[ICE]: no resolution for an import

[mu001999]

Code

use my_api::self as alias;

Compiling the above code by rustc --crate-type=lib --edition=2024 -Znamespaced-crates --extern 'my_api::utils' main.rs will lead to the ICE. This happens after #155137, because this PR doesn't handle OpenModule.

Trailing self follows OpenModule should work like normal modules.

Meta

rustc --version --verbose:

rustc 1.99.0-nightly (af3d95584 2026-07-09)
binary: rustc
commit-hash: af3d95584dbddcae597890340995509a7fb47a50
commit-date: 2026-07-09
host: aarch64-apple-darwin
release: 1.99.0-nightly
LLVM version: 22.1.8

Error output

note: no errors encountered even though delayed bugs were created

note: those delayed bugs will now be shown as internal compiler errors

error: internal compiler error: no resolution for an import
 --> main.rs:1:5
  |
1 | use my_api::self as alias;
  |     ^^^^^^^^^^^^
  |
note: delayed at /rustc-dev/af3d95584dbddcae597890340995509a7fb47a50/compiler/rustc_ast_lowering/src/lib.rs:1022:24 - disabled backtrace
 --> main.rs:1:5
  |
1 | use my_api::self as alias;
  |     ^^^^^^^^^^^^

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: please make sure that you have updated to the latest nightly

note: please attach the file at `/Users/mu00/repos/playground/rustc-ice-2026-08-04T14_42_19-94109.txt` to your bug report

note: rustc 1.99.0-nightly (af3d95584 2026-07-09) running on aarch64-apple-darwin

note: compiler flags: --crate-type lib -Z namespaced-crates

Backtrace

note: no errors encountered even though delayed bugs were created

note: those delayed bugs will now be shown as internal compiler errors

error: internal compiler error: no resolution for an import
 --> main.rs:1:5
  |
1 | use my_api::self as alias;
  |     ^^^^^^^^^^^^
  |
note: delayed at /rustc-dev/af3d95584dbddcae597890340995509a7fb47a50/compiler/rustc_ast_lowering/src/lib.rs:1022:24
         0: <std::backtrace::Backtrace>::create
         1: <std::backtrace::Backtrace>::capture
         2: <rustc_errors::DiagCtxtInner>::emit_diagnostic
         3: <rustc_errors::DiagCtxtHandle>::emit_diagnostic
         4: <rustc_span::ErrorGuaranteed as rustc_errors::diagnostic::EmissionGuarantee>::emit_producing_guarantee
         5: <rustc_errors::DiagCtxtHandle>::span_delayed_bug::<rustc_span::span_encoding::Span, &str>
         6: <rustc_ast_lowering::LoweringContext>::lower_import_res
         7: <rustc_ast_lowering::LoweringContext>::lower_use_tree
         8: <rustc_ast_lowering::LoweringContext>::lower_item_kind
         9: rustc_ast_lowering::lower_to_hir
        10: rustc_query_impl::query_impl::lower_to_hir::invoke_provider_fn::__rust_begin_short_backtrace
        11: rustc_query_impl::execution::try_execute_query::<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::ErasedData<[u8; 16]>, rustc_middle::dep_graph::graph::DepNodeIndex>, false>
        12: rustc_query_impl::query_impl::lower_to_hir::execute_query_non_incr::__rust_end_short_backtrace
        13: <rustc_middle::hir::provide::{closure#1} as core::ops::function::FnOnce<(rustc_middle::ty::context::TyCtxt, rustc_span::def_id::LocalDefId)>>::call_once
        14: rustc_query_impl::query_impl::hir_owner::invoke_provider_fn::__rust_begin_short_backtrace
        15: rustc_query_impl::execution::try_execute_query::<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::ErasedData<[u8; 32]>, rustc_middle::dep_graph::graph::DepNodeIndex>, false>
        16: rustc_query_impl::query_impl::hir_owner::execute_query_non_incr::__rust_end_short_backtrace
        17: <rustc_middle::ty::context::TyCtxt>::expect_hir_owner_nodes
        18: rustc_middle::hir::map::hir_crate_items
        19: rustc_query_impl::query_impl::hir_crate_items::invoke_provider_fn::__rust_begin_short_backtrace
        20: rustc_query_impl::execution::try_execute_query::<rustc_middle::query::caches::SingleCache<rustc_middle::query::erase::ErasedData<[u8; 8]>>, false>
        21: rustc_query_impl::query_impl::hir_crate_items::execute_query_non_incr::__rust_end_short_backtrace
        22: rustc_interface::passes::analysis
        23: rustc_query_impl::execution::try_execute_query::<rustc_middle::query::caches::SingleCache<rustc_middle::query::erase::ErasedData<[u8; 0]>>, false>
        24: rustc_query_impl::query_impl::analysis::execute_query_non_incr::__rust_end_short_backtrace
        25: rustc_interface::passes::create_and_enter_global_ctxt::<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure#2}>
        26: rustc_interface::interface::run_compiler::<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}
        27: 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}, ()>
        28: <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}
        29: <std::sys::thread::unix::Thread>::new::thread_start
        30: __pthread_cond_wait

 --> main.rs:1:5
  |
1 | use my_api::self as alias;
  |     ^^^^^^^^^^^^

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: please make sure that you have updated to the latest nightly

note: please attach the file at `/Users/mu00/repos/playground/rustc-ice-2026-08-04T14_43_13-94136.txt` to your bug report

note: rustc 1.99.0-nightly (af3d95584 2026-07-09) running on aarch64-apple-darwin

note: compiler flags: --crate-type lib -Z namespaced-crates

query stack during panic:
end of query stack

[JayanAXHF]

@rustbot claim

[petrochenkov]

Hmmm, in tool modules self doesn't produce an error, but doesn't resolve to the module itself, and resolves to a tool attribute instead.

#[rustfmt::self] // ok
fn main() {}

The example in #160512 (comment) certainly shouldn't ICE, but I'd rather conservatively report an error on any path segment keywords inside both open modules and tool modules.

[mu001999]

I agree with that #[rustfmt::self] should report an error becasue #[rustfmt] will trigger error. But use my_api as alias; works for now, I think use my_api::self as alias; should be equivalent.