rs:588:32
[INFO] [stdout]          0: <rustc_errors::DiagCtxtInner>::emit_diagnostic
[INFO] [stdout]          1: <rustc_errors::DiagCtxtHandle>::emit_diagnostic
[INFO] [stdout]          2: <rustc_span::ErrorGuaranteed as rustc_errors::diagnostic::EmissionGuarantee>::emit_producing_guarantee
[INFO] [stdout]          3: <rustc_errors::DiagCtxtHandle>::span_delayed_bug::<rustc_span::span_encoding::Span, &str>
[INFO] [stdout]          4: <rustc_hir_typeck::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
[INFO] [stdout]          5: <rustc_hir_typeck::fn_ctxt::FnCtxt>::check_expr_call
[INFO] [stdout]          6: <rustc_hir_typeck::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
[INFO] [stdout]          7: <rustc_hir_typeck::fn_ctxt::FnCtxt>::check_expr_block
[INFO] [stdout]          8: <rustc_hir_typeck::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
[INFO] [stdout]          9: rustc_hir_typeck::check::check_fn
[INFO] [stdout]         10: rustc_hir_typeck::typeck_with_inspect::{closure#0}
[INFO] [stdout]         11: rustc_query_impl::query_impl::typeck_root::invoke_provider_fn::__rust_begin_short_backtrace
[INFO] [stdout]         12: rustc_query_impl::execution::try_execute_query::<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::ErasedData<[u8; 8]>, rustc_middle::dep_graph::graph::DepNodeIndex>, false>
[INFO] [stdout]         13: rustc_query_impl::query_impl::typeck_root::execute_query_non_incr::__rust_end_short_backtrace
[INFO] [stdout]         14: <rustc_middle::ty::context::TyCtxt>::par_hir_body_owners::<rustc_hir_analysis::check_crate::{closure#1}>::{closure#0}
[INFO] [stdout]         15: rustc_hir_analysis::check_crate
[INFO] [stdout]         16: rustc_interface::passes::analysis
[INFO] [stdout]         17: rustc_query_impl::execution::try_execute_query::<rustc_middle::query::caches::SingleCache<rustc_middle::query::erase::ErasedData<[u8; 0]>>, false>
[INFO] [stdout]         18: rustc_query_impl::query_impl::analysis::execute_query_non_incr::__rust_end_short_backtrace
[INFO] [stdout]         19: rustc_interface::interface::run_compiler::<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}
[INFO] [stdout]         20: std::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface::util::run_in_thread_with_globals<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
[INFO] [stdout]         21: <std::thread::lifecycle::spawn_unchecked<rustc_interface::util::run_in_thread_with_globals<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
[INFO] [stdout]         22: <std::sys::thread::unix::Thread>::new::thread_start
[INFO] [stdout]         23: <unknown>
[INFO] [stdout]         24: clone
[INFO] [stdout]       
[INFO] [stdout]    --> src/sync_api.rs:403:5
[INFO] [stdout]     |
[INFO] [stdout] 403 |     crate::count_tokens( text, model )
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] note: rustc 1.97.0-beta.1 (96f70397e 2026-05-26) running on x86_64-unknown-linux-gnu
[INFO] [stdout] error: internal compiler error[E0618]: expected function, found `{type error}`
[INFO] [stdout]    --> src/sync_api.rs:403:5
[INFO] [stdout]     |
[INFO] [stdout] 403 |     crate::count_tokens( text, model )
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^---------------
[INFO] [stdout]     |     |
[INFO] [stdout]     |     call expression requires function
[INFO] [stdout]     |
[INFO] [stdout] note: delayed at /rustc-dev/96f70397ed7ba8baf8d1bb541a1ba8e06e3d6f57/compiler/rustc_hir_typeck/src/callee.rs:747:34
[INFO] [stdout]          0: <rustc_errors::DiagCtxtInner>::emit_diagnostic
[INFO] [stdout]          1: <rustc_errors::DiagCtxtHandle>::emit_diagnostic
[INFO] [stdout]          2: <rustc_span::ErrorGuaranteed as rustc_errors::diagnostic::EmissionGuarantee>::emit_producing_guarantee
[INFO] [stdout]          3: <rustc_hir_typeck::fn_ctxt::FnCtxt>::check_expr_call
[INFO] [stdout]          4: <rustc_hir_typeck::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
[INFO] [stdout]          5: <rustc_hir_typeck::fn_ctxt::FnCtxt>::check_expr_block
[INFO] [stdout]          6: <rustc_hir_typeck::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
[INFO] [stdout]          7: rustc_hir_typeck::check::check_fn
[INFO] [stdout]          8: rustc_hir_typeck::typeck_with_inspect::{closure#0}
[INFO] [stdout]          9: rustc_query_impl::query_impl::typeck_root::invoke_provider_fn::__rust_begin_short_backtrace
[INFO] [stdout]         10: rustc_query_impl::execution::try_execute_query::<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::ErasedData<[u8; 8]>, rustc_middle::dep_graph::graph::DepNodeIndex>, false>
[INFO] [stdout]         11: rustc_query_impl::query_impl::typeck_root::execute_query_non_incr::__rust_end_short_backtrace
[INFO] [stdout]         12: <rustc_middle::ty::context::TyCtxt>::par_hir_body_owners::<rustc_hir_analysis::check_crate::{closure#1}>::{closure#0}
[INFO] [stdout]         13: rustc_hir_analysis::check_crate
[INFO] [stdout]         14: rustc_interface::passes::analysis
[INFO] [stdout]         15: rustc_query_impl::execution::try_execute_query::<rustc_middle::query::caches::SingleCache<rustc_middle::query::erase::ErasedData<[u8; 0]>>, false>
[INFO] [stdout]         16: rustc_query_impl::query_impl::analysis::execute_query_non_incr::__rust_end_short_backtrace
[INFO] [stdout]         17: rustc_interface::interface::run_compiler::<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}
[INFO] [stdout]         18: std::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface::util::run_in_thread_with_globals<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
[INFO] [stdout]         19: <std::thread::lifecycle::spawn_unchecked<rustc_interface::util::run_in_thread_with_globals<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
[INFO] [stdout]         20: <std::sys::thread::unix::Thread>::new::thread_start
[INFO] [stdout]         21: <unknown>
[INFO] [stdout]         22: clone
[INFO] [stdout]       
[INFO] [stdout]    --> src/sync_api.rs:403:5
[INFO] [stdout]     |
[INFO] [stdout] 403 |     crate::count_tokens( text, model )
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] 
[INFO] [stderr] note: compiler flags: --crate-type lib -C embed-bitcode=no -C debuginfo=2
[INFO] [stderr] 
[INFO] [stderr] note: some of the compiler flags provided by cargo are hidden
[INFO] [stderr] 
[INFO] [stderr] query stack during panic:
[INFO] [stderr] end of query stack
[INFO] [stderr] error: could not compile `api_xai`

https://crater-reports.s3.amazonaws.com/beta-1.97-3-v2/1.97.0-beta.1/reg/api_xai-0.3.0/log.txt

[theemathas]

Possibly another instance of the same issue in the rustdoc crater run:

[INFO] [stdout] note: no errors encountered even though delayed bugs were created
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] note: those delayed bugs will now be shown as internal compiler errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: internal compiler error: `Res::Err` but no error emitted
[INFO] [stdout]   --> src/command/mod.rs:42:14
[INFO] [stdout]    |
[INFO] [stdout] 42 |    .routine( command ::publish )
[INFO] [stdout]    |              ^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout] note: delayed at /rustc-dev/96f70397ed7ba8baf8d1bb541a1ba8e06e3d6f57/compiler/rustc_hir_typeck/src/expr.rs:588:32
[INFO] [stdout]          0: <rustc_errors::DiagCtxtInner>::emit_diagnostic
[INFO] [stdout]          1: <rustc_errors::DiagCtxtHandle>::emit_diagnostic
[INFO] [stdout]          2: <rustc_span::ErrorGuaranteed as rustc_errors::diagnostic::EmissionGuarantee>::emit_producing_guarantee
[INFO] [stdout]          3: <rustc_errors::DiagCtxtHandle>::span_delayed_bug::<rustc_span::span_encoding::Span, &str>
[INFO] [stdout]          4: <rustc_hir_typeck::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args

(Full error is very long, and so is omitted for brevity.)

https://crater-reports.s3.amazonaws.com/beta-rustdoc-1.97-3/1.97.0-beta.1/reg/willbe-0.35.0/log.txt

[theemathas]

what on earth are these two crates (by the same author) doing with their module system...

[theemathas]

Smaller reproducer: repro.zip

src/lib.rs

use mod_interface::meta::mod_interface;

pub fn run() {
    publish();
}

mod private {
    pub fn publish() {}
}

crate::mod_interface! {
    layer publish;
    orphan use publish;
}

src/publish.rs

pub mod orphan {}
pub mod exposed {}
pub mod prelude {}

This is minimized from willbe, and depends on the crate mod_interface. I believe that the api_xai case is the same, as it also depends on mod_interface.