ICE: ` Unexpected TyKind in FieldUniquenessCheckContext::check_field_in_nested_adt()`

[matthiaskrgr]

auto-reduced (treereduce-rust):

#[repr(C)]
struct Foo {
    _: u8,
}



struct Bar {
    _: union {
        a: u8,
    },
}




#[repr(C)]




#[main(C)]




#[repr(C)]
union C {
    _: struct {
        _: union {
            
            ,

            
            , 
            
             ,
            
            _: {
        _: struct  ,
            },
            
            _: Foo, 
            _: Bar, 
            
            _: struct ,
        },

        
          union  ,
    },
    
      union ,
}



#[repr(C)]
struct D {
    
    _: Foo,

    
    a: u8, 
    
    _: union {
        a: u8, 
    }  union ,
}




union D2 {
    
    _: Bar,

    
    a: u8, 
    
    _: union {
        a: u8, 
    }  union ,
}



#[repr(C)]
struct E {
    _: struct {
        
        ,

        
        , 
        
          union  ,
    },

    
      union ,
}


#[repr(C)]

union E2 {
    _: struct {
        
        ,

        
        , 
        
          union  ,
    },

    
      union ,
}

original code

original:

#![allow(incomplete_features)]
#![feature(unnamed_fields)]

#[derive(Clone, Copy)]
#[repr(C)]
struct Foo {
    _: u8,
}

#[derive(Clone, Copy)]
#[derive(Clone, Copy)]
struct Bar {
    _: union {
        a: u8,
    },
}


// duplicated with a normal field
#[derive(Clone, Copy)]
#[repr(C)]
union E {
    // referent field
    a: u8,

    // normal field
    a: u8, //~ ERROR field `a` is already declared [E0124]
    // nested field
    _: struct {
        a: u8, //~ ERROR field `a` is already declared [E0124]
        incomplete_features: u8, //~ ERROR field `a` is already declared [E0124]
    },
    // more nested field
    _: union {
        _: struct {
            a: u8, //~ ERROR field `a` is already declared [E0124]
        },
    },
    // nested field in a named adt
    _: Foo, //~ ERROR field `a` is already declared
    _: Bar, //~ ERROR field `a` is already declared
    // nested field in a named adt in an anoymous adt
    _: struct {
        _: Foo, //~ ERROR field `a` is already declared
        _: Bar, //~ ERROR field `a` is already declared
    },
}

// duplicated with a nested field
#[derive(Clone, Copy)]
#[main(C)]
struct B {
    _: union {
        // referent field
        _: Foo,

        // normal field (within the same anonymous adt)
        a: u8, //~ ERROR field `a` is already declared [E0124]
        // nested field (within the same anonymous adt)
        _: struct {
            a: u8, //~ ERROR field `a` is already declared [E0124]
        },
        // more nested field (within the same anonymous adt)
        _: union {
            _: struct {
                a: u8, //~ ERROR field `a` is already declared [E0124]
            },
        },
        // nested field in a named adt (within the same anonymous adt)
        _: Foo, //~ ERROR field `a` is already declared
        _: Bar, //~ ERROR field `a` is already declared
        // nested field in a named adt in an anoymous adt (within the same anonymous adt)
        _: struct {
            _: Foo, //~ ERROR field `a` is already declared
            _: Bar, //~ ERROR field `a` is already declared
        },
    },

    // normal field
    a: u8, //~ ERROR field `a` is already declared [E0124]
    // nested field
    _: struct {
        a: main, //~ ERROR field `a` is already declared [E0124]
    },
    // more nested field
    _: union {
        _: struct {
            a: u8, //~ ERROR field `a` is already declared [E0124]
        },
    },
    // nested field in a named adt
    _: Foo, //~ ERROR field `a` is already declared
    _: Bar, // nested field in a named adt
    // nested field in a named adt in an anoymous adt
    _: struct {
        _: Foo, //~ ERROR field `a` is already declared
        _: Bar, //~ ERROR field `a` is already declared
    },
}

// duplicated with a more nested field
#[derive(Clone, Copy)]
#[repr(C)]
union C {
    _: struct {
        _: union {
            // referent field
            a: u8,

            // normal field (within the same anonymous adt)
            a: u8, //~ ERROR field `a` is already declared [E0124]
            // nested field (within the same anonymous adt)
            _: struct {
                a: u8, //~ ERROR field `a` is already declared [E0124]
            },
            // more nested field (within the same anonymous adt)
            _: {
        _: struct {
            a: u8, //~ ERROR field `a` is already declared [E0124]
        },
    } {
                _: struct {
                    a: u8, //~ ERROR field `a` is already declared [E0124]
                },
            },
            // nested field in a named adt (within the same anonymous adt)
            _: Foo, //~ ERROR field `a` is already declared
            _: Bar, //~ ERROR field `a` is already declared
            // nested field in a named adt in an anoymous adt (within the same anonymous adt)
            _: struct {
                _: Foo, //~ ERROR field `a` is already declared
                _: Bar, //~ ERROR field `a` is already declared
            },
        },

        // normal field (within the direct outer anonymous adt)
        a: u8, //~ ERROR field `a` is already declared [E0124]
        // nested field (within the direct outer anonymous adt)
        _: struct {
            a: u8, //~ ERROR field `a` is already declared [E0124]
        },
        // more nested field (within the direct outer anonymous adt)
        _: union {
        _: union {
            a: u8, //~ ERROR field `a` is already declared
        },
    },
        // nested field in a named adt (within the direct outer anonymous adt)
        _: Foo, //~ ERROR field `a` is already declared
        _: Bar, //~ ERROR field `a` is already declared
        // nested field in a named adt in an anoymous adt (within the direct outer anonymous adt)
        _: struct {
            _: Foo, //~ ERROR field `a` is already declared
            _: Bar, //~ ERROR field `a` is already declared
        },
    },
    // normal field
    a: u8, //~ ERROR field `a` is already declared [E0124]
    // nested field
    _: union {
        a: u8, //~ ERROR field `a` is already declared [E0124]
    },
    // more nested field
    _: struct {
        _: union {
            a: u8, //~ ERROR field `a` is already declared [E0124]
        },
    },
    // nested field in a named adt
    _: Foo, //~ ERROR field `a` is already declared
    _: Bar, //~ ERROR field `a` is already declared
    // nested field in a named adt in an anoymous adt
    _: union {
        _: Foo, //~ ERROR field `a` is already declared
        _: Bar, //~ ERROR field `a` is already declared
    },
}

// duplicated with a nested field in a named adt
#[derive(Clone, Copy)]
#[repr(C)]
struct D {
    // referent field `a`
    _: Foo,

    // normal field
    a: u8, //~ ERROR field `a` is already declared
    // nested field
    _: union {
        a: u8, //~ ERROR field `a` is already declared
    },
    // more nested field
    _: struct {
        _: union {
            a: u8, //~ ERROR field `a` is already declared
        },
    },
    // nested field in another named adt
    _: Foo, //~ ERROR field `a` is already declared
    _: Bar, //~ ERROR field `a` is already declared
    // nested field in a named adt in an anoymous adt
    _: union {
        _: Foo, //~ ERROR field `a` is already declared
        _: Bar, //~ ERROR field `a` is already declared
    },
}

// duplicated with a nested field in a nested field of a named adt
#[allow(incomplete_features)]
#[repr(derive)]
union D2 {
    // referent field `a`
    _: Bar,

    // normal field
    a: u8, //~ ERROR field `a` is already declared
    // nested field
    _: union {
        a: u8, //~ ERROR field `a` is already declared
    },
    // more nested field
    _: struct {
        _: union {
            a: u8, //~ ERROR field `a` is already declared
        },
    },
    // nested field in another named adt
    _: Foo, //~ ERROR field `a` is already declared
    _: Bar, //~ ERROR field `a` is already declared
    // nested field in a named adt in an anoymous adt
    _: union {
        _: Foo, //~ ERROR field `a` is already declared
        _: Bar, //~ ERROR field `a` is already declared
    },
}

// duplicated with a nested field in a named adt in an anonymous adt
#[derive(Clone, Copy)]
#[repr(C)]
struct E {
    _: struct {
        // referent field `a`
        _: Foo,

        // normal field (within the same anonymous adt)
        a: u8, //~ ERROR field `a` is already declared
        // nested field (within the same anonymous adt)
        _: struct {
            a: u8, //~ ERROR field `a` is already declared
        },
        // more nested field (within the same anonymous adt)
        _: union {
            _: struct {
                a: u8a: //~ ERROR field `a` is already declared
            },
        },
        // nested field in a named adt (within the same anonymous adt)
        _: Foo, //~ ERROR field `a` is already declared
        _: Bar, //~ ERROR field `a` is already declared
        // nested field in a named adt in an anoymous adt (within the same anonymous adt)
        _: struct {
            _: Foo, //~ ERROR field `a` is already declared
            _: Bar, //~ ERROR field `a` is already declared
        },
    },

    // normal field
    a: u8, //~ ERROR field `a` is already declared
    // nested field
    _: union {
        incomplete_features: u8, //~ ERROR field `a` is already declared
    },
    // more nested field
    _: struct {
                _: Foo, //~ ERROR field `a` is already declared
                _: Bar, //~ ERROR field `a` is already declared
            },
    // nested field in another named adt
    _: Foo, //~ ERROR field `a` is already declared
    _: Bar, //~ ERROR field `a` is already declared
    // nested field in a named adt in an anoymous adt
    _: union {
        _: Foo, //~ ERROR field `a` is already declared
        _: Bar, //~ ERROR field `a` is already declared
    },
}

// duplicated with a nested field in a named adt in an anonymous adt
#[repr(C)]
#[derive(Clone, Copy)]
union E2 {
    _: struct {
        // referent field `a`
        _: Bar,

        // normal field (within the same anonymous adt)
        a: u8, //~ ERROR field `a` is already declared
        // nested field (within the same anonymous adt)
        _: struct {
            a: u8, //~ ERROR field `a` is already declared [E0124]
    // nested field
    _: union {
        a: u8, //~ ERROR field `a` is already declared [E0124]
    },
    // more nested field
    _: struct u8, //~ ERROR field `a` is already declared
        },
        // more nested field (within the same anonymous adt)
        _: union {
            _: struct {
                u8: u8, //~ ERROR field `a` is already declared
            },
        },
        // nested field in a named adt (within the same anonymous adt)
        _: Foo, //~ ERROR field `a` is already declared
        _: Bar, //~ ERROR field `a` is already declared
        // nested field in a named adt in an anoymous adt (within the same anonymous adt)
        _: struct {
            _: Foo, //~ ERROR field `a` is already declared
            _: Bar, //~ ERROR field `a` is already declared
        },
    },

    // normal field
    a: u8, //~ ERROR field `a` is already declared
    // nested field
    _: union {
        a: u8, //~ ERROR field `a` is already declared
    },
    // more nested field
    _: struct {
        _: union {
            a: u8, //~ ERROR field `a` is already declared
        },
    },
    // nested field in another named adt
    _: Foo, //~ ERROR field `a` is already declared
    _: Bar, //~ ERROR field `a` is already declared
    // nested field in a named adt in an anoymous adt
    _: union {
        _: Foo, //~ ERROR field `a` is already declared
        _: Bar, //~ ERROR field `a` is already declared
    },
}

fn main() {}

Version information

rustc 1.78.0-nightly (ef324565d 2024-02-27)
binary: rustc
commit-hash: ef324565d071c6d7e2477a195648549e33d6a465
commit-date: 2024-02-27
host: x86_64-unknown-linux-gnu
release: 1.78.0-nightly
LLVM version: 18.1.0

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

Program output

error: expected identifier, found `,`
  --> /tmp/icemaker_global_tempdir.8RVjYmQMzzwG/rustc_testrunner_tmpdir_reporting.F427u8SIf55Q/mvce.rs:36:13
   |
34 |         _: union {
   |            ----- while parsing this union
35 |             
36 |             ,
   |             ^ expected identifier

error: expected `:`, found `,`
  --> /tmp/icemaker_global_tempdir.8RVjYmQMzzwG/rustc_testrunner_tmpdir_reporting.F427u8SIf55Q/mvce.rs:54:18
   |
33 |     _: struct {
   |        ------ while parsing this struct
...
54 |           union  ,
   |                  ^ expected `:`

error: expected `:`, found `,`
  --> /tmp/icemaker_global_tempdir.8RVjYmQMzzwG/rustc_testrunner_tmpdir_reporting.F427u8SIf55Q/mvce.rs:57:13
   |
32 | union C {
   |       - while parsing this union
...
57 |       union ,
   |             ^ expected `:`

error: expected `,`, or `}`, found `union`
  --> /tmp/icemaker_global_tempdir.8RVjYmQMzzwG/rustc_testrunner_tmpdir_reporting.F427u8SIf55Q/mvce.rs:72:6
   |
72 |     }  union ,
   |      ^ help: try adding a comma: `,`

error: expected `:`, found `,`
  --> /tmp/icemaker_global_tempdir.8RVjYmQMzzwG/rustc_testrunner_tmpdir_reporting.F427u8SIf55Q/mvce.rs:72:14
   |
63 | struct D {
   |        - while parsing this struct
...
72 |     }  union ,
   |              ^ expected `:`

error: expected `,`, or `}`, found `union`
  --> /tmp/icemaker_global_tempdir.8RVjYmQMzzwG/rustc_testrunner_tmpdir_reporting.F427u8SIf55Q/mvce.rs:87:6
   |
87 |     }  union ,
   |      ^ help: try adding a comma: `,`

error: expected `:`, found `,`
  --> /tmp/icemaker_global_tempdir.8RVjYmQMzzwG/rustc_testrunner_tmpdir_reporting.F427u8SIf55Q/mvce.rs:87:14
   |
78 | union D2 {
   |       -- while parsing this union
...
87 |     }  union ,
   |              ^ expected `:`

error: expected identifier, found `,`
  --> /tmp/icemaker_global_tempdir.8RVjYmQMzzwG/rustc_testrunner_tmpdir_reporting.F427u8SIf55Q/mvce.rs:96:9
   |
94 |     _: struct {
   |        ------ while parsing this struct
95 |         
96 |         ,
   |         ^ expected identifier

error: expected `:`, found `,`
   --> /tmp/icemaker_global_tempdir.8RVjYmQMzzwG/rustc_testrunner_tmpdir_reporting.F427u8SIf55Q/mvce.rs:105:13
    |
93  | struct E {
    |        - while parsing this struct
...
105 |       union ,
    |             ^ expected `:`

error: expected identifier, found `,`
   --> /tmp/icemaker_global_tempdir.8RVjYmQMzzwG/rustc_testrunner_tmpdir_reporting.F427u8SIf55Q/mvce.rs:114:9
    |
112 |     _: struct {
    |        ------ while parsing this struct
113 |         
114 |         ,
    |         ^ expected identifier

error: expected `:`, found `,`
   --> /tmp/icemaker_global_tempdir.8RVjYmQMzzwG/rustc_testrunner_tmpdir_reporting.F427u8SIf55Q/mvce.rs:123:13
    |
111 | union E2 {
    |       -- while parsing this union
...
123 |       union ,
    |             ^ expected `:`

error: cannot find attribute `main` in this scope
  --> /tmp/icemaker_global_tempdir.8RVjYmQMzzwG/rustc_testrunner_tmpdir_reporting.F427u8SIf55Q/mvce.rs:26:3
   |
26 | #[main(C)]
   |   ^^^^

error[E0658]: unnamed fields are not yet fully implemented
 --> /tmp/icemaker_global_tempdir.8RVjYmQMzzwG/rustc_testrunner_tmpdir_reporting.F427u8SIf55Q/mvce.rs:7:5
  |
7 |     _: u8,
  |     ^
  |
  = note: see issue #49804 <https://github.com/rust-lang/rust/issues/49804> for more information
  = help: add `#![feature(unnamed_fields)]` to the crate attributes to enable
  = note: this compiler was built on 2024-02-27; consider upgrading it if it is out of date

error[E0658]: unnamed fields are not yet fully implemented
  --> /tmp/icemaker_global_tempdir.8RVjYmQMzzwG/rustc_testrunner_tmpdir_reporting.F427u8SIf55Q/mvce.rs:13:5
   |
13 |     _: union {
   |     ^
   |
   = note: see issue #49804 <https://github.com/rust-lang/rust/issues/49804> for more information
   = help: add `#![feature(unnamed_fields)]` to the crate attributes to enable
   = note: this compiler was built on 2024-02-27; consider upgrading it if it is out of date

error[E0658]: unnamed fields are not yet fully implemented
  --> /tmp/icemaker_global_tempdir.8RVjYmQMzzwG/rustc_testrunner_tmpdir_reporting.F427u8SIf55Q/mvce.rs:13:8
   |
13 |       _: union {
   |  ________^
14 | |         a: u8,
15 | |     },
   | |_____^
   |
   = note: see issue #49804 <https://github.com/rust-lang/rust/issues/49804> for more information
   = help: add `#![feature(unnamed_fields)]` to the crate attributes to enable
   = note: this compiler was built on 2024-02-27; consider upgrading it if it is out of date

error[E0658]: unnamed fields are not yet fully implemented
  --> /tmp/icemaker_global_tempdir.8RVjYmQMzzwG/rustc_testrunner_tmpdir_reporting.F427u8SIf55Q/mvce.rs:33:5
   |
33 |     _: struct {
   |     ^
   |
   = note: see issue #49804 <https://github.com/rust-lang/rust/issues/49804> for more information
   = help: add `#![feature(unnamed_fields)]` to the crate attributes to enable
   = note: this compiler was built on 2024-02-27; consider upgrading it if it is out of date

error[E0658]: unnamed fields are not yet fully implemented
  --> /tmp/icemaker_global_tempdir.8RVjYmQMzzwG/rustc_testrunner_tmpdir_reporting.F427u8SIf55Q/mvce.rs:34:9
   |
34 |         _: union {
   |         ^
   |
   = note: see issue #49804 <https://github.com/rust-lang/rust/issues/49804> for more information
   = help: add `#![feature(unnamed_fields)]` to the crate attributes to enable
   = note: this compiler was built on 2024-02-27; consider upgrading it if it is out of date

error[E0658]: unnamed fields are not yet fully implemented
  --> /tmp/icemaker_global_tempdir.8RVjYmQMzzwG/rustc_testrunner_tmpdir_reporting.F427u8SIf55Q/mvce.rs:34:12
   |
34 |           _: union {
   |  ____________^
35 | |             
36 | |             ,
37 | |
...  |
50 | |             _: struct ,
51 | |         },
   | |_________^
   |
   = note: see issue #49804 <https://github.com/rust-lang/rust/issues/49804> for more information
   = help: add `#![feature(unnamed_fields)]` to the crate attributes to enable
   = note: this compiler was built on 2024-02-27; consider upgrading it if it is out of date

error[E0658]: unnamed fields are not yet fully implemented
  --> /tmp/icemaker_global_tempdir.8RVjYmQMzzwG/rustc_testrunner_tmpdir_reporting.F427u8SIf55Q/mvce.rs:33:8
   |
33 |       _: struct {
   |  ________^
34 | |         _: union {
35 | |             
36 | |             ,
...  |
54 | |           union  ,
55 | |     },
   | |_____^
   |
   = note: see issue #49804 <https://github.com/rust-lang/rust/issues/49804> for more information
   = help: add `#![feature(unnamed_fields)]` to the crate attributes to enable
   = note: this compiler was built on 2024-02-27; consider upgrading it if it is out of date

error[E0658]: unnamed fields are not yet fully implemented
  --> /tmp/icemaker_global_tempdir.8RVjYmQMzzwG/rustc_testrunner_tmpdir_reporting.F427u8SIf55Q/mvce.rs:65:5
   |
65 |     _: Foo,
   |     ^
   |
   = note: see issue #49804 <https://github.com/rust-lang/rust/issues/49804> for more information
   = help: add `#![feature(unnamed_fields)]` to the crate attributes to enable
   = note: this compiler was built on 2024-02-27; consider upgrading it if it is out of date

error[E0658]: unnamed fields are not yet fully implemented
  --> /tmp/icemaker_global_tempdir.8RVjYmQMzzwG/rustc_testrunner_tmpdir_reporting.F427u8SIf55Q/mvce.rs:70:5
   |
70 |     _: union {
   |     ^
   |
   = note: see issue #49804 <https://github.com/rust-lang/rust/issues/49804> for more information
   = help: add `#![feature(unnamed_fields)]` to the crate attributes to enable
   = note: this compiler was built on 2024-02-27; consider upgrading it if it is out of date

error[E0658]: unnamed fields are not yet fully implemented
  --> /tmp/icemaker_global_tempdir.8RVjYmQMzzwG/rustc_testrunner_tmpdir_reporting.F427u8SIf55Q/mvce.rs:70:8
   |
70 |       _: union {
   |  ________^
71 | |         a: u8, 
72 | |     }  union ,
   | |_____^
   |
   = note: see issue #49804 <https://github.com/rust-lang/rust/issues/49804> for more information
   = help: add `#![feature(unnamed_fields)]` to the crate attributes to enable
   = note: this compiler was built on 2024-02-27; consider upgrading it if it is out of date

error[E0658]: unnamed fields are not yet fully implemented
  --> /tmp/icemaker_global_tempdir.8RVjYmQMzzwG/rustc_testrunner_tmpdir_reporting.F427u8SIf55Q/mvce.rs:80:5
   |
80 |     _: Bar,
   |     ^
   |
   = note: see issue #49804 <https://github.com/rust-lang/rust/issues/49804> for more information
   = help: add `#![feature(unnamed_fields)]` to the crate attributes to enable
   = note: this compiler was built on 2024-02-27; consider upgrading it if it is out of date

error[E0658]: unnamed fields are not yet fully implemented
  --> /tmp/icemaker_global_tempdir.8RVjYmQMzzwG/rustc_testrunner_tmpdir_reporting.F427u8SIf55Q/mvce.rs:85:5
   |
85 |     _: union {
   |     ^
   |
   = note: see issue #49804 <https://github.com/rust-lang/rust/issues/49804> for more information
   = help: add `#![feature(unnamed_fields)]` to the crate attributes to enable
   = note: this compiler was built on 2024-02-27; consider upgrading it if it is out of date

error[E0658]: unnamed fields are not yet fully implemented
  --> /tmp/icemaker_global_tempdir.8RVjYmQMzzwG/rustc_testrunner_tmpdir_reporting.F427u8SIf55Q/mvce.rs:85:8
   |
85 |       _: union {
   |  ________^
86 | |         a: u8, 
87 | |     }  union ,
   | |_____^
   |
   = note: see issue #49804 <https://github.com/rust-lang/rust/issues/49804> for more information
   = help: add `#![feature(unnamed_fields)]` to the crate attributes to enable
   = note: this compiler was built on 2024-02-27; consider upgrading it if it is out of date

error[E0658]: unnamed fields are not yet fully implemented
  --> /tmp/icemaker_global_tempdir.8RVjYmQMzzwG/rustc_testrunner_tmpdir_reporting.F427u8SIf55Q/mvce.rs:94:5
   |
94 |     _: struct {
   |     ^
   |
   = note: see issue #49804 <https://github.com/rust-lang/rust/issues/49804> for more information
   = help: add `#![feature(unnamed_fields)]` to the crate attributes to enable
   = note: this compiler was built on 2024-02-27; consider upgrading it if it is out of date

error[E0658]: unnamed fields are not yet fully implemented
   --> /tmp/icemaker_global_tempdir.8RVjYmQMzzwG/rustc_testrunner_tmpdir_reporting.F427u8SIf55Q/mvce.rs:94:8
    |
94  |       _: struct {
    |  ________^
95  | |         
96  | |         ,
97  | |
...   |
101 | |           union  ,
102 | |     },
    | |_____^
    |
    = note: see issue #49804 <https://github.com/rust-lang/rust/issues/49804> for more information
    = help: add `#![feature(unnamed_fields)]` to the crate attributes to enable
    = note: this compiler was built on 2024-02-27; consider upgrading it if it is out of date

error[E0658]: unnamed fields are not yet fully implemented
   --> /tmp/icemaker_global_tempdir.8RVjYmQMzzwG/rustc_testrunner_tmpdir_reporting.F427u8SIf55Q/mvce.rs:112:5
    |
112 |     _: struct {
    |     ^
    |
    = note: see issue #49804 <https://github.com/rust-lang/rust/issues/49804> for more information
    = help: add `#![feature(unnamed_fields)]` to the crate attributes to enable
    = note: this compiler was built on 2024-02-27; consider upgrading it if it is out of date

error[E0658]: unnamed fields are not yet fully implemented
   --> /tmp/icemaker_global_tempdir.8RVjYmQMzzwG/rustc_testrunner_tmpdir_reporting.F427u8SIf55Q/mvce.rs:112:8
    |
112 |       _: struct {
    |  ________^
113 | |         
114 | |         ,
115 | |
...   |
119 | |           union  ,
120 | |     },
    | |_____^
    |
    = note: see issue #49804 <https://github.com/rust-lang/rust/issues/49804> for more information
    = help: add `#![feature(unnamed_fields)]` to the crate attributes to enable
    = note: this compiler was built on 2024-02-27; consider upgrading it if it is out of date

error[E0601]: `main` function not found in crate `mvce`
   --> /tmp/icemaker_global_tempdir.8RVjYmQMzzwG/rustc_testrunner_tmpdir_reporting.F427u8SIf55Q/mvce.rs:124:2
    |
124 | }
    |  ^ consider adding a `main` function to `/tmp/icemaker_global_tempdir.8RVjYmQMzzwG/rustc_testrunner_tmpdir_reporting.F427u8SIf55Q/mvce.rs`

error: internal compiler error: compiler/rustc_hir_analysis/src/collect.rs:906:32: Unexpected TyKind in FieldUniquenessCheckContext::check_field_in_nested_adt(): u8
 --> /tmp/icemaker_global_tempdir.8RVjYmQMzzwG/rustc_testrunner_tmpdir_reporting.F427u8SIf55Q/mvce.rs:7:5
  |
7 |     _: u8,
  |     ^^^^^

thread 'rustc' panicked at /rustc/ef324565d071c6d7e2477a195648549e33d6a465/compiler/rustc_middle/src/util/bug.rs:34:50:
Box<dyn Any>
stack backtrace:
   0:     0x7fd84e78cc46 - std::backtrace_rs::backtrace::libunwind::trace::hcd31ff68bb8eb3c8
                               at /rustc/ef324565d071c6d7e2477a195648549e33d6a465/library/std/src/../../backtrace/src/backtrace/libunwind.rs:104:5
   1:     0x7fd84e78cc46 - std::backtrace_rs::backtrace::trace_unsynchronized::h14d76bd5509bf096
                               at /rustc/ef324565d071c6d7e2477a195648549e33d6a465/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7fd84e78cc46 - std::sys_common::backtrace::_print_fmt::hccb1d92c773f2e33
                               at /rustc/ef324565d071c6d7e2477a195648549e33d6a465/library/std/src/sys_common/backtrace.rs:68:5
   3:     0x7fd84e78cc46 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::haec236aae0c71094
                               at /rustc/ef324565d071c6d7e2477a195648549e33d6a465/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x7fd84e7ddbcc - core::fmt::rt::Argument::fmt::hfe5c81d163ead061
                               at /rustc/ef324565d071c6d7e2477a195648549e33d6a465/library/core/src/fmt/rt.rs:142:9
   5:     0x7fd84e7ddbcc - core::fmt::write::hae70f68f90cda8d6
                               at /rustc/ef324565d071c6d7e2477a195648549e33d6a465/library/core/src/fmt/mod.rs:1120:17
   6:     0x7fd84e7814cf - std::io::Write::write_fmt::h2920683ffc23d04e
                               at /rustc/ef324565d071c6d7e2477a195648549e33d6a465/library/std/src/io/mod.rs:1846:15
   7:     0x7fd84e78c9f4 - std::sys_common::backtrace::_print::h5625fa16158ef797
                               at /rustc/ef324565d071c6d7e2477a195648549e33d6a465/library/std/src/sys_common/backtrace.rs:47:5
   8:     0x7fd84e78c9f4 - std::sys_common::backtrace::print::h736502c57d395fe5
                               at /rustc/ef324565d071c6d7e2477a195648549e33d6a465/library/std/src/sys_common/backtrace.rs:34:9
   9:     0x7fd84e78f73b - std::panicking::default_hook::{{closure}}::hd092ecfc821f695b
  10:     0x7fd84e78f489 - std::panicking::default_hook::h7f251f2c2a8aa52c
                               at /rustc/ef324565d071c6d7e2477a195648549e33d6a465/library/std/src/panicking.rs:292:9
  11:     0x7fd8516a5d3c - std[578157ee06130f18]::panicking::update_hook::<alloc[1f5b0d5bc2928dda]::boxed::Box<rustc_driver_impl[58539505cbc2faf7]::install_ice_hook::{closure#0}>>::{closure#0}
  12:     0x7fd84e78fea0 - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::hc774e046b4082d87
                               at /rustc/ef324565d071c6d7e2477a195648549e33d6a465/library/alloc/src/boxed.rs:2030:9
  13:     0x7fd84e78fea0 - std::panicking::rust_panic_with_hook::h50c9145ee7057605
                               at /rustc/ef324565d071c6d7e2477a195648549e33d6a465/library/std/src/panicking.rs:783:13
  14:     0x7fd8516d1d74 - std[578157ee06130f18]::panicking::begin_panic::<rustc_errors[2100e50554992a1d]::ExplicitBug>::{closure#0}
  15:     0x7fd8516ce9c6 - std[578157ee06130f18]::sys_common::backtrace::__rust_end_short_backtrace::<std[578157ee06130f18]::panicking::begin_panic<rustc_errors[2100e50554992a1d]::ExplicitBug>::{closure#0}, !>
  16:     0x7fd8516ca186 - std[578157ee06130f18]::panicking::begin_panic::<rustc_errors[2100e50554992a1d]::ExplicitBug>
  17:     0x7fd8516db8d1 - <rustc_errors[2100e50554992a1d]::diagnostic::BugAbort as rustc_errors[2100e50554992a1d]::diagnostic::EmissionGuarantee>::emit_producing_guarantee
  18:     0x7fd851780ac0 - rustc_middle[2ebf57413533262e]::util::bug::opt_span_bug_fmt::<rustc_span[20f1163f305bb5ee]::span_encoding::Span>::{closure#0}
  19:     0x7fd8517816ba - rustc_middle[2ebf57413533262e]::ty::context::tls::with_opt::<rustc_middle[2ebf57413533262e]::util::bug::opt_span_bug_fmt<rustc_span[20f1163f305bb5ee]::span_encoding::Span>::{closure#0}, !>::{closure#0}
  20:     0x7fd85176ab78 - rustc_middle[2ebf57413533262e]::ty::context::tls::with_context_opt::<rustc_middle[2ebf57413533262e]::ty::context::tls::with_opt<rustc_middle[2ebf57413533262e]::util::bug::opt_span_bug_fmt<rustc_span[20f1163f305bb5ee]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
  21:     0x7fd851766f24 - rustc_middle[2ebf57413533262e]::util::bug::span_bug_fmt::<rustc_span[20f1163f305bb5ee]::span_encoding::Span>
  22:     0x7fd8517d497b - <rustc_hir_analysis[b9c969b446149ad8]::collect::FieldUniquenessCheckContext>::check_field_in_nested_adt
  23:     0x7fd852f82f05 - rustc_hir_analysis[b9c969b446149ad8]::collect::convert_variant
  24:     0x7fd852f8275e - rustc_hir_analysis[b9c969b446149ad8]::collect::adt_def
  25:     0x7fd852a8b4d5 - rustc_query_impl[ba88ac09c9d7b12d]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[ba88ac09c9d7b12d]::query_impl::adt_def::dynamic_query::{closure#2}::{closure#0}, rustc_middle[2ebf57413533262e]::query::erase::Erased<[u8; 8usize]>>
  26:     0x7fd852a8bba0 - rustc_query_system[cf6fea66217b4faa]::query::plumbing::try_execute_query::<rustc_query_impl[ba88ac09c9d7b12d]::DynamicConfig<rustc_query_system[cf6fea66217b4faa]::query::caches::DefIdCache<rustc_middle[2ebf57413533262e]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[ba88ac09c9d7b12d]::plumbing::QueryCtxt, false>
  27:     0x7fd852a8aea2 - rustc_query_impl[ba88ac09c9d7b12d]::query_impl::adt_def::get_query_non_incr::__rust_end_short_backtrace
  28:     0x7fd852c3dc52 - rustc_middle[2ebf57413533262e]::query::plumbing::query_get_at::<rustc_query_system[cf6fea66217b4faa]::query::caches::DefIdCache<rustc_middle[2ebf57413533262e]::query::erase::Erased<[u8; 8usize]>>>
  29:     0x7fd853441853 - rustc_hir_analysis[b9c969b446149ad8]::outlives::inferred_outlives_crate
  30:     0x7fd8534406f0 - rustc_query_impl[ba88ac09c9d7b12d]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[ba88ac09c9d7b12d]::query_impl::inferred_outlives_crate::dynamic_query::{closure#2}::{closure#0}, rustc_middle[2ebf57413533262e]::query::erase::Erased<[u8; 8usize]>>
  31:     0x7fd8537bbe0e - rustc_query_system[cf6fea66217b4faa]::query::plumbing::try_execute_query::<rustc_query_impl[ba88ac09c9d7b12d]::DynamicConfig<rustc_query_system[cf6fea66217b4faa]::query::caches::SingleCache<rustc_middle[2ebf57413533262e]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[ba88ac09c9d7b12d]::plumbing::QueryCtxt, false>
  32:     0x7fd8537bc8a0 - rustc_query_impl[ba88ac09c9d7b12d]::query_impl::inferred_outlives_crate::get_query_non_incr::__rust_end_short_backtrace
  33:     0x7fd852d4fae3 - rustc_query_impl[ba88ac09c9d7b12d]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[ba88ac09c9d7b12d]::query_impl::inferred_outlives_of::dynamic_query::{closure#2}::{closure#0}, rustc_middle[2ebf57413533262e]::query::erase::Erased<[u8; 16usize]>>
  34:     0x7fd852d4e641 - rustc_query_system[cf6fea66217b4faa]::query::plumbing::try_execute_query::<rustc_query_impl[ba88ac09c9d7b12d]::DynamicConfig<rustc_query_system[cf6fea66217b4faa]::query::caches::DefIdCache<rustc_middle[2ebf57413533262e]::query::erase::Erased<[u8; 16usize]>>, false, false, false>, rustc_query_impl[ba88ac09c9d7b12d]::plumbing::QueryCtxt, false>
  35:     0x7fd852d4e35e - rustc_query_impl[ba88ac09c9d7b12d]::query_impl::inferred_outlives_of::get_query_non_incr::__rust_end_short_backtrace
  36:     0x7fd852afd455 - rustc_hir_analysis[b9c969b446149ad8]::collect::predicates_defined_on
  37:     0x7fd852afd2a1 - rustc_query_impl[ba88ac09c9d7b12d]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[ba88ac09c9d7b12d]::query_impl::predicates_defined_on::dynamic_query::{closure#2}::{closure#0}, rustc_middle[2ebf57413533262e]::query::erase::Erased<[u8; 24usize]>>
  38:     0x7fd852afd289 - <rustc_query_impl[ba88ac09c9d7b12d]::query_impl::predicates_defined_on::dynamic_query::{closure#2} as core[6cbd71b2db6ebc95]::ops::function::FnOnce<(rustc_middle[2ebf57413533262e]::ty::context::TyCtxt, rustc_span[20f1163f305bb5ee]::def_id::DefId)>>::call_once
  39:     0x7fd852afc566 - rustc_query_system[cf6fea66217b4faa]::query::plumbing::try_execute_query::<rustc_query_impl[ba88ac09c9d7b12d]::DynamicConfig<rustc_query_system[cf6fea66217b4faa]::query::caches::DefIdCache<rustc_middle[2ebf57413533262e]::query::erase::Erased<[u8; 24usize]>>, false, false, false>, rustc_query_impl[ba88ac09c9d7b12d]::plumbing::QueryCtxt, false>
  40:     0x7fd852afc0a0 - rustc_query_impl[ba88ac09c9d7b12d]::query_impl::predicates_defined_on::get_query_non_incr::__rust_end_short_backtrace
  41:     0x7fd852afb08c - rustc_hir_analysis[b9c969b446149ad8]::collect::predicates_of::predicates_of
  42:     0x7fd852afaf93 - rustc_query_impl[ba88ac09c9d7b12d]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[ba88ac09c9d7b12d]::query_impl::predicates_of::dynamic_query::{closure#2}::{closure#0}, rustc_middle[2ebf57413533262e]::query::erase::Erased<[u8; 24usize]>>
  43:     0x7fd852afc581 - rustc_query_system[cf6fea66217b4faa]::query::plumbing::try_execute_query::<rustc_query_impl[ba88ac09c9d7b12d]::DynamicConfig<rustc_query_system[cf6fea66217b4faa]::query::caches::DefIdCache<rustc_middle[2ebf57413533262e]::query::erase::Erased<[u8; 24usize]>>, false, false, false>, rustc_query_impl[ba88ac09c9d7b12d]::plumbing::QueryCtxt, false>
  44:     0x7fd852afc17e - rustc_query_impl[ba88ac09c9d7b12d]::query_impl::predicates_of::get_query_non_incr::__rust_end_short_backtrace
  45:     0x7fd852d9542a - <rustc_hir_analysis[b9c969b446149ad8]::collect::CollectItemTypesVisitor as rustc_hir[2b58f08a8a598f50]::intravisit::Visitor>::visit_item
  46:     0x7fd852d946ea - rustc_hir_analysis[b9c969b446149ad8]::collect::collect_mod_item_types
  47:     0x7fd852d94677 - rustc_query_impl[ba88ac09c9d7b12d]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[ba88ac09c9d7b12d]::query_impl::collect_mod_item_types::dynamic_query::{closure#2}::{closure#0}, rustc_middle[2ebf57413533262e]::query::erase::Erased<[u8; 0usize]>>
  48:     0x7fd85356edad - rustc_query_system[cf6fea66217b4faa]::query::plumbing::try_execute_query::<rustc_query_impl[ba88ac09c9d7b12d]::DynamicConfig<rustc_query_system[cf6fea66217b4faa]::query::caches::DefaultCache<rustc_span[20f1163f305bb5ee]::def_id::LocalModDefId, rustc_middle[2ebf57413533262e]::query::erase::Erased<[u8; 0usize]>>, false, false, false>, rustc_query_impl[ba88ac09c9d7b12d]::plumbing::QueryCtxt, false>
  49:     0x7fd85356e8d7 - rustc_query_impl[ba88ac09c9d7b12d]::query_impl::collect_mod_item_types::get_query_non_incr::__rust_end_short_backtrace
  50:     0x7fd8532c4b28 - rustc_hir_analysis[b9c969b446149ad8]::check_crate
  51:     0x7fd853565bef - rustc_interface[549d5cba17650390]::passes::analysis
  52:     0x7fd853565859 - rustc_query_impl[ba88ac09c9d7b12d]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[ba88ac09c9d7b12d]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[2ebf57413533262e]::query::erase::Erased<[u8; 1usize]>>
  53:     0x7fd853739325 - rustc_query_system[cf6fea66217b4faa]::query::plumbing::try_execute_query::<rustc_query_impl[ba88ac09c9d7b12d]::DynamicConfig<rustc_query_system[cf6fea66217b4faa]::query::caches::SingleCache<rustc_middle[2ebf57413533262e]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[ba88ac09c9d7b12d]::plumbing::QueryCtxt, false>
  54:     0x7fd853739089 - rustc_query_impl[ba88ac09c9d7b12d]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  55:     0x7fd853740c16 - rustc_interface[549d5cba17650390]::interface::run_compiler::<core[6cbd71b2db6ebc95]::result::Result<(), rustc_span[20f1163f305bb5ee]::ErrorGuaranteed>, rustc_driver_impl[58539505cbc2faf7]::run_compiler::{closure#0}>::{closure#0}
  56:     0x7fd8539e7dc5 - std[578157ee06130f18]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[549d5cba17650390]::util::run_in_thread_with_globals<rustc_interface[549d5cba17650390]::util::run_in_thread_pool_with_globals<rustc_interface[549d5cba17650390]::interface::run_compiler<core[6cbd71b2db6ebc95]::result::Result<(), rustc_span[20f1163f305bb5ee]::ErrorGuaranteed>, rustc_driver_impl[58539505cbc2faf7]::run_compiler::{closure#0}>::{closure#0}, core[6cbd71b2db6ebc95]::result::Result<(), rustc_span[20f1163f305bb5ee]::ErrorGuaranteed>>::{closure#0}, core[6cbd71b2db6ebc95]::result::Result<(), rustc_span[20f1163f305bb5ee]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[6cbd71b2db6ebc95]::result::Result<(), rustc_span[20f1163f305bb5ee]::ErrorGuaranteed>>
  57:     0x7fd8539e7bf2 - <<std[578157ee06130f18]::thread::Builder>::spawn_unchecked_<rustc_interface[549d5cba17650390]::util::run_in_thread_with_globals<rustc_interface[549d5cba17650390]::util::run_in_thread_pool_with_globals<rustc_interface[549d5cba17650390]::interface::run_compiler<core[6cbd71b2db6ebc95]::result::Result<(), rustc_span[20f1163f305bb5ee]::ErrorGuaranteed>, rustc_driver_impl[58539505cbc2faf7]::run_compiler::{closure#0}>::{closure#0}, core[6cbd71b2db6ebc95]::result::Result<(), rustc_span[20f1163f305bb5ee]::ErrorGuaranteed>>::{closure#0}, core[6cbd71b2db6ebc95]::result::Result<(), rustc_span[20f1163f305bb5ee]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[6cbd71b2db6ebc95]::result::Result<(), rustc_span[20f1163f305bb5ee]::ErrorGuaranteed>>::{closure#1} as core[6cbd71b2db6ebc95]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  58:     0x7fd84e799875 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::hbfe673f8fb6b1f32
                               at /rustc/ef324565d071c6d7e2477a195648549e33d6a465/library/alloc/src/boxed.rs:2016:9
  59:     0x7fd84e799875 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h91a1aab6b746134a
                               at /rustc/ef324565d071c6d7e2477a195648549e33d6a465/library/alloc/src/boxed.rs:2016:9
  60:     0x7fd84e799875 - std::sys::pal::unix::thread::Thread::new::thread_start::h8e91ee627a6e8489
                               at /rustc/ef324565d071c6d7e2477a195648549e33d6a465/library/std/src/sys/pal/unix/thread.rs:108:17
  61:     0x7fd84e58155a - <unknown>
  62:     0x7fd84e5fea3c - <unknown>
  63:                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 1.78.0-nightly (ef324565d 2024-02-27) running on x86_64-unknown-linux-gnu

query stack during panic:
#0 [adt_def] computing ADT definition for `D`
#1 [inferred_outlives_crate] computing the inferred outlives predicates for items in this crate
#2 [inferred_outlives_of] computing inferred outlives predicates of `Foo`
#3 [predicates_defined_on] computing predicates of `Foo`
#4 [predicates_of] computing predicates of `Foo`
#5 [collect_mod_item_types] collecting item types in top-level module
#6 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to 31 previous errors

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

[matthiaskrgr]

will try to clean up later.

[matthiaskrgr]

#[repr(C)]
struct Foo {
    _: u8,
}

#[repr(C)]
struct D {
    _: Foo,
}