ICE "inconsistent resolution for an import" with two enums

[jruderman]

Code

use self::A::*;
use V;
use self::B::*;
enum A {
    V
}
enum B {
    V
}
fn main() {}

Error output

thread 'rustc' panicked at 'compiler/rustc_resolve/src/imports.rs:818: inconsistent resolution for an import', compiler/rustc_middle/src/util/bug.rs:36

Backtrace

stack backtrace:
   0:        0x1028302a6 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h1901ec5c10c2d477
   1:        0x10288ee2a - core::fmt::write::h453ba3b763f16dfb
   2:        0x10282264c - std::io::Write::write_fmt::h35935f9cf41659e0
   3:        0x10283008a - std::sys_common::backtrace::print::h48cb2ddd4d16ad05
   4:        0x1028333d3 - std::panicking::default_hook::{{closure}}::hf85401495f021b7c
   5:        0x102833128 - std::panicking::default_hook::hcc698ed67aaec0db
   6:        0x10e2de5fd - rustc_driver[c6bc39476a4ff69]::DEFAULT_HOOK::{closure#0}::{closure#0}
   7:        0x102833bb7 - std::panicking::rust_panic_with_hook::h4686e220b4123e59
   8:        0x11133abec - std[e853a6d0ec043b70]::panicking::begin_panic::<alloc[374a688e4a400e73]::string::String>::{closure#0}
   9:        0x11133a6e0 - std[e853a6d0ec043b70]::sys_common::backtrace::__rust_end_short_backtrace::<std[e853a6d0ec043b70]::panicking::begin_panic<alloc[374a688e4a400e73]::string::String>::{closure#0}, !>
  10:        0x11305dcec - std[e853a6d0ec043b70]::panicking::begin_panic::<alloc[374a688e4a400e73]::string::String>
  11:        0x11124d51f - std[e853a6d0ec043b70]::panic::panic_any::<alloc[374a688e4a400e73]::string::String>
  12:        0x11124d704 - rustc_middle[d5319f07d231351a]::ty::context::tls::with_context_opt::<rustc_middle[d5319f07d231351a]::ty::context::tls::with_opt<rustc_middle[d5319f07d231351a]::util::bug::opt_span_bug_fmt<rustc_span[db835ecaf6c42563]::span_encoding::Span>::{closure#0}, ()>::{closure#0}, ()>
  13:        0x11124d641 - rustc_middle[d5319f07d231351a]::util::bug::opt_span_bug_fmt::<rustc_span[db835ecaf6c42563]::span_encoding::Span>
  14:        0x11305c3cf - rustc_middle[d5319f07d231351a]::util::bug::span_bug_fmt::<rustc_span[db835ecaf6c42563]::span_encoding::Span>
  15:        0x1112c1754 - <rustc_resolve[90772e7bddb5c4fb]::imports::ImportResolver>::finalize_import::{closure#0}
  16:        0x111322f27 - <rustc_resolve[90772e7bddb5c4fb]::imports::ImportResolver>::finalize_import
  17:        0x111321161 - <rustc_resolve[90772e7bddb5c4fb]::imports::ImportResolver>::finalize_imports
  18:        0x1113303df - <rustc_session[bf9d936332845243]::session::Session>::time::<(), <rustc_resolve[90772e7bddb5c4fb]::Resolver>::resolve_crate::{closure#0}>
  19:        0x10e3a3a17 - rustc_interface[6b0baa6f0acee236]::passes::configure_and_expand
  20:        0x10e3ab3f6 - <rustc_interface[6b0baa6f0acee236]::queries::Queries>::expansion
  21:        0x10e2b6a67 - <rustc_interface[6b0baa6f0acee236]::interface::Compiler>::enter::<rustc_driver[c6bc39476a4ff69]::run_compiler::{closure#1}::{closure#2}, core[e7c8723dd1d9fd02]::result::Result<core[e7c8723dd1d9fd02]::option::Option<rustc_interface[6b0baa6f0acee236]::queries::Linker>, rustc_errors[5974999511236221]::ErrorGuaranteed>>
  22:        0x10e252d5d - rustc_span[db835ecaf6c42563]::with_source_map::<core[e7c8723dd1d9fd02]::result::Result<(), rustc_errors[5974999511236221]::ErrorGuaranteed>, rustc_interface[6b0baa6f0acee236]::interface::run_compiler<core[e7c8723dd1d9fd02]::result::Result<(), rustc_errors[5974999511236221]::ErrorGuaranteed>, rustc_driver[c6bc39476a4ff69]::run_compiler::{closure#1}>::{closure#0}::{closure#0}>
  23:        0x10e2a9a9d - <scoped_tls[9dceb67bf45baec5]::ScopedKey<rustc_span[db835ecaf6c42563]::SessionGlobals>>::set::<rustc_interface[6b0baa6f0acee236]::interface::run_compiler<core[e7c8723dd1d9fd02]::result::Result<(), rustc_errors[5974999511236221]::ErrorGuaranteed>, rustc_driver[c6bc39476a4ff69]::run_compiler::{closure#1}>::{closure#0}, core[e7c8723dd1d9fd02]::result::Result<(), rustc_errors[5974999511236221]::ErrorGuaranteed>>
  24:        0x10e278ffa - std[e853a6d0ec043b70]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[6b0baa6f0acee236]::util::run_in_thread_pool_with_globals<rustc_interface[6b0baa6f0acee236]::interface::run_compiler<core[e7c8723dd1d9fd02]::result::Result<(), rustc_errors[5974999511236221]::ErrorGuaranteed>, rustc_driver[c6bc39476a4ff69]::run_compiler::{closure#1}>::{closure#0}, core[e7c8723dd1d9fd02]::result::Result<(), rustc_errors[5974999511236221]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[e7c8723dd1d9fd02]::result::Result<(), rustc_errors[5974999511236221]::ErrorGuaranteed>>
  25:        0x10e2592a5 - <<std[e853a6d0ec043b70]::thread::Builder>::spawn_unchecked_<rustc_interface[6b0baa6f0acee236]::util::run_in_thread_pool_with_globals<rustc_interface[6b0baa6f0acee236]::interface::run_compiler<core[e7c8723dd1d9fd02]::result::Result<(), rustc_errors[5974999511236221]::ErrorGuaranteed>, rustc_driver[c6bc39476a4ff69]::run_compiler::{closure#1}>::{closure#0}, core[e7c8723dd1d9fd02]::result::Result<(), rustc_errors[5974999511236221]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[e7c8723dd1d9fd02]::result::Result<(), rustc_errors[5974999511236221]::ErrorGuaranteed>>::{closure#1} as core[e7c8723dd1d9fd02]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  26:        0x10283ce87 - std::sys::unix::thread::Thread::new::thread_start::hb253bfeab5e611e1
  27:     0x7ff807a764e1 - __pthread_start

Regression

Regression in nightly-2018-12-30

Version

rustc 1.67.0-nightly (1eb62b123 2022-11-27)
binary: rustc
commit-hash: 1eb62b1235fd77200e6bd967d70e83c0f2497233
commit-date: 2022-11-27
host: x86_64-apple-darwin
release: 1.67.0-nightly
LLVM version: 15.0.4

[jruderman]

Same error message as #83950, but this one is self-contained and might be a separate bug.

[chenyukang]

@rustbot claim

[chenyukang]

@compiler-errors
how about make this bug to an error with diagonostic?

rust/compiler/rustc_resolve/src/imports.rs

Line 672 in cef44f5

span_bug!(import.span, "inconsistent resolution for an import");

Seems we don't have a chance to insert ambiguity_errors, because the use V is before the later use self::B::*;.

If we change code to this:

use self::A::*;
use self::B::*;
use V;

enum A {
    V
}
enum B {
    V
}
fn main() {}

It will be:

error[E0659]: `V` is ambiguous

rust/compiler/rustc_resolve/src/lib.rs

Line 1688 in cef44f5

if let Some((b2, kind)) = used_binding.ambiguity {

[cjgillot]

Could we register an AmbiguityError exactly in the place we ICE?

[chenyukang]

Yes, this is also a solution, and then we can report error in the same function report_errors.