panic: union with malformed array; `expected leaf, got Branch`

[matthiaskrgr]

pub union U {
    foo: [usize; ""],
}

fn main() {}

RUST_BACKTRACE=full rust-analyzer analysis-stats . --run-all-ide-things

Database loaded:     592.33ms, 229minstr, 48mb (metadata 301.88ms, 1010kinstr, 151kb; build 32.13ms, 180kinstr, 2144b)
  item trees: 1
  dependency lines of code: 1_467_433, item trees: 2_948
  dependency item stats: traits: 848, impl: 9_686, mods: 3_059, macro calls: 5_580, macro rules: 1_054
Item Tree Collection: 4.07s, 23ginstr, 427mb
  Total Statistics:
    crates: 1, mods: 1, decls: 3, bodies: 1, adts: 1, consts: 0, signatures: 3, variants: 1
  Workspace:
    traits: 0, macro_rules macros: 0, proc_macros: 0
    lines of code: 11, item trees: 1
    usages: traits: 0, impl: 0, mods: 0, macro calls: 0, macro rules: 0
  Dependencies:
    lines of code: 1_467_433, item trees: 2_948
    declarations: traits: 848, impl: 9_686, mods: 3_059, macro calls: 5_580, macro rules: 1_054
Item Collection:     2.44s, 11ginstr, 179mb
Crate lang items:    463.66ms, 2474minstr, 31mb
Expression Store Lowering: 283.02µs, 244kinstr, 5kb
  exprs: 1, ??ty: 0 (0%), ?ty: 0 (0%), !ty: 0
  pats: 0, ??ty: 0 (100%), ?ty: 0 (100%), !ty: 0
  panics: 0
Inference:           2.04ms, 703kinstr, 2486kb
MIR lowering:        51.01µs, 58kinstr, 16b
Mir failed bodies: 0 (0%)

thread 'main' (1808773) panicked at /rust/deps/ra-ap-rustc_type_ir-0.165.0/src/const_kind.rs:172:40:
expected leaf, got Branch([])
stack backtrace:
   0:     0x7f15806a6246 - <<std[74eb2aff46e51e81]::sys::backtrace::BacktraceLock>::print::DisplayBacktrace as core[7aff35c028b048a4]::fmt::Display>::fmt
   1:     0x7f1580e0ad52 - core[7aff35c028b048a4]::fmt::write
   2:     0x7f15806bb38c - <std[74eb2aff46e51e81]::sys::stdio::unix::Stderr as core[7aff35c028b048a4]::io::write::Write>::write_fmt
   3:     0x7f1580677e7a - std[74eb2aff46e51e81]::panicking::default_hook::{closure#0}
   4:     0x7f15806988e3 - std[74eb2aff46e51e81]::panicking::default_hook
   5:     0x7f1580698d4b - std[74eb2aff46e51e81]::panicking::panic_with_hook
   6:     0x7f1580677f32 - std[74eb2aff46e51e81]::panicking::panic_handler::{closure#0}
   7:     0x7f158066f3e9 - std[74eb2aff46e51e81]::sys::backtrace::__rust_end_short_backtrace::<std[74eb2aff46e51e81]::panicking::panic_handler::{closure#0}, !>
   8:     0x7f158067988d - __rustc[49844a0cf2bb6b0d]::rust_begin_unwind
   9:     0x7f157d433c7c - core[7aff35c028b048a4]::panicking::panic_fmt
  10:     0x55c22abbe029 - hir_ty[f58a0abe133f1c00]::consteval::try_const_usize
  11:     0x55c22ac3f0ae - <hir_ty[f58a0abe133f1c00]::layout::_::layout_of_ty_query_Configuration_ as salsa[8774cceebe7971b6]::function::Configuration>::execute
  12:     0x55c22aa4db39 - <salsa[8774cceebe7971b6]::function::IngredientImpl<hir_ty[f58a0abe133f1c00]::layout::_::layout_of_ty_query_Configuration_>>::execute
  13:     0x55c22abae1fc - hir_ty[f58a0abe133f1c00]::layout::layout_of_ty_query
  14:     0x55c22ac17139 - <core[7aff35c028b048a4]::iter::adapters::GenericShunt<core[7aff35c028b048a4]::iter::adapters::map::Map<core[7aff35c028b048a4]::iter::adapters::map::Map<core[7aff35c028b048a4]::iter::adapters::enumerate::Enumerate<core[7aff35c028b048a4]::slice::iter::Iter<hir_def[77d4259de2ed9023]::signatures::FieldData>>, <la_arena[f716c310310ca8c]::Arena<hir_def[77d4259de2ed9023]::signatures::FieldData>>::iter::{closure#0}>, <hir_ty[f58a0abe133f1c00]::layout::adt::_::layout_of_adt_query_Configuration_ as salsa[8774cceebe7971b6]::function::Configuration>::execute::inner_::{closure#0}::{closure#0}>, core[7aff35c028b048a4]::result::Result<core[7aff35c028b048a4]::convert::Infallible, hir_ty[f58a0abe133f1c00]::layout::LayoutError>> as core[7aff35c028b048a4]::iter::traits::iterator::Iterator>::next
  15:     0x55c22aa1d57a - <hir_ty[f58a0abe133f1c00]::layout::adt::_::layout_of_adt_query_Configuration_ as salsa[8774cceebe7971b6]::function::Configuration>::execute::inner_::{closure#0}
  16:     0x55c22ac47f88 - <hir_ty[f58a0abe133f1c00]::layout::adt::_::layout_of_adt_query_Configuration_ as salsa[8774cceebe7971b6]::function::Configuration>::execute
  17:     0x55c22aa57196 - <salsa[8774cceebe7971b6]::function::IngredientImpl<hir_ty[f58a0abe133f1c00]::layout::adt::_::layout_of_adt_query_Configuration_>>::execute
  18:     0x55c22abd4305 - hir_ty[f58a0abe133f1c00]::layout::adt::layout_of_adt_query
  19:     0x55c22b8196b7 - <rust_analyzer[f1820004a41e425c]::cli::flags::AnalysisStats>::run::{closure#3}
  20:     0x55c22b875762 - <rust_analyzer[f1820004a41e425c]::cli::flags::AnalysisStats>::run
  21:     0x55c22bab4fd6 - rust_analyzer[c4fd19d1c3329aa5]::main
  22:     0x55c22bab1373 - std[74eb2aff46e51e81]::sys::backtrace::__rust_begin_short_backtrace::<fn() -> core[7aff35c028b048a4]::result::Result<std[74eb2aff46e51e81]::process::ExitCode, anyhow[f3ff20ce718c24c8]::Error>, core[7aff35c028b048a4]::result::Result<std[74eb2aff46e51e81]::process::ExitCode, anyhow[f3ff20ce718c24c8]::Error>>
  23:     0x55c22bab30d2 - std[74eb2aff46e51e81]::rt::lang_start::<core[7aff35c028b048a4]::result::Result<std[74eb2aff46e51e81]::process::ExitCode, anyhow[f3ff20ce718c24c8]::Error>>::{closure#0}
  24:     0x7f1581f03553 - std[74eb2aff46e51e81]::rt::lang_start_internal
  25:     0x55c22bacbb68 - main
  26:     0x7f157b427741 - <unknown>
  27:     0x7f157b427879 - __libc_start_main
  28:     0x55c22a3afed9 - <unknown>
  29:                0x0 - <unknown>