ice: cannot convert ReLateParam to a region vid

[matthiaskrgr]

auto-reduced (treereduce-rust):

struct Test9;

impl Clone for Y {
    fn clone_from(&mut self, other: _) {
        *self = Test9;
    }
}

struct Struct;
trait Trait<T> {}

type Y = impl Trait<_>;

trait Qux {
    type A;

    const D: _ = 42;
}
impl Qux for Struct {}

fn map<T>() -> Qux<T> {
    None
}

const _: Option<_> = map(value);

original code

original:

// Needed for `type Y = impl Trait<_>` and `type B = _;`
#![feature(associated_type_defaults)]
#![feature(type_alias_impl_trait)]
// This test checks that it is not possible to enable global type
// inference by using the `_` type placeholder.

fn test() -> _ { 5 }
//~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types

fn test2() -> (_, _) { (5, 5) }
//~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types

static TEST3: _ = "test";
//~^ ERROR the placeholder `_` is not allowed within types on item signatures for static variables

static TEST4: _ = 145;
//~^ ERROR the placeholder `_` is not allowed within types on item signatures for static variables

static TEST5: (_, _) = (1, 2);
//~^ ERROR the placeholder `_` is not allowed within types on item signatures for static variables

fn test6(_: _) { }
//~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions

fn test6_b<T>(_: _, _: T) { }
//~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions

fn test6_c<T, K, L, A, B>(_: _, _: (T, K, L, A, B)) { }
//~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions

fn test7(x: _) { let _x: usize = x; }
//~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions

fn test8(_f: fn() -> _) { }
//~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
//~^^ ERROR the placeholder `_` is not allowed within types on item signatures for functions

struct Test9;

impl Test9 {
    fn test9(&self) -> _ { () }
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types

    fn test10(&self, _x : _) { }
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
}

fn test11(x: &usize) -> &_ {
//~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types
    &x
}

unsafe fn test12(x: *const usize) -> *const *const _ {
//~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types
    &x
}

impl Clone for Y {
    fn clone(&self) -> _ { Test9 }
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions

    fn clone_from(&mut self, other: _) { *self = Test9; }
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
}

struct Test10 {
    a: _,
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for structs
    b: (_, _),
}

pub fn main() {
    static A = 42;
    //~^ ERROR missing type for `static` item
    static B: _ = 42;
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for static variables
    static C: Option<_> = Some(42);
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for static variables
    fn fn_test() -> _ { 5 }
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types

    fn fn_test2() -> (_, _) { (5, 5) }
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types

    static FN_TEST3: _ = "test";
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for static variables

    static FN_TEST4: _ = 145;
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for static variables

    static FN_TEST5: (_, _) = (1, 2);
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for static variables

    fn fn_test6(_: _) { }
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions

    fn fn_test7(x: _) { let _x: usize = x; }
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions

    fn fn_test8(_f: fn() -> _) { }
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
    //~^^ ERROR the placeholder `_` is not allowed within types on item signatures for functions

    struct FnTest9;

    impl FnTest9 {
        fn fn_test9(&self) -> _ { () }
        //~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types

        fn fn_test10(&self, _x : _) { }
        //~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
    }

    impl Clone for FnTest9 {
        fn clone(&self) -> _ { FnTest9 }
        //~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions

        fn clone_from(&mut self, other: _) { *self = FnTest9; }
        //~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
    }

    struct FnTest10 {
        a: _,
        //~^ ERROR the placeholder `_` is not allowed within types on item signatures for structs
        b: (_, _),
    }

    fn D(_: _) -> (_, _) { panic!() }
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types
    //~| ERROR type annotations needed

    fn fn_test12(x: i32) -> (_, _) { (x, x) }
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types

    fn fn_test13(x: _) -> (i32, _) { (x, x) }
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types
}

trait T {
    fn method_test1(&self, x: _);
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
    fn method_test2(&self, x: _) -> _;
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
    fn method_test3(&self) -> _;
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
    fn assoc_fn_test1(x: _);
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
    fn assoc_fn_test2(x: _) -> _;
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
    fn assoc_fn_test3() -> _;
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for functions
}

struct BadStruct<_>(_);
//~^ ERROR expected identifier, found reserved identifier `_`
//~| ERROR the placeholder `_` is not allowed within types on item signatures for structs
trait BadTrait<_> {}
//~^ ERROR expected identifier, found reserved identifier `_`
impl BadTrait<_> for BadStruct<_> {}
//~^ ERROR the placeholder `_` is not allowed within types on item signatures for implementations

fn impl_trait() -> impl BadTrait<_> {
//~^ ERROR the placeholder `_` is not allowed within types on item signatures for opaque types
    unimplemented!()
}

struct BadStruct1<_, _>(_);
//~^ ERROR expected identifier, found reserved identifier `_`
//~| ERROR expected identifier, found reserved identifier `_`
//~| ERROR the name `_` is already used
//~| ERROR the placeholder `_` is not allowed within types on item signatures for structs
struct BadStruct2<_, T>(_, T);
//~^ ERROR expected identifier, found reserved identifier `_`
//~| ERROR the placeholder `_` is not allowed within types on item signatures for structs

type X = Box<_>;
//~^ ERROR the placeholder `_` is not allowed within types on item signatures for type aliases

struct Struct;
trait Trait<T> {}
impl Trait<usize> for Struct {}
type Y = impl Trait<_>;
//~^ ERROR the placeholder `_` is not allowed within types on item signatures for opaque types
fn foo() -> Y {
    Struct
}

trait Qux {
    type A;
    type B = _;
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for associated types
    const C: _;
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for associated constants
    const D: _ = 42;
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for associated constants
    // type E: _; // FIXME: make the parser propagate the existence of `B`
    type F: std::ops::Fn(_);
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for associated types
}
impl Qux for Struct {
    type A = _;
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for associated types
    type B = _;
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for associated types
    const C: _;
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for associated constants
    //~| ERROR associated constant in `impl` without body
    const D: _ = 42;
    //~^ ERROR the placeholder `_` is not allowed within types on item signatures for associated constants
}

fn map<T>(_: fn() -> Option<&'static T>) -> Qux<T> {
    None
}

fn value() -> Option<&'static _> {
//~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types
    Option::<&'static u8>::None
}

const _: Option<_> = map(value);
//~^ ERROR the placeholder `_` is not allowed within types on item signatures for constants

fn evens_squared(n: usize) -> _ {
//~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types
    (1..n).filter(|x| x % 2 == 0).map(|x| x * x)
}

const _: _ = (1..10).filter(|x| x % 2 == 0).map(|x| x * x);
//~^ ERROR the placeholder

Version information

rustc 1.76.0-nightly (e004adb55 2023-12-18)
binary: rustc
commit-hash: e004adb5561b724ac18f5b24584648ca4e42b6ad
commit-date: 2023-12-18
host: x86_64-unknown-linux-gnu
release: 1.76.0-nightly
LLVM version: 17.0.6

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

Program output

error[E0425]: cannot find value `value` in this scope
  --> /tmp/icemaker_global_tempdir.fSNNtQJdclF8/rustc_testrunner_tmpdir_reporting.O3o2lOsZKdS6/mvce.rs:25:26
   |
25 | const _: Option<_> = map(value);
   |                          ^^^^^ not found in this scope

error[E0658]: `impl Trait` in type aliases is unstable
  --> /tmp/icemaker_global_tempdir.fSNNtQJdclF8/rustc_testrunner_tmpdir_reporting.O3o2lOsZKdS6/mvce.rs:12:10
   |
12 | type Y = impl Trait<_>;
   |          ^^^^^^^^^^^^^
   |
   = note: see issue #63063 <https://github.com/rust-lang/rust/issues/63063> for more information
   = help: add `#![feature(type_alias_impl_trait)]` to the crate attributes to enable

error[E0601]: `main` function not found in crate `mvce`
  --> /tmp/icemaker_global_tempdir.fSNNtQJdclF8/rustc_testrunner_tmpdir_reporting.O3o2lOsZKdS6/mvce.rs:25:33
   |
25 | const _: Option<_> = map(value);
   |                                 ^ consider adding a `main` function to `/tmp/icemaker_global_tempdir.fSNNtQJdclF8/rustc_testrunner_tmpdir_reporting.O3o2lOsZKdS6/mvce.rs`

error[E0121]: the placeholder `_` is not allowed within types on item signatures for opaque types
  --> /tmp/icemaker_global_tempdir.fSNNtQJdclF8/rustc_testrunner_tmpdir_reporting.O3o2lOsZKdS6/mvce.rs:12:21
   |
12 | type Y = impl Trait<_>;
   |                     ^ not allowed in type signatures

warning: trait objects without an explicit `dyn` are deprecated
  --> /tmp/icemaker_global_tempdir.fSNNtQJdclF8/rustc_testrunner_tmpdir_reporting.O3o2lOsZKdS6/mvce.rs:21:16
   |
21 | fn map<T>() -> Qux<T> {
   |                ^^^^^^
   |
   = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
   = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
   = note: `#[warn(bare_trait_objects)]` on by default
help: use `dyn`
   |
21 | fn map<T>() -> dyn Qux<T> {
   |                +++

error[E0107]: trait takes 0 generic arguments but 1 generic argument was supplied
  --> /tmp/icemaker_global_tempdir.fSNNtQJdclF8/rustc_testrunner_tmpdir_reporting.O3o2lOsZKdS6/mvce.rs:21:16
   |
21 | fn map<T>() -> Qux<T> {
   |                ^^^ expected 0 generic arguments
   |
note: trait defined here, with 0 generic parameters
  --> /tmp/icemaker_global_tempdir.fSNNtQJdclF8/rustc_testrunner_tmpdir_reporting.O3o2lOsZKdS6/mvce.rs:14:7
   |
14 | trait Qux {
   |       ^^^
help: replace the generic bound with the associated type
   |
21 | fn map<T>() -> Qux<A = T> {
   |                    +++

error[E0191]: the value of the associated type `A` in `Qux` must be specified
  --> /tmp/icemaker_global_tempdir.fSNNtQJdclF8/rustc_testrunner_tmpdir_reporting.O3o2lOsZKdS6/mvce.rs:21:16
   |
15 |     type A;
   |     ------ `A` defined here
...
21 | fn map<T>() -> Qux<T> {
   |                ^^^^^^ associated type `A` must be specified

error[E0061]: this function takes 0 arguments but 1 argument was supplied
  --> /tmp/icemaker_global_tempdir.fSNNtQJdclF8/rustc_testrunner_tmpdir_reporting.O3o2lOsZKdS6/mvce.rs:25:22
   |
25 | const _: Option<_> = map(value);
   |                      ^^^ -----
   |                          |
   |                          unexpected argument
   |                          help: remove the extra argument
   |
note: function defined here
  --> /tmp/icemaker_global_tempdir.fSNNtQJdclF8/rustc_testrunner_tmpdir_reporting.O3o2lOsZKdS6/mvce.rs:21:4
   |
21 | fn map<T>() -> Qux<T> {
   |    ^^^

error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
 --> /tmp/icemaker_global_tempdir.fSNNtQJdclF8/rustc_testrunner_tmpdir_reporting.O3o2lOsZKdS6/mvce.rs:4:37
  |
4 |     fn clone_from(&mut self, other: _) {
  |                                     ^ not allowed in type signatures
  |
help: try replacing `_` with the type in the corresponding trait method signature
  |
4 |     fn clone_from(&mut self, other: &Y) {
  |                                     ~~

warning: unused variable: `other`
 --> /tmp/icemaker_global_tempdir.fSNNtQJdclF8/rustc_testrunner_tmpdir_reporting.O3o2lOsZKdS6/mvce.rs:4:30
  |
4 |     fn clone_from(&mut self, other: _) {
  |                              ^^^^^ help: if this is intentional, prefix it with an underscore: `_other`
  |
  = note: `#[warn(unused_variables)]` on by default

error: internal compiler error: compiler/rustc_borrowck/src/universal_regions.rs:823:36: cannot convert `ReLateParam(DefId(0:6 ~ mvce[6f81]::{impl#0}::clone_from), BrNamed(DefId(2:54203 ~ core[1a1d]::clone::Clone::clone_from::'_#1), '_))` to a region vid

thread 'rustc' panicked at /rustc/e004adb5561b724ac18f5b24584648ca4e42b6ad/compiler/rustc_errors/src/lib.rs:1119:75:
Box<dyn Any>
stack backtrace:
   0:     0x7fc78658aedc - std::backtrace_rs::backtrace::libunwind::trace::hf8d1e06f2dbfd1f2
                               at /rustc/e004adb5561b724ac18f5b24584648ca4e42b6ad/library/std/src/../../backtrace/src/backtrace/libunwind.rs:104:5
   1:     0x7fc78658aedc - std::backtrace_rs::backtrace::trace_unsynchronized::h944a853e00e0958c
                               at /rustc/e004adb5561b724ac18f5b24584648ca4e42b6ad/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7fc78658aedc - std::sys_common::backtrace::_print_fmt::h7873b3c31b9b61e3
                               at /rustc/e004adb5561b724ac18f5b24584648ca4e42b6ad/library/std/src/sys_common/backtrace.rs:68:5
   3:     0x7fc78658aedc - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h944f887c48f27d50
                               at /rustc/e004adb5561b724ac18f5b24584648ca4e42b6ad/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x7fc7865de040 - core::fmt::rt::Argument::fmt::h5846db7d079aab6c
                               at /rustc/e004adb5561b724ac18f5b24584648ca4e42b6ad/library/core/src/fmt/rt.rs:142:9
   5:     0x7fc7865de040 - core::fmt::write::h0fd1694961f0820b
                               at /rustc/e004adb5561b724ac18f5b24584648ca4e42b6ad/library/core/src/fmt/mod.rs:1120:17
   6:     0x7fc78657edef - std::io::Write::write_fmt::h2e32eec898b113ea
                               at /rustc/e004adb5561b724ac18f5b24584648ca4e42b6ad/library/std/src/io/mod.rs:1810:15
   7:     0x7fc78658acc4 - std::sys_common::backtrace::_print::h0f2767a50ffad96b
                               at /rustc/e004adb5561b724ac18f5b24584648ca4e42b6ad/library/std/src/sys_common/backtrace.rs:47:5
   8:     0x7fc78658acc4 - std::sys_common::backtrace::print::hc25db4529883a26a
                               at /rustc/e004adb5561b724ac18f5b24584648ca4e42b6ad/library/std/src/sys_common/backtrace.rs:34:9
   9:     0x7fc78658d987 - std::panicking::default_hook::{{closure}}::hd0792fb8614ae3f6
  10:     0x7fc78658d6ef - std::panicking::default_hook::h3663fb8da827b919
                               at /rustc/e004adb5561b724ac18f5b24584648ca4e42b6ad/library/std/src/panicking.rs:292:9
  11:     0x7fc789356650 - std[c5ba72f1f49ccbe8]::panicking::update_hook::<alloc[1f2919d2069b2ca0]::boxed::Box<rustc_driver_impl[1444d3f693ba8f9f]::install_ice_hook::{closure#0}>>::{closure#0}
  12:     0x7fc78658e0a6 - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::h52be504c6602c2c4
                               at /rustc/e004adb5561b724ac18f5b24584648ca4e42b6ad/library/alloc/src/boxed.rs:2029:9
  13:     0x7fc78658e0a6 - std::panicking::rust_panic_with_hook::h0f9b53de175fb9c2
                               at /rustc/e004adb5561b724ac18f5b24584648ca4e42b6ad/library/std/src/panicking.rs:783:13
  14:     0x7fc78938e374 - std[c5ba72f1f49ccbe8]::panicking::begin_panic::<rustc_errors[85bb5189461774fc]::ExplicitBug>::{closure#0}
  15:     0x7fc78938ac06 - std[c5ba72f1f49ccbe8]::sys_common::backtrace::__rust_end_short_backtrace::<std[c5ba72f1f49ccbe8]::panicking::begin_panic<rustc_errors[85bb5189461774fc]::ExplicitBug>::{closure#0}, !>
  16:     0x7fc78938a876 - std[c5ba72f1f49ccbe8]::panicking::begin_panic::<rustc_errors[85bb5189461774fc]::ExplicitBug>
  17:     0x7fc7893995f8 - <rustc_errors[85bb5189461774fc]::diagnostic_builder::Bug as rustc_errors[85bb5189461774fc]::diagnostic_builder::EmissionGuarantee>::diagnostic_builder_emit_producing_guarantee
  18:     0x7fc78977a8f5 - <rustc_errors[85bb5189461774fc]::DiagCtxt>::bug::<alloc[1f2919d2069b2ca0]::string::String>
  19:     0x7fc7898147db - rustc_middle[8fed8700d526b8a]::util::bug::opt_span_bug_fmt::<rustc_span[8207f921591536bc]::span_encoding::Span>::{closure#0}
  20:     0x7fc7897fe56a - rustc_middle[8fed8700d526b8a]::ty::context::tls::with_opt::<rustc_middle[8fed8700d526b8a]::util::bug::opt_span_bug_fmt<rustc_span[8207f921591536bc]::span_encoding::Span>::{closure#0}, !>::{closure#0}
  21:     0x7fc7897fe408 - rustc_middle[8fed8700d526b8a]::ty::context::tls::with_context_opt::<rustc_middle[8fed8700d526b8a]::ty::context::tls::with_opt<rustc_middle[8fed8700d526b8a]::util::bug::opt_span_bug_fmt<rustc_span[8207f921591536bc]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
  22:     0x7fc7876f73c0 - rustc_middle[8fed8700d526b8a]::util::bug::bug_fmt
  23:     0x7fc78b8888ad - <rustc_borrowck[9e744fb7478f1ce7]::universal_regions::UniversalRegionIndices>::fold_to_region_vids::<rustc_middle[8fed8700d526b8a]::ty::sty::Binder<rustc_middle[8fed8700d526b8a]::ty::sty::FnSig>>::{closure#0}.cold.0
  24:     0x7fc78a62a964 - <rustc_middle[8fed8700d526b8a]::ty::Ty as rustc_type_ir[2aac9198a7a08770]::fold::TypeSuperFoldable<rustc_middle[8fed8700d526b8a]::ty::context::TyCtxt>>::try_super_fold_with::<rustc_middle[8fed8700d526b8a]::ty::fold::RegionFolder>
  25:     0x7fc78a629aad - <&rustc_middle[8fed8700d526b8a]::ty::list::List<rustc_middle[8fed8700d526b8a]::ty::Ty> as rustc_type_ir[2aac9198a7a08770]::fold::TypeFoldable<rustc_middle[8fed8700d526b8a]::ty::context::TyCtxt>>::try_fold_with::<rustc_middle[8fed8700d526b8a]::ty::fold::RegionFolder>
  26:     0x7fc78b478bb1 - rustc_borrowck[9e744fb7478f1ce7]::do_mir_borrowck
  27:     0x7fc78b477319 - rustc_borrowck[9e744fb7478f1ce7]::mir_borrowck
  28:     0x7fc78b476db9 - rustc_query_impl[d8b4c006c93aa769]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[d8b4c006c93aa769]::query_impl::mir_borrowck::dynamic_query::{closure#2}::{closure#0}, rustc_middle[8fed8700d526b8a]::query::erase::Erased<[u8; 8usize]>>
  29:     0x7fc78a83ccc3 - rustc_query_system[17d0b5ace26db19a]::query::plumbing::try_execute_query::<rustc_query_impl[d8b4c006c93aa769]::DynamicConfig<rustc_query_system[17d0b5ace26db19a]::query::caches::VecCache<rustc_span[8207f921591536bc]::def_id::LocalDefId, rustc_middle[8fed8700d526b8a]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[d8b4c006c93aa769]::plumbing::QueryCtxt, false>
  30:     0x7fc78a83c890 - rustc_query_impl[d8b4c006c93aa769]::query_impl::mir_borrowck::get_query_non_incr::__rust_end_short_backtrace
  31:     0x7fc78ba0b7bc - rustc_middle[8fed8700d526b8a]::query::plumbing::query_get_at::<rustc_query_system[17d0b5ace26db19a]::query::caches::VecCache<rustc_span[8207f921591536bc]::def_id::LocalDefId, rustc_middle[8fed8700d526b8a]::query::erase::Erased<[u8; 8usize]>>>.llvm.13961986166402614303.cold.0
  32:     0x7fc7894a4b15 - <rustc_hir_analysis[48336eb585649c0a]::collect::type_of::opaque::TaitConstraintLocator>::check
  33:     0x7fc78948a6f5 - <rustc_hir_analysis[48336eb585649c0a]::collect::type_of::opaque::TaitConstraintLocator as rustc_hir[fc8afc23bda2c8cc]::intravisit::Visitor>::visit_impl_item
  34:     0x7fc78948a641 - <rustc_hir_analysis[48336eb585649c0a]::collect::type_of::opaque::TaitConstraintLocator as rustc_hir[fc8afc23bda2c8cc]::intravisit::Visitor>::visit_item
  35:     0x7fc78b5cf31b - rustc_hir_analysis[48336eb585649c0a]::collect::type_of::type_of_opaque
  36:     0x7fc78b5ceaf9 - rustc_query_impl[d8b4c006c93aa769]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[d8b4c006c93aa769]::query_impl::type_of_opaque::dynamic_query::{closure#2}::{closure#0}, rustc_middle[8fed8700d526b8a]::query::erase::Erased<[u8; 8usize]>>
  37:     0x7fc78a6849d4 - rustc_query_system[17d0b5ace26db19a]::query::plumbing::try_execute_query::<rustc_query_impl[d8b4c006c93aa769]::DynamicConfig<rustc_query_system[17d0b5ace26db19a]::query::caches::DefaultCache<rustc_span[8207f921591536bc]::def_id::DefId, rustc_middle[8fed8700d526b8a]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[d8b4c006c93aa769]::plumbing::QueryCtxt, false>
  38:     0x7fc78b645d1e - rustc_query_impl[d8b4c006c93aa769]::query_impl::type_of_opaque::get_query_non_incr::__rust_end_short_backtrace
  39:     0x7fc78a7e64c4 - rustc_middle[8fed8700d526b8a]::query::plumbing::query_get_at::<rustc_query_system[17d0b5ace26db19a]::query::caches::DefaultCache<rustc_span[8207f921591536bc]::def_id::DefId, rustc_middle[8fed8700d526b8a]::query::erase::Erased<[u8; 8usize]>>>
  40:     0x7fc788a08b7b - rustc_hir_analysis[48336eb585649c0a]::collect::type_of::type_of
  41:     0x7fc78a685ae6 - rustc_query_impl[d8b4c006c93aa769]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[d8b4c006c93aa769]::query_impl::type_of::dynamic_query::{closure#2}::{closure#0}, rustc_middle[8fed8700d526b8a]::query::erase::Erased<[u8; 8usize]>>
  42:     0x7fc78a6849d4 - rustc_query_system[17d0b5ace26db19a]::query::plumbing::try_execute_query::<rustc_query_impl[d8b4c006c93aa769]::DynamicConfig<rustc_query_system[17d0b5ace26db19a]::query::caches::DefaultCache<rustc_span[8207f921591536bc]::def_id::DefId, rustc_middle[8fed8700d526b8a]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[d8b4c006c93aa769]::plumbing::QueryCtxt, false>
  43:     0x7fc78a68459d - rustc_query_impl[d8b4c006c93aa769]::query_impl::type_of::get_query_non_incr::__rust_end_short_backtrace
  44:     0x7fc78aa70ac9 - rustc_middle[8fed8700d526b8a]::query::plumbing::query_get_at::<rustc_query_system[17d0b5ace26db19a]::query::caches::DefaultCache<rustc_span[8207f921591536bc]::def_id::DefId, rustc_middle[8fed8700d526b8a]::query::erase::Erased<[u8; 8usize]>>>
  45:     0x7fc78aa6cad9 - <rustc_privacy[db1ef3ffe8dcc2c1]::EmbargoVisitor as rustc_hir[fc8afc23bda2c8cc]::intravisit::Visitor>::visit_item
  46:     0x7fc78aa68b8a - <rustc_middle[8fed8700d526b8a]::hir::map::Map>::visit_all_item_likes_in_crate::<rustc_privacy[db1ef3ffe8dcc2c1]::EmbargoVisitor>
  47:     0x7fc78a642b50 - rustc_privacy[db1ef3ffe8dcc2c1]::effective_visibilities
  48:     0x7fc78a6429b5 - rustc_query_impl[d8b4c006c93aa769]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[d8b4c006c93aa769]::query_impl::effective_visibilities::dynamic_query::{closure#2}::{closure#0}, rustc_middle[8fed8700d526b8a]::query::erase::Erased<[u8; 8usize]>>
  49:     0x7fc78b2bb0f2 - rustc_query_system[17d0b5ace26db19a]::query::plumbing::try_execute_query::<rustc_query_impl[d8b4c006c93aa769]::DynamicConfig<rustc_query_system[17d0b5ace26db19a]::query::caches::SingleCache<rustc_middle[8fed8700d526b8a]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[d8b4c006c93aa769]::plumbing::QueryCtxt, false>
  50:     0x7fc78b2bba06 - rustc_query_impl[d8b4c006c93aa769]::query_impl::effective_visibilities::get_query_non_incr::__rust_end_short_backtrace
  51:     0x7fc7896424e9 - rustc_infer[2ae1df4046e74a8]::traits::error_reporting::report_object_safety_error
  52:     0x7fc789e945d1 - <rustc_infer[2ae1df4046e74a8]::infer::error_reporting::TypeErrCtxt as rustc_trait_selection[21155bdcdc3017e2]::traits::error_reporting::type_err_ctxt_ext::TypeErrCtxtExt>::report_selection_error
  53:     0x7fc789ebd221 - <rustc_infer[2ae1df4046e74a8]::infer::error_reporting::TypeErrCtxt as rustc_trait_selection[21155bdcdc3017e2]::traits::error_reporting::type_err_ctxt_ext::InferCtxtPrivExt>::report_fulfillment_error
  54:     0x7fc789e918d7 - <rustc_infer[2ae1df4046e74a8]::infer::error_reporting::TypeErrCtxt as rustc_trait_selection[21155bdcdc3017e2]::traits::error_reporting::type_err_ctxt_ext::TypeErrCtxtExt>::report_fulfillment_errors
  55:     0x7fc78b049b05 - <rustc_hir_typeck[efc20ad080163a56]::fn_ctxt::FnCtxt>::type_inference_fallback
  56:     0x7fc7895763f5 - rustc_hir_typeck[efc20ad080163a56]::diagnostic_only_typeck
  57:     0x7fc789bab127 - rustc_query_impl[d8b4c006c93aa769]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[d8b4c006c93aa769]::query_impl::diagnostic_only_typeck::dynamic_query::{closure#2}::{closure#0}, rustc_middle[8fed8700d526b8a]::query::erase::Erased<[u8; 8usize]>>
  58:     0x7fc78a83ccc3 - rustc_query_system[17d0b5ace26db19a]::query::plumbing::try_execute_query::<rustc_query_impl[d8b4c006c93aa769]::DynamicConfig<rustc_query_system[17d0b5ace26db19a]::query::caches::VecCache<rustc_span[8207f921591536bc]::def_id::LocalDefId, rustc_middle[8fed8700d526b8a]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[d8b4c006c93aa769]::plumbing::QueryCtxt, false>
  59:     0x7fc789bb7080 - rustc_query_impl[d8b4c006c93aa769]::query_impl::diagnostic_only_typeck::get_query_non_incr::__rust_end_short_backtrace
  60:     0x7fc78ba0b7bc - rustc_middle[8fed8700d526b8a]::query::plumbing::query_get_at::<rustc_query_system[17d0b5ace26db19a]::query::caches::VecCache<rustc_span[8207f921591536bc]::def_id::LocalDefId, rustc_middle[8fed8700d526b8a]::query::erase::Erased<[u8; 8usize]>>>.llvm.13961986166402614303.cold.0
  61:     0x7fc78948a9dc - rustc_hir_analysis[48336eb585649c0a]::collect::type_of::infer_placeholder_type
  62:     0x7fc788a090df - rustc_hir_analysis[48336eb585649c0a]::collect::type_of::type_of
  63:     0x7fc78a685ae6 - rustc_query_impl[d8b4c006c93aa769]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[d8b4c006c93aa769]::query_impl::type_of::dynamic_query::{closure#2}::{closure#0}, rustc_middle[8fed8700d526b8a]::query::erase::Erased<[u8; 8usize]>>
  64:     0x7fc78a6849d4 - rustc_query_system[17d0b5ace26db19a]::query::plumbing::try_execute_query::<rustc_query_impl[d8b4c006c93aa769]::DynamicConfig<rustc_query_system[17d0b5ace26db19a]::query::caches::DefaultCache<rustc_span[8207f921591536bc]::def_id::DefId, rustc_middle[8fed8700d526b8a]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[d8b4c006c93aa769]::plumbing::QueryCtxt, false>
  65:     0x7fc78a68459d - rustc_query_impl[d8b4c006c93aa769]::query_impl::type_of::get_query_non_incr::__rust_end_short_backtrace
  66:     0x7fc78a8f7fa2 - <rustc_hir_analysis[48336eb585649c0a]::collect::CollectItemTypesVisitor as rustc_hir[fc8afc23bda2c8cc]::intravisit::Visitor>::visit_item
  67:     0x7fc78a8f7329 - rustc_hir_analysis[48336eb585649c0a]::collect::collect_mod_item_types
  68:     0x7fc78a8f72b7 - rustc_query_impl[d8b4c006c93aa769]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[d8b4c006c93aa769]::query_impl::collect_mod_item_types::dynamic_query::{closure#2}::{closure#0}, rustc_middle[8fed8700d526b8a]::query::erase::Erased<[u8; 0usize]>>
  69:     0x7fc78b1af07b - rustc_query_system[17d0b5ace26db19a]::query::plumbing::try_execute_query::<rustc_query_impl[d8b4c006c93aa769]::DynamicConfig<rustc_query_system[17d0b5ace26db19a]::query::caches::DefaultCache<rustc_span[8207f921591536bc]::def_id::LocalModDefId, rustc_middle[8fed8700d526b8a]::query::erase::Erased<[u8; 0usize]>>, false, false, false>, rustc_query_impl[d8b4c006c93aa769]::plumbing::QueryCtxt, false>
  70:     0x7fc78b1aeb97 - rustc_query_impl[d8b4c006c93aa769]::query_impl::collect_mod_item_types::get_query_non_incr::__rust_end_short_backtrace
  71:     0x7fc78ae312df - rustc_hir_analysis[48336eb585649c0a]::check_crate
  72:     0x7fc78af6cb17 - rustc_interface[b6a357093a72c36b]::passes::analysis
  73:     0x7fc78af6c75d - rustc_query_impl[d8b4c006c93aa769]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[d8b4c006c93aa769]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[8fed8700d526b8a]::query::erase::Erased<[u8; 1usize]>>
  74:     0x7fc78b5a8db2 - rustc_query_system[17d0b5ace26db19a]::query::plumbing::try_execute_query::<rustc_query_impl[d8b4c006c93aa769]::DynamicConfig<rustc_query_system[17d0b5ace26db19a]::query::caches::SingleCache<rustc_middle[8fed8700d526b8a]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[d8b4c006c93aa769]::plumbing::QueryCtxt, false>
  75:     0x7fc78b5a8bb9 - rustc_query_impl[d8b4c006c93aa769]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  76:     0x7fc78b63ddf1 - rustc_interface[b6a357093a72c36b]::interface::run_compiler::<core[1a1dce668ca699c0]::result::Result<(), rustc_span[8207f921591536bc]::ErrorGuaranteed>, rustc_driver_impl[1444d3f693ba8f9f]::run_compiler::{closure#0}>::{closure#0}
  77:     0x7fc78b5b5020 - std[c5ba72f1f49ccbe8]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[b6a357093a72c36b]::util::run_in_thread_with_globals<rustc_interface[b6a357093a72c36b]::util::run_in_thread_pool_with_globals<rustc_interface[b6a357093a72c36b]::interface::run_compiler<core[1a1dce668ca699c0]::result::Result<(), rustc_span[8207f921591536bc]::ErrorGuaranteed>, rustc_driver_impl[1444d3f693ba8f9f]::run_compiler::{closure#0}>::{closure#0}, core[1a1dce668ca699c0]::result::Result<(), rustc_span[8207f921591536bc]::ErrorGuaranteed>>::{closure#0}, core[1a1dce668ca699c0]::result::Result<(), rustc_span[8207f921591536bc]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[1a1dce668ca699c0]::result::Result<(), rustc_span[8207f921591536bc]::ErrorGuaranteed>>
  78:     0x7fc78b5b4e4f - <<std[c5ba72f1f49ccbe8]::thread::Builder>::spawn_unchecked_<rustc_interface[b6a357093a72c36b]::util::run_in_thread_with_globals<rustc_interface[b6a357093a72c36b]::util::run_in_thread_pool_with_globals<rustc_interface[b6a357093a72c36b]::interface::run_compiler<core[1a1dce668ca699c0]::result::Result<(), rustc_span[8207f921591536bc]::ErrorGuaranteed>, rustc_driver_impl[1444d3f693ba8f9f]::run_compiler::{closure#0}>::{closure#0}, core[1a1dce668ca699c0]::result::Result<(), rustc_span[8207f921591536bc]::ErrorGuaranteed>>::{closure#0}, core[1a1dce668ca699c0]::result::Result<(), rustc_span[8207f921591536bc]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[1a1dce668ca699c0]::result::Result<(), rustc_span[8207f921591536bc]::ErrorGuaranteed>>::{closure#1} as core[1a1dce668ca699c0]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  79:     0x7fc786597ef5 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h605802586f69a65d
                               at /rustc/e004adb5561b724ac18f5b24584648ca4e42b6ad/library/alloc/src/boxed.rs:2015:9
  80:     0x7fc786597ef5 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::hde1bcd609c096275
                               at /rustc/e004adb5561b724ac18f5b24584648ca4e42b6ad/library/alloc/src/boxed.rs:2015:9
  81:     0x7fc786597ef5 - std::sys::unix::thread::Thread::new::thread_start::h972b401527bc30fd
                               at /rustc/e004adb5561b724ac18f5b24584648ca4e42b6ad/library/std/src/sys/unix/thread.rs:108:17
  82:     0x7fc7863849eb - <unknown>
  83:     0x7fc7864087cc - <unknown>
  84:                0x0 - <unknown>

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 1.76.0-nightly (e004adb55 2023-12-18) running on x86_64-unknown-linux-gnu

query stack during panic:
#0 [mir_borrowck] borrow-checking `<impl at /tmp/icemaker_global_tempdir.fSNNtQJdclF8/rustc_testrunner_tmpdir_reporting.O3o2lOsZKdS6/mvce.rs:3:1: 3:17>::clone_from`
#1 [type_of_opaque] computing type of opaque `Y::{opaque#0}`
#2 [type_of] computing type of `Y::{opaque#0}`
#3 [effective_visibilities] checking effective visibilities
#4 [diagnostic_only_typeck] type-checking `_`
#5 [type_of] computing type of `_`
#6 [collect_mod_item_types] collecting item types in top-level module
#7 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to 9 previous errors; 2 warnings emitted

Some errors have detailed explanations: E0061, E0107, E0121, E0191, E0425, E0601, E0658.
For more information about an error, try `rustc --explain E0061`.

[matthiaskrgr]

Regression in nightly-2023-10-31
Regression in 236ac91
Regression in rust-lang-ci@33ef793
=> #117132 ping @estebank

[estebank]

I can no longer reproduce. @matthiaskrgr feel free to reopen if I'm missing something.