ICE: `assertion failed: !deep_decl.is_glob_import()`

[matthiaskrgr]

auto-reduced (treereduce-rust):

mod openssl {

    pub use self::handwritten::*;

    mod handwritten {
        mod m1 {
            pub struct S {}
        }
        mod m2 {

            #[derive(Default)]
            pub struct S {}
        }

        pub use self::m1::*;
        pub use self::m2::*;
    }
}

pub use openssl::*;

original:

//@ check-pass
// https://github.com/rust-lang/rust/pull/112743#issuecomment-1601986883

#![warn(ambiguous_glob_imports)]

macro_rules! m {
    () => {
      pub fn id() {}
    };
}

mod openssl {
    pub use self::evp::*;
    //~^ WARNING ambiguous glob re-exports
    pub use self::handwritten::*;

    mod evp {
      m!();
    }

    mod handwritten {
    mod m1 {
        pub struct S {}
    }
    mod m2 {
        // Note this derive, it makes this struct macro-expanded,
        // so it doesn't appear in time to participate in the initial resolution of `use m::S`,
        // only in the later validation pass.
        #[derive(Default)]
        pub struct S {}
    }

    // Create a glob vs glob ambiguity
    pub use self::m1::*;
    pub use self::m2::*;
}
}

pub use openssl::*;

fn main() {
    id();
    //~^ WARNING `id` is ambiguous
    //~| WARNING this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
}

Version information

rustc 1.94.0-nightly (1b9ae9edd 2026-01-10)
binary: rustc
commit-hash: 1b9ae9eddcbd3b0105a0828e323c6db5f1e6ad0c
commit-date: 2026-01-10
host: x86_64-unknown-linux-gnu
release: 1.94.0-nightly
LLVM version: 21.1.8

Possibly related line of code:

rust/compiler/rustc_resolve/src/imports.rs

Lines 372 to 384 in 1b9ae9e

	if deep_decl != glob_decl {
	// Some import layers have been removed, need to overwrite.
	assert_ne!(old_deep_decl, old_glob_decl);
	// FIXME: reenable the asserts when `warn_ambiguity` is removed (#149195).
	// assert_ne!(old_deep_decl, deep_decl);
	// assert!(old_deep_decl.is_glob_import());
	assert!(!deep_decl.is_glob_import());
	if glob_decl.is_ambiguity_recursive() {
	glob_decl.warn_ambiguity.set_unchecked(true);
	}
	glob_decl
	} else if glob_decl.res() != old_glob_decl.res() {
	old_glob_decl.ambiguity.set_unchecked(Some(glob_decl));

Command:
/home/matthias/.rustup/toolchains/master/bin/rustc

Program output

thread 'rustc' (4091524) panicked at /rustc-dev/1b9ae9eddcbd3b0105a0828e323c6db5f1e6ad0c/compiler/rustc_resolve/src/imports.rs:378:13:
assertion failed: !deep_decl.is_glob_import()
stack backtrace:
   0:     0x7fb01623a273 - <<std[6938aa076b36c5ac]::sys::backtrace::BacktraceLock>::print::DisplayBacktrace as core[bccd4b2d6cdb7e20]::fmt::Display>::fmt
   1:     0x7fb01680fa08 - core[bccd4b2d6cdb7e20]::fmt::write
   2:     0x7fb0162504f6 - <std[6938aa076b36c5ac]::sys::stdio::unix::Stderr as std[6938aa076b36c5ac]::io::Write>::write_fmt
   3:     0x7fb01620fe68 - std[6938aa076b36c5ac]::panicking::default_hook::{closure#0}
   4:     0x7fb01622db03 - std[6938aa076b36c5ac]::panicking::default_hook
   5:     0x7fb01521089a - std[6938aa076b36c5ac]::panicking::update_hook::<alloc[86015bdb52244da1]::boxed::Box<rustc_driver_impl[350e86f741145418]::install_ice_hook::{closure#1}>>::{closure#0}
   6:     0x7fb01622dde2 - std[6938aa076b36c5ac]::panicking::panic_with_hook
   7:     0x7fb01620ff5a - std[6938aa076b36c5ac]::panicking::panic_handler::{closure#0}
   8:     0x7fb016206be9 - std[6938aa076b36c5ac]::sys::backtrace::__rust_end_short_backtrace::<std[6938aa076b36c5ac]::panicking::panic_handler::{closure#0}, !>
   9:     0x7fb0162119fd - __rustc[3c543be16ed5e038]::rust_begin_unwind
  10:     0x7fb013627eec - core[bccd4b2d6cdb7e20]::panicking::panic_fmt
  11:     0x7fb012aa7672 - core[bccd4b2d6cdb7e20]::panicking::panic
  12:     0x7fb01683a7e1 - <rustc_resolve[51f9131d78059eb1]::Resolver>::try_plant_decl_into_local_module
  13:     0x7fb0168398cc - <rustc_resolve[51f9131d78059eb1]::Resolver>::try_plant_decl_into_local_module
  14:     0x7fb0168398cc - <rustc_resolve[51f9131d78059eb1]::Resolver>::try_plant_decl_into_local_module
  15:     0x7fb0168398cc - <rustc_resolve[51f9131d78059eb1]::Resolver>::try_plant_decl_into_local_module
  16:     0x7fb016f045fa - <rustc_resolve[51f9131d78059eb1]::build_reduced_graph::BuildReducedGraphVisitor as rustc_ast[85e5d7c876d0cc7f]::visit::Visitor>::visit_item
  17:     0x7fb016f105b5 - <rustc_resolve[51f9131d78059eb1]::Resolver as rustc_expand[c61a0465d3b74d74]::base::ResolverExpand>::visit_ast_fragment_with_placeholders
  18:     0x7fb017e30e0e - <rustc_expand[c61a0465d3b74d74]::expand::MacroExpander>::fully_expand_fragment
  19:     0x7fb017e1c052 - <rustc_expand[c61a0465d3b74d74]::expand::MacroExpander>::expand_crate
  20:     0x7fb016e78474 - rustc_interface[9706804fe87156b4]::passes::configure_and_expand
  21:     0x7fb0179f2718 - rustc_interface[9706804fe87156b4]::passes::resolver_for_lowering_raw
  22:     0x7fb0179f248d - rustc_query_impl[283934abf3e4e915]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[283934abf3e4e915]::query_impl::resolver_for_lowering_raw::dynamic_query::{closure#2}::{closure#0}, rustc_middle[11388d43b036737e]::query::erase::Erased<[u8; 16usize]>>
  23:     0x7fb0179f246b - <rustc_query_impl[283934abf3e4e915]::query_impl::resolver_for_lowering_raw::dynamic_query::{closure#2} as core[bccd4b2d6cdb7e20]::ops::function::FnOnce<(rustc_middle[11388d43b036737e]::ty::context::TyCtxt, ())>>::call_once
  24:     0x7fb0179ca81f - rustc_query_system[38817e29eb7d5b8b]::query::plumbing::try_execute_query::<rustc_query_impl[283934abf3e4e915]::DynamicConfig<rustc_query_system[38817e29eb7d5b8b]::query::caches::SingleCache<rustc_middle[11388d43b036737e]::query::erase::Erased<[u8; 16usize]>>, false, false, false>, rustc_query_impl[283934abf3e4e915]::plumbing::QueryCtxt, false>
  25:     0x7fb0179ca37c - rustc_query_impl[283934abf3e4e915]::query_impl::resolver_for_lowering_raw::get_query_non_incr::__rust_end_short_backtrace
  26:     0x7fb017b8917b - <rustc_interface[9706804fe87156b4]::passes::create_and_enter_global_ctxt<core[bccd4b2d6cdb7e20]::option::Option<rustc_interface[9706804fe87156b4]::queries::Linker>, rustc_driver_impl[350e86f741145418]::run_compiler::{closure#0}::{closure#2}>::{closure#2} as core[bccd4b2d6cdb7e20]::ops::function::FnOnce<(&rustc_session[f9d61e7a9f67467e]::session::Session, rustc_middle[11388d43b036737e]::ty::context::CurrentGcx, alloc[86015bdb52244da1]::sync::Arc<rustc_data_structures[4857a5955d067035]::jobserver::Proxy>, &std[6938aa076b36c5ac]::sync::once_lock::OnceLock<rustc_middle[11388d43b036737e]::ty::context::GlobalCtxt>, &rustc_data_structures[4857a5955d067035]::sync::worker_local::WorkerLocal<rustc_middle[11388d43b036737e]::arena::Arena>, &rustc_data_structures[4857a5955d067035]::sync::worker_local::WorkerLocal<rustc_hir[bde87669acea4e53]::Arena>, rustc_driver_impl[350e86f741145418]::run_compiler::{closure#0}::{closure#2})>>::call_once::{shim:vtable#0}
  27:     0x7fb017a7f698 - rustc_interface[9706804fe87156b4]::interface::run_compiler::<(), rustc_driver_impl[350e86f741145418]::run_compiler::{closure#0}>::{closure#1}
  28:     0x7fb0179966fa - std[6938aa076b36c5ac]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[9706804fe87156b4]::util::run_in_thread_with_globals<rustc_interface[9706804fe87156b4]::util::run_in_thread_pool_with_globals<rustc_interface[9706804fe87156b4]::interface::run_compiler<(), rustc_driver_impl[350e86f741145418]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
  29:     0x7fb0179964be - <std[6938aa076b36c5ac]::thread::lifecycle::spawn_unchecked<rustc_interface[9706804fe87156b4]::util::run_in_thread_with_globals<rustc_interface[9706804fe87156b4]::util::run_in_thread_pool_with_globals<rustc_interface[9706804fe87156b4]::interface::run_compiler<(), rustc_driver_impl[350e86f741145418]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core[bccd4b2d6cdb7e20]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  30:     0x7fb017998282 - <std[6938aa076b36c5ac]::sys::thread::unix::Thread>::new::thread_start
  31:     0x7fb01129698b - <unknown>
  32:     0x7fb01131a9cc - <unknown>
  33:                0x0 - <unknown>

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

note: rustc 1.94.0-nightly (1b9ae9edd 2026-01-10) running on x86_64-unknown-linux-gnu

query stack during panic:
#0 [resolver_for_lowering_raw] getting the resolver for lowering
end of query stack

[matthiaskrgr]

probably also related to #150502

[petrochenkov]

Fixed in #150939.