ICE: `offset of not-statically-aligned field .. cannot be computed statically`

[matthiaskrgr]

auto-reduced (treereduce-rust):

//@compile-flags: --edition=2024
#![feature(generic_const_exprs)]

use core::fmt::Debug;

struct Inline<T>
where
    [(); std::mem::offset_of!((T,), 0)]:,
{
    let foo: (),
    
}

fn main() {
    let dst = Inline::<dyn Debug>::new(0); // BANG!
}

original:

#![feature(generic_const_exprs)]

use core::fmt::Debug;

struct Inline<T>
where
    [(); std::mem::offset_of!((T,), 0)]:,
{
    let foo: (),
    //~^  ERROR expected identifier, found keyword `let`
}

fn main() {
    let dst = Inline::<dyn Debug>::new(0); // BANG!
}

Version information

rustc 1.86.0-nightly (2f348cb7c 2025-01-27)
binary: rustc
commit-hash: 2f348cb7ce4063fa4eb40038e6ada3c5214717bd
commit-date: 2025-01-27
host: x86_64-unknown-linux-gnu
release: 1.86.0-nightly
LLVM version: 19.1.7

Command:
/home/matthias/.rustup/toolchains/master/bin/rustc --edition=2024

Program output

error: expected identifier, found keyword `let`
 --> /tmp/icemaker_global_tempdir.ss1hYVHGdMgO/rustc_testrunner_tmpdir_reporting.pEd6k8w10N6f/mvce.rs:9:5
  |
9 |     let foo: (),
  |     ^^^-
  |     |
  |     expected identifier, found keyword
  |     help: remove this `let` keyword
  |
  = note: the `let` keyword is not allowed in `struct` fields
  = note: see <https://doc.rust-lang.org/book/ch05-01-defining-structs.html> for more information

warning: the feature `generic_const_exprs` is incomplete and may not be safe to use and/or cause compiler crashes
 --> /tmp/icemaker_global_tempdir.ss1hYVHGdMgO/rustc_testrunner_tmpdir_reporting.pEd6k8w10N6f/mvce.rs:1:12
  |
1 | #![feature(generic_const_exprs)]
  |            ^^^^^^^^^^^^^^^^^^^
  |
  = note: see issue #76560 <https://github.com/rust-lang/rust/issues/76560> for more information
  = note: `#[warn(incomplete_features)]` on by default

error[E0392]: type parameter `T` is never used
 --> /tmp/icemaker_global_tempdir.ss1hYVHGdMgO/rustc_testrunner_tmpdir_reporting.pEd6k8w10N6f/mvce.rs:5:15
  |
5 | struct Inline<T>
  |               ^ unused type parameter
  |
  = help: consider removing `T`, referring to it in a field, or using a marker such as `PhantomData`
  = help: if you intended `T` to be a const parameter, use `const T: /* Type */` instead

error[E0599]: no function or associated item named `new` found for struct `Inline` in the current scope
  --> /tmp/icemaker_global_tempdir.ss1hYVHGdMgO/rustc_testrunner_tmpdir_reporting.pEd6k8w10N6f/mvce.rs:14:36
   |
5  | struct Inline<T>
   | ---------------- function or associated item `new` not found for this struct
...
14 |     let dst = Inline::<dyn Debug>::new(0); // BANG!
   |                                    ^^^ function or associated item not found in `Inline<dyn Debug>`

error: internal compiler error: /rustc/2f348cb7ce4063fa4eb40038e6ada3c5214717bd/compiler/rustc_middle/src/ty/layout.rs:1397:21: offset of not-statically-aligned field (type dyn [Binder { value: Trait(std::fmt::Debug), bound_vars: [] }] + '{erased}) cannot be computed statically


thread 'rustc' panicked at /rustc/2f348cb7ce4063fa4eb40038e6ada3c5214717bd/compiler/rustc_middle/src/ty/layout.rs:1397:21:
Box<dyn Any>
stack backtrace:
   0:     0x7e903a3aae40 - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::he98e11da2daa96a9
   1:     0x7e903ac14ee6 - core::fmt::write::had177877e89931fb
   2:     0x7e903bb50b51 - std::io::Write::write_fmt::hc355e6fef9c0a3ce
   3:     0x7e903a3aaca2 - std::sys::backtrace::BacktraceLock::print::h676c1f81be95e0b1
   4:     0x7e903a3ad122 - std::panicking::default_hook::{{closure}}::hd28d3669866dc126
   5:     0x7e903a3acfaa - std::panicking::default_hook::h039746809c2c5ae1
   6:     0x7e903955ff39 - std[644fad426ed526f7]::panicking::update_hook::<alloc[5097d557d6b96634]::boxed::Box<rustc_driver_impl[438371d8e84705cb]::install_ice_hook::{closure#1}>>::{closure#0}
   7:     0x7e903a3adc63 - std::panicking::rust_panic_with_hook::h88108df39d1d1441
   8:     0x7e903959b421 - std[644fad426ed526f7]::panicking::begin_panic::<rustc_errors[d6afe1f3c80315c7]::ExplicitBug>::{closure#0}
   9:     0x7e9039590326 - std[644fad426ed526f7]::sys::backtrace::__rust_end_short_backtrace::<std[644fad426ed526f7]::panicking::begin_panic<rustc_errors[d6afe1f3c80315c7]::ExplicitBug>::{closure#0}, !>
  10:     0x7e903958d05d - std[644fad426ed526f7]::panicking::begin_panic::<rustc_errors[d6afe1f3c80315c7]::ExplicitBug>
  11:     0x7e90395a5351 - <rustc_errors[d6afe1f3c80315c7]::diagnostic::BugAbort as rustc_errors[d6afe1f3c80315c7]::diagnostic::EmissionGuarantee>::emit_producing_guarantee
  12:     0x7e9039b867f3 - rustc_middle[dfbbc45bb841e134]::util::bug::opt_span_bug_fmt::<rustc_span[45d362c5296a3b7f]::span_encoding::Span>::{closure#0}
  13:     0x7e9039b6f7aa - rustc_middle[dfbbc45bb841e134]::ty::context::tls::with_opt::<rustc_middle[dfbbc45bb841e134]::util::bug::opt_span_bug_fmt<rustc_span[45d362c5296a3b7f]::span_encoding::Span>::{closure#0}, !>::{closure#0}
  14:     0x7e9039b6f63b - rustc_middle[dfbbc45bb841e134]::ty::context::tls::with_context_opt::<rustc_middle[dfbbc45bb841e134]::ty::context::tls::with_opt<rustc_middle[dfbbc45bb841e134]::util::bug::opt_span_bug_fmt<rustc_span[45d362c5296a3b7f]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
  15:     0x7e9037de19a0 - rustc_middle[dfbbc45bb841e134]::util::bug::bug_fmt
  16:     0x7e903b7a4bb5 - <rustc_const_eval[4c73f18587537670]::interpret::eval_context::InterpCx<rustc_const_eval[4c73f18587537670]::const_eval::machine::CompileTimeMachine>>::eval_rvalue_into_place
  17:     0x7e90385dce39 - rustc_const_eval[4c73f18587537670]::const_eval::eval_queries::eval_to_allocation_raw_provider
  18:     0x7e903b412e9c - rustc_query_impl[9923fb681be542d6]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[9923fb681be542d6]::query_impl::eval_to_allocation_raw::dynamic_query::{closure#2}::{closure#0}, rustc_middle[dfbbc45bb841e134]::query::erase::Erased<[u8; 24usize]>>
  19:     0x7e903b41283a - rustc_query_system[ea81b1814f2bc579]::query::plumbing::try_execute_query::<rustc_query_impl[9923fb681be542d6]::DynamicConfig<rustc_query_system[ea81b1814f2bc579]::query::caches::DefaultCache<rustc_middle[dfbbc45bb841e134]::ty::PseudoCanonicalInput<rustc_middle[dfbbc45bb841e134]::mir::interpret::GlobalId>, rustc_middle[dfbbc45bb841e134]::query::erase::Erased<[u8; 24usize]>>, false, false, false>, rustc_query_impl[9923fb681be542d6]::plumbing::QueryCtxt, false>
  20:     0x7e903b4124bb - rustc_query_impl[9923fb681be542d6]::query_impl::eval_to_allocation_raw::get_query_non_incr::__rust_end_short_backtrace
  21:     0x7e903b419d65 - rustc_const_eval[4c73f18587537670]::const_eval::valtrees::eval_to_valtree
  22:     0x7e903b419b1c - <rustc_const_eval[4c73f18587537670]::provide::{closure#0} as core[d2a938784d8f7dcb]::ops::function::FnOnce<(rustc_middle[dfbbc45bb841e134]::ty::context::TyCtxt, rustc_middle[dfbbc45bb841e134]::ty::PseudoCanonicalInput<rustc_middle[dfbbc45bb841e134]::mir::interpret::GlobalId>)>>::call_once
  23:     0x7e903b419ac6 - rustc_query_impl[9923fb681be542d6]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[9923fb681be542d6]::query_impl::eval_to_valtree::dynamic_query::{closure#2}::{closure#0}, rustc_middle[dfbbc45bb841e134]::query::erase::Erased<[u8; 24usize]>>
  24:     0x7e903b419a7f - <rustc_query_impl[9923fb681be542d6]::query_impl::eval_to_valtree::dynamic_query::{closure#2} as core[d2a938784d8f7dcb]::ops::function::FnOnce<(rustc_middle[dfbbc45bb841e134]::ty::context::TyCtxt, rustc_middle[dfbbc45bb841e134]::ty::PseudoCanonicalInput<rustc_middle[dfbbc45bb841e134]::mir::interpret::GlobalId>)>>::call_once
  25:     0x7e903b412913 - rustc_query_system[ea81b1814f2bc579]::query::plumbing::try_execute_query::<rustc_query_impl[9923fb681be542d6]::DynamicConfig<rustc_query_system[ea81b1814f2bc579]::query::caches::DefaultCache<rustc_middle[dfbbc45bb841e134]::ty::PseudoCanonicalInput<rustc_middle[dfbbc45bb841e134]::mir::interpret::GlobalId>, rustc_middle[dfbbc45bb841e134]::query::erase::Erased<[u8; 24usize]>>, false, false, false>, rustc_query_impl[9923fb681be542d6]::plumbing::QueryCtxt, false>
  26:     0x7e903b41222d - rustc_query_impl[9923fb681be542d6]::query_impl::eval_to_valtree::get_query_non_incr::__rust_end_short_backtrace
  27:     0x7e903b7d390c - rustc_middle[dfbbc45bb841e134]::query::plumbing::query_get_at::<rustc_query_system[ea81b1814f2bc579]::query::caches::DefaultCache<rustc_middle[dfbbc45bb841e134]::ty::PseudoCanonicalInput<rustc_middle[dfbbc45bb841e134]::mir::interpret::GlobalId>, rustc_middle[dfbbc45bb841e134]::query::erase::Erased<[u8; 24usize]>>>
  28:     0x7e903b7d2f22 - <rustc_middle[dfbbc45bb841e134]::ty::context::TyCtxt>::const_eval_global_id_for_typeck
  29:     0x7e903b7d2db9 - <rustc_middle[dfbbc45bb841e134]::ty::context::TyCtxt>::const_eval_resolve_for_typeck
  30:     0x7e903b7d2af7 - rustc_trait_selection[a0c4a4c304b8efe3]::traits::try_evaluate_const
  31:     0x7e903c894ef8 - rustc_trait_selection[a0c4a4c304b8efe3]::traits::const_evaluatable::is_const_evaluatable.cold
  32:     0x7e903b4ee30f - <rustc_trait_selection[a0c4a4c304b8efe3]::traits::fulfill::FulfillProcessor as rustc_data_structures[702a32bac37c74a0]::obligation_forest::ObligationProcessor>::process_obligation
  33:     0x7e903ac10642 - <rustc_data_structures[702a32bac37c74a0]::obligation_forest::ObligationForest<rustc_trait_selection[a0c4a4c304b8efe3]::traits::fulfill::PendingPredicateObligation>>::process_obligations::<rustc_trait_selection[a0c4a4c304b8efe3]::traits::fulfill::FulfillProcessor>
  34:     0x7e903ad69f6a - <rustc_hir_typeck[711cb0c541d6273d]::fn_ctxt::FnCtxt>::try_structurally_resolve_type
  35:     0x7e903b9899fd - <rustc_hir_typeck[711cb0c541d6273d]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  36:     0x7e903ad7b371 - <rustc_hir_typeck[711cb0c541d6273d]::fn_ctxt::FnCtxt>::confirm_builtin_call
  37:     0x7e903b98b526 - <rustc_hir_typeck[711cb0c541d6273d]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  38:     0x7e903b9885e7 - <rustc_hir_typeck[711cb0c541d6273d]::fn_ctxt::FnCtxt>::check_decl
  39:     0x7e903b9856cd - <rustc_hir_typeck[711cb0c541d6273d]::fn_ctxt::FnCtxt>::check_expr_block
  40:     0x7e903b98c03e - <rustc_hir_typeck[711cb0c541d6273d]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  41:     0x7e903b240d00 - rustc_hir_typeck[711cb0c541d6273d]::check::check_fn
  42:     0x7e903b249b7d - rustc_hir_typeck[711cb0c541d6273d]::typeck_with_inspect::{closure#0}
  43:     0x7e903b247b8c - rustc_query_impl[9923fb681be542d6]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[9923fb681be542d6]::query_impl::typeck::dynamic_query::{closure#2}::{closure#0}, rustc_middle[dfbbc45bb841e134]::query::erase::Erased<[u8; 8usize]>>
  44:     0x7e903af996ce - rustc_query_system[ea81b1814f2bc579]::query::plumbing::try_execute_query::<rustc_query_impl[9923fb681be542d6]::DynamicConfig<rustc_data_structures[702a32bac37c74a0]::vec_cache::VecCache<rustc_span[45d362c5296a3b7f]::def_id::LocalDefId, rustc_middle[dfbbc45bb841e134]::query::erase::Erased<[u8; 8usize]>, rustc_query_system[ea81b1814f2bc579]::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl[9923fb681be542d6]::plumbing::QueryCtxt, false>
  45:     0x7e903af97bd1 - rustc_query_impl[9923fb681be542d6]::query_impl::typeck::get_query_non_incr::__rust_end_short_backtrace
  46:     0x7e903af9788b - <rustc_middle[dfbbc45bb841e134]::hir::map::Map>::par_body_owners::<rustc_hir_analysis[679b9e311f2f4bbc]::check_crate::{closure#4}>::{closure#0}
  47:     0x7e903af9593f - rustc_hir_analysis[679b9e311f2f4bbc]::check_crate
  48:     0x7e903af91f62 - rustc_interface[68fc4f7f4eaa26cf]::passes::run_required_analyses
  49:     0x7e903bb4c25e - rustc_interface[68fc4f7f4eaa26cf]::passes::analysis
  50:     0x7e903bb4c22f - rustc_query_impl[9923fb681be542d6]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[9923fb681be542d6]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[dfbbc45bb841e134]::query::erase::Erased<[u8; 0usize]>>
  51:     0x7e903bb29855 - rustc_query_system[ea81b1814f2bc579]::query::plumbing::try_execute_query::<rustc_query_impl[9923fb681be542d6]::DynamicConfig<rustc_query_system[ea81b1814f2bc579]::query::caches::SingleCache<rustc_middle[dfbbc45bb841e134]::query::erase::Erased<[u8; 0usize]>>, false, false, false>, rustc_query_impl[9923fb681be542d6]::plumbing::QueryCtxt, false>
  52:     0x7e903bb2958e - rustc_query_impl[9923fb681be542d6]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  53:     0x7e903bb65169 - rustc_interface[68fc4f7f4eaa26cf]::passes::create_and_enter_global_ctxt::<core[d2a938784d8f7dcb]::option::Option<rustc_interface[68fc4f7f4eaa26cf]::queries::Linker>, rustc_driver_impl[438371d8e84705cb]::run_compiler::{closure#0}::{closure#2}>::{closure#2}::{closure#0}
  54:     0x7e903bba250a - rustc_interface[68fc4f7f4eaa26cf]::interface::run_compiler::<(), rustc_driver_impl[438371d8e84705cb]::run_compiler::{closure#0}>::{closure#1}
  55:     0x7e903ba8a875 - std[644fad426ed526f7]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[68fc4f7f4eaa26cf]::util::run_in_thread_with_globals<rustc_interface[68fc4f7f4eaa26cf]::util::run_in_thread_pool_with_globals<rustc_interface[68fc4f7f4eaa26cf]::interface::run_compiler<(), rustc_driver_impl[438371d8e84705cb]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
  56:     0x7e903ba8a559 - <<std[644fad426ed526f7]::thread::Builder>::spawn_unchecked_<rustc_interface[68fc4f7f4eaa26cf]::util::run_in_thread_with_globals<rustc_interface[68fc4f7f4eaa26cf]::util::run_in_thread_pool_with_globals<rustc_interface[68fc4f7f4eaa26cf]::interface::run_compiler<(), rustc_driver_impl[438371d8e84705cb]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core[d2a938784d8f7dcb]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  57:     0x7e903ba89ceb - std::sys::pal::unix::thread::Thread::new::thread_start::h6b29fca7c6a267b7
  58:     0x7e9035ca339d - <unknown>
  59:     0x7e9035d2849c - <unknown>
  60:                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: please make sure that you have updated to the latest nightly

note: rustc 1.86.0-nightly (2f348cb7c 2025-01-27) running on x86_64-unknown-linux-gnu

note: compiler flags: -Z dump-mir-dir=dir

query stack during panic:
#0 [eval_to_allocation_raw] const-evaluating + checking `Inline::{constant#0}`
#1 [eval_to_valtree] evaluating type-level constant
#2 [typeck] type-checking `main`
#3 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to 4 previous errors; 1 warning emitted

Some errors have detailed explanations: E0392, E0599.
For more information about an error, try `rustc --explain E0392`.

@rustbot label +F-generic_const_exprs

[matthiaskrgr]

smaller:

//@ compile-flags: --edition=2024
#![feature(generic_const_exprs)]
struct A<B>
where
    [(); std::mem::offset_of!((B,), 0)]:;

fn c<DynSized>() -> A<DynSized> {
    A::<dyn Sized>
}

pub fn main() {}

[theemathas]

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

trait Trait {}

struct A<T>(T)
where
    [(); std::mem::offset_of!((T,), 0)]:;

fn main() {
    let x: A<dyn Trait>;
}

Error output

error: internal compiler error: /rustc/2f348cb7ce4063fa4eb40038e6ada3c5214717bd/compiler/rustc_middle/src/ty/layout.rs:1397:21: offset of not-statically-aligned field (type dyn [Binder { value: Trait(Trait), bound_vars: [] }] + '{erased}) cannot be computed statically


thread 'rustc' panicked at /rustc/2f348cb7ce4063fa4eb40038e6ada3c5214717bd/compiler/rustc_middle/src/ty/layout.rs:1397:21:
Box<dyn Any>
stack backtrace:
   0:     0x705339faae40 - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::he98e11da2daa96a9
   1:     0x70533a814ee6 - core::fmt::write::had177877e89931fb
   2:     0x70533b750b51 - std::io::Write::write_fmt::hc355e6fef9c0a3ce
   3:     0x705339faaca2 - std::sys::backtrace::BacktraceLock::print::h676c1f81be95e0b1
   4:     0x705339fad122 - std::panicking::default_hook::{{closure}}::hd28d3669866dc126
   5:     0x705339facfaa - std::panicking::default_hook::h039746809c2c5ae1
   6:     0x70533915ff39 - std[644fad426ed526f7]::panicking::update_hook::<alloc[5097d557d6b96634]::boxed::Box<rustc_driver_impl[438371d8e84705cb]::install_ice_hook::{closure#1}>>::{closure#0}
   7:     0x705339fadc63 - std::panicking::rust_panic_with_hook::h88108df39d1d1441
   8:     0x70533919b421 - std[644fad426ed526f7]::panicking::begin_panic::<rustc_errors[d6afe1f3c80315c7]::ExplicitBug>::{closure#0}
   9:     0x705339190326 - std[644fad426ed526f7]::sys::backtrace::__rust_end_short_backtrace::<std[644fad426ed526f7]::panicking::begin_panic<rustc_errors[d6afe1f3c80315c7]::ExplicitBug>::{closure#0}, !>
  10:     0x70533918d05d - std[644fad426ed526f7]::panicking::begin_panic::<rustc_errors[d6afe1f3c80315c7]::ExplicitBug>
  11:     0x7053391a5351 - <rustc_errors[d6afe1f3c80315c7]::diagnostic::BugAbort as rustc_errors[d6afe1f3c80315c7]::diagnostic::EmissionGuarantee>::emit_producing_guarantee
  12:     0x7053397867f3 - rustc_middle[dfbbc45bb841e134]::util::bug::opt_span_bug_fmt::<rustc_span[45d362c5296a3b7f]::span_encoding::Span>::{closure#0}
  13:     0x70533976f7aa - rustc_middle[dfbbc45bb841e134]::ty::context::tls::with_opt::<rustc_middle[dfbbc45bb841e134]::util::bug::opt_span_bug_fmt<rustc_span[45d362c5296a3b7f]::span_encoding::Span>::{closure#0}, !>::{closure#0}
  14:     0x70533976f63b - rustc_middle[dfbbc45bb841e134]::ty::context::tls::with_context_opt::<rustc_middle[dfbbc45bb841e134]::ty::context::tls::with_opt<rustc_middle[dfbbc45bb841e134]::util::bug::opt_span_bug_fmt<rustc_span[45d362c5296a3b7f]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
  15:     0x7053379e19a0 - rustc_middle[dfbbc45bb841e134]::util::bug::bug_fmt
  16:     0x70533b3a4bb5 - <rustc_const_eval[4c73f18587537670]::interpret::eval_context::InterpCx<rustc_const_eval[4c73f18587537670]::const_eval::machine::CompileTimeMachine>>::eval_rvalue_into_place
  17:     0x7053381dce39 - rustc_const_eval[4c73f18587537670]::const_eval::eval_queries::eval_to_allocation_raw_provider
  18:     0x70533b012e9c - rustc_query_impl[9923fb681be542d6]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[9923fb681be542d6]::query_impl::eval_to_allocation_raw::dynamic_query::{closure#2}::{closure#0}, rustc_middle[dfbbc45bb841e134]::query::erase::Erased<[u8; 24usize]>>
  19:     0x70533b01283a - rustc_query_system[ea81b1814f2bc579]::query::plumbing::try_execute_query::<rustc_query_impl[9923fb681be542d6]::DynamicConfig<rustc_query_system[ea81b1814f2bc579]::query::caches::DefaultCache<rustc_middle[dfbbc45bb841e134]::ty::PseudoCanonicalInput<rustc_middle[dfbbc45bb841e134]::mir::interpret::GlobalId>, rustc_middle[dfbbc45bb841e134]::query::erase::Erased<[u8; 24usize]>>, false, false, false>, rustc_query_impl[9923fb681be542d6]::plumbing::QueryCtxt, false>
  20:     0x70533b0124bb - rustc_query_impl[9923fb681be542d6]::query_impl::eval_to_allocation_raw::get_query_non_incr::__rust_end_short_backtrace
  21:     0x70533b019d65 - rustc_const_eval[4c73f18587537670]::const_eval::valtrees::eval_to_valtree
  22:     0x70533b019b1c - <rustc_const_eval[4c73f18587537670]::provide::{closure#0} as core[d2a938784d8f7dcb]::ops::function::FnOnce<(rustc_middle[dfbbc45bb841e134]::ty::context::TyCtxt, rustc_middle[dfbbc45bb841e134]::ty::PseudoCanonicalInput<rustc_middle[dfbbc45bb841e134]::mir::interpret::GlobalId>)>>::call_once
  23:     0x70533b019ac6 - rustc_query_impl[9923fb681be542d6]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[9923fb681be542d6]::query_impl::eval_to_valtree::dynamic_query::{closure#2}::{closure#0}, rustc_middle[dfbbc45bb841e134]::query::erase::Erased<[u8; 24usize]>>
  24:     0x70533b019a7f - <rustc_query_impl[9923fb681be542d6]::query_impl::eval_to_valtree::dynamic_query::{closure#2} as core[d2a938784d8f7dcb]::ops::function::FnOnce<(rustc_middle[dfbbc45bb841e134]::ty::context::TyCtxt, rustc_middle[dfbbc45bb841e134]::ty::PseudoCanonicalInput<rustc_middle[dfbbc45bb841e134]::mir::interpret::GlobalId>)>>::call_once
  25:     0x70533b012913 - rustc_query_system[ea81b1814f2bc579]::query::plumbing::try_execute_query::<rustc_query_impl[9923fb681be542d6]::DynamicConfig<rustc_query_system[ea81b1814f2bc579]::query::caches::DefaultCache<rustc_middle[dfbbc45bb841e134]::ty::PseudoCanonicalInput<rustc_middle[dfbbc45bb841e134]::mir::interpret::GlobalId>, rustc_middle[dfbbc45bb841e134]::query::erase::Erased<[u8; 24usize]>>, false, false, false>, rustc_query_impl[9923fb681be542d6]::plumbing::QueryCtxt, false>
  26:     0x70533b01222d - rustc_query_impl[9923fb681be542d6]::query_impl::eval_to_valtree::get_query_non_incr::__rust_end_short_backtrace
  27:     0x70533b3d390c - rustc_middle[dfbbc45bb841e134]::query::plumbing::query_get_at::<rustc_query_system[ea81b1814f2bc579]::query::caches::DefaultCache<rustc_middle[dfbbc45bb841e134]::ty::PseudoCanonicalInput<rustc_middle[dfbbc45bb841e134]::mir::interpret::GlobalId>, rustc_middle[dfbbc45bb841e134]::query::erase::Erased<[u8; 24usize]>>>
  28:     0x70533b3d2f22 - <rustc_middle[dfbbc45bb841e134]::ty::context::TyCtxt>::const_eval_global_id_for_typeck
  29:     0x70533b3d2db9 - <rustc_middle[dfbbc45bb841e134]::ty::context::TyCtxt>::const_eval_resolve_for_typeck
  30:     0x70533b3d2af7 - rustc_trait_selection[a0c4a4c304b8efe3]::traits::try_evaluate_const
  31:     0x70533c494ef8 - rustc_trait_selection[a0c4a4c304b8efe3]::traits::const_evaluatable::is_const_evaluatable.cold
  32:     0x70533b0ee30f - <rustc_trait_selection[a0c4a4c304b8efe3]::traits::fulfill::FulfillProcessor as rustc_data_structures[702a32bac37c74a0]::obligation_forest::ObligationProcessor>::process_obligation
  33:     0x70533a810642 - <rustc_data_structures[702a32bac37c74a0]::obligation_forest::ObligationForest<rustc_trait_selection[a0c4a4c304b8efe3]::traits::fulfill::PendingPredicateObligation>>::process_obligations::<rustc_trait_selection[a0c4a4c304b8efe3]::traits::fulfill::FulfillProcessor>
  34:     0x70533ae49c43 - rustc_hir_typeck[711cb0c541d6273d]::typeck_with_inspect::{closure#0}
  35:     0x70533ae47b8c - rustc_query_impl[9923fb681be542d6]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[9923fb681be542d6]::query_impl::typeck::dynamic_query::{closure#2}::{closure#0}, rustc_middle[dfbbc45bb841e134]::query::erase::Erased<[u8; 8usize]>>
  36:     0x70533ab996ce - rustc_query_system[ea81b1814f2bc579]::query::plumbing::try_execute_query::<rustc_query_impl[9923fb681be542d6]::DynamicConfig<rustc_data_structures[702a32bac37c74a0]::vec_cache::VecCache<rustc_span[45d362c5296a3b7f]::def_id::LocalDefId, rustc_middle[dfbbc45bb841e134]::query::erase::Erased<[u8; 8usize]>, rustc_query_system[ea81b1814f2bc579]::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl[9923fb681be542d6]::plumbing::QueryCtxt, false>
  37:     0x70533ab97bd1 - rustc_query_impl[9923fb681be542d6]::query_impl::typeck::get_query_non_incr::__rust_end_short_backtrace
  38:     0x70533ab9788b - <rustc_middle[dfbbc45bb841e134]::hir::map::Map>::par_body_owners::<rustc_hir_analysis[679b9e311f2f4bbc]::check_crate::{closure#4}>::{closure#0}
  39:     0x70533ab9593f - rustc_hir_analysis[679b9e311f2f4bbc]::check_crate
  40:     0x70533ab91f62 - rustc_interface[68fc4f7f4eaa26cf]::passes::run_required_analyses
  41:     0x70533b74c25e - rustc_interface[68fc4f7f4eaa26cf]::passes::analysis
  42:     0x70533b74c22f - rustc_query_impl[9923fb681be542d6]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[9923fb681be542d6]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[dfbbc45bb841e134]::query::erase::Erased<[u8; 0usize]>>
  43:     0x70533b729855 - rustc_query_system[ea81b1814f2bc579]::query::plumbing::try_execute_query::<rustc_query_impl[9923fb681be542d6]::DynamicConfig<rustc_query_system[ea81b1814f2bc579]::query::caches::SingleCache<rustc_middle[dfbbc45bb841e134]::query::erase::Erased<[u8; 0usize]>>, false, false, false>, rustc_query_impl[9923fb681be542d6]::plumbing::QueryCtxt, false>
  44:     0x70533b72958e - rustc_query_impl[9923fb681be542d6]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  45:     0x70533b765169 - rustc_interface[68fc4f7f4eaa26cf]::passes::create_and_enter_global_ctxt::<core[d2a938784d8f7dcb]::option::Option<rustc_interface[68fc4f7f4eaa26cf]::queries::Linker>, rustc_driver_impl[438371d8e84705cb]::run_compiler::{closure#0}::{closure#2}>::{closure#2}::{closure#0}
  46:     0x70533b7a250a - rustc_interface[68fc4f7f4eaa26cf]::interface::run_compiler::<(), rustc_driver_impl[438371d8e84705cb]::run_compiler::{closure#0}>::{closure#1}
  47:     0x70533b68a875 - std[644fad426ed526f7]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[68fc4f7f4eaa26cf]::util::run_in_thread_with_globals<rustc_interface[68fc4f7f4eaa26cf]::util::run_in_thread_pool_with_globals<rustc_interface[68fc4f7f4eaa26cf]::interface::run_compiler<(), rustc_driver_impl[438371d8e84705cb]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
  48:     0x70533b68a559 - <<std[644fad426ed526f7]::thread::Builder>::spawn_unchecked_<rustc_interface[68fc4f7f4eaa26cf]::util::run_in_thread_with_globals<rustc_interface[68fc4f7f4eaa26cf]::util::run_in_thread_pool_with_globals<rustc_interface[68fc4f7f4eaa26cf]::interface::run_compiler<(), rustc_driver_impl[438371d8e84705cb]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core[d2a938784d8f7dcb]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  49:     0x70533b689ceb - std::sys::pal::unix::thread::Thread::new::thread_start::h6b29fca7c6a267b7
  50:     0x70533cfb2a94 - <unknown>
  51:     0x70533d03fa34 - clone
  52:                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: please make sure that you have updated to the latest nightly

note: please attach the file at `/playground/rustc-ice-2025-01-28T08_57_07-163.txt` to your bug report

note: compiler flags: --crate-type bin -C embed-bitcode=no -C codegen-units=1 -C debuginfo=2

note: some of the compiler flags provided by cargo are hidden

query stack during panic:
#0 [eval_to_allocation_raw] const-evaluating + checking `A::{constant#0}`
#1 [eval_to_valtree] evaluating type-level constant
... and 2 other queries... use `env RUST_BACKTRACE=1` to see the full query stack
error: could not compile `playground` (bin "playground")

[theemathas]

Another variant:

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

trait Trait {}

struct A<T>(T)
where
    [(); size_of::<T>()]:;

fn main() {
    let x: A<dyn Trait>;
}

Error output

error: internal compiler error: compiler/rustc_const_eval/src/interpret/operator.rs:522:21: unsized type for `NullaryOp::SizeOf`
   --> /playground/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/mem/mod.rs:309:5
    |
309 |     intrinsics::size_of::<T>()
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^


thread 'rustc' panicked at compiler/rustc_const_eval/src/interpret/operator.rs:522:21:
Box<dyn Any>
stack backtrace:
   0:     0x74a60ffaae40 - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::he98e11da2daa96a9
   1:     0x74a610814ee6 - core::fmt::write::had177877e89931fb
   2:     0x74a611750b51 - std::io::Write::write_fmt::hc355e6fef9c0a3ce
   3:     0x74a60ffaaca2 - std::sys::backtrace::BacktraceLock::print::h676c1f81be95e0b1
   4:     0x74a60ffad122 - std::panicking::default_hook::{{closure}}::hd28d3669866dc126
   5:     0x74a60ffacfaa - std::panicking::default_hook::h039746809c2c5ae1
   6:     0x74a60f15ff39 - std[644fad426ed526f7]::panicking::update_hook::<alloc[5097d557d6b96634]::boxed::Box<rustc_driver_impl[438371d8e84705cb]::install_ice_hook::{closure#1}>>::{closure#0}
   7:     0x74a60ffadc63 - std::panicking::rust_panic_with_hook::h88108df39d1d1441
   8:     0x74a60f19b421 - std[644fad426ed526f7]::panicking::begin_panic::<rustc_errors[d6afe1f3c80315c7]::ExplicitBug>::{closure#0}
   9:     0x74a60f190326 - std[644fad426ed526f7]::sys::backtrace::__rust_end_short_backtrace::<std[644fad426ed526f7]::panicking::begin_panic<rustc_errors[d6afe1f3c80315c7]::ExplicitBug>::{closure#0}, !>
  10:     0x74a60f18d05d - std[644fad426ed526f7]::panicking::begin_panic::<rustc_errors[d6afe1f3c80315c7]::ExplicitBug>
  11:     0x74a60f1a5351 - <rustc_errors[d6afe1f3c80315c7]::diagnostic::BugAbort as rustc_errors[d6afe1f3c80315c7]::diagnostic::EmissionGuarantee>::emit_producing_guarantee
  12:     0x74a60f703fac - <rustc_errors[d6afe1f3c80315c7]::DiagCtxtHandle>::span_bug::<rustc_span[45d362c5296a3b7f]::span_encoding::Span, alloc[5097d557d6b96634]::string::String>
  13:     0x74a60f786807 - rustc_middle[dfbbc45bb841e134]::util::bug::opt_span_bug_fmt::<rustc_span[45d362c5296a3b7f]::span_encoding::Span>::{closure#0}
  14:     0x74a60f76f7aa - rustc_middle[dfbbc45bb841e134]::ty::context::tls::with_opt::<rustc_middle[dfbbc45bb841e134]::util::bug::opt_span_bug_fmt<rustc_span[45d362c5296a3b7f]::span_encoding::Span>::{closure#0}, !>::{closure#0}
  15:     0x74a60f76f63b - rustc_middle[dfbbc45bb841e134]::ty::context::tls::with_context_opt::<rustc_middle[dfbbc45bb841e134]::ty::context::tls::with_opt<rustc_middle[dfbbc45bb841e134]::util::bug::opt_span_bug_fmt<rustc_span[45d362c5296a3b7f]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
  16:     0x74a60e1bd337 - rustc_middle[dfbbc45bb841e134]::util::bug::span_bug_fmt::<rustc_span[45d362c5296a3b7f]::span_encoding::Span>
  17:     0x74a6113a0995 - <rustc_const_eval[4c73f18587537670]::interpret::eval_context::InterpCx<rustc_const_eval[4c73f18587537670]::const_eval::machine::CompileTimeMachine>>::eval_rvalue_into_place
  18:     0x74a60e1dce39 - rustc_const_eval[4c73f18587537670]::const_eval::eval_queries::eval_to_allocation_raw_provider
  19:     0x74a611012e9c - rustc_query_impl[9923fb681be542d6]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[9923fb681be542d6]::query_impl::eval_to_allocation_raw::dynamic_query::{closure#2}::{closure#0}, rustc_middle[dfbbc45bb841e134]::query::erase::Erased<[u8; 24usize]>>
  20:     0x74a61101283a - rustc_query_system[ea81b1814f2bc579]::query::plumbing::try_execute_query::<rustc_query_impl[9923fb681be542d6]::DynamicConfig<rustc_query_system[ea81b1814f2bc579]::query::caches::DefaultCache<rustc_middle[dfbbc45bb841e134]::ty::PseudoCanonicalInput<rustc_middle[dfbbc45bb841e134]::mir::interpret::GlobalId>, rustc_middle[dfbbc45bb841e134]::query::erase::Erased<[u8; 24usize]>>, false, false, false>, rustc_query_impl[9923fb681be542d6]::plumbing::QueryCtxt, false>
  21:     0x74a6110124bb - rustc_query_impl[9923fb681be542d6]::query_impl::eval_to_allocation_raw::get_query_non_incr::__rust_end_short_backtrace
  22:     0x74a611019d65 - rustc_const_eval[4c73f18587537670]::const_eval::valtrees::eval_to_valtree
  23:     0x74a611019b1c - <rustc_const_eval[4c73f18587537670]::provide::{closure#0} as core[d2a938784d8f7dcb]::ops::function::FnOnce<(rustc_middle[dfbbc45bb841e134]::ty::context::TyCtxt, rustc_middle[dfbbc45bb841e134]::ty::PseudoCanonicalInput<rustc_middle[dfbbc45bb841e134]::mir::interpret::GlobalId>)>>::call_once
  24:     0x74a611019ac6 - rustc_query_impl[9923fb681be542d6]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[9923fb681be542d6]::query_impl::eval_to_valtree::dynamic_query::{closure#2}::{closure#0}, rustc_middle[dfbbc45bb841e134]::query::erase::Erased<[u8; 24usize]>>
  25:     0x74a611019a7f - <rustc_query_impl[9923fb681be542d6]::query_impl::eval_to_valtree::dynamic_query::{closure#2} as core[d2a938784d8f7dcb]::ops::function::FnOnce<(rustc_middle[dfbbc45bb841e134]::ty::context::TyCtxt, rustc_middle[dfbbc45bb841e134]::ty::PseudoCanonicalInput<rustc_middle[dfbbc45bb841e134]::mir::interpret::GlobalId>)>>::call_once
  26:     0x74a611012913 - rustc_query_system[ea81b1814f2bc579]::query::plumbing::try_execute_query::<rustc_query_impl[9923fb681be542d6]::DynamicConfig<rustc_query_system[ea81b1814f2bc579]::query::caches::DefaultCache<rustc_middle[dfbbc45bb841e134]::ty::PseudoCanonicalInput<rustc_middle[dfbbc45bb841e134]::mir::interpret::GlobalId>, rustc_middle[dfbbc45bb841e134]::query::erase::Erased<[u8; 24usize]>>, false, false, false>, rustc_query_impl[9923fb681be542d6]::plumbing::QueryCtxt, false>
  27:     0x74a61101222d - rustc_query_impl[9923fb681be542d6]::query_impl::eval_to_valtree::get_query_non_incr::__rust_end_short_backtrace
  28:     0x74a6113d390c - rustc_middle[dfbbc45bb841e134]::query::plumbing::query_get_at::<rustc_query_system[ea81b1814f2bc579]::query::caches::DefaultCache<rustc_middle[dfbbc45bb841e134]::ty::PseudoCanonicalInput<rustc_middle[dfbbc45bb841e134]::mir::interpret::GlobalId>, rustc_middle[dfbbc45bb841e134]::query::erase::Erased<[u8; 24usize]>>>
  29:     0x74a6113d2f22 - <rustc_middle[dfbbc45bb841e134]::ty::context::TyCtxt>::const_eval_global_id_for_typeck
  30:     0x74a6113d2db9 - <rustc_middle[dfbbc45bb841e134]::ty::context::TyCtxt>::const_eval_resolve_for_typeck
  31:     0x74a6113d2af7 - rustc_trait_selection[a0c4a4c304b8efe3]::traits::try_evaluate_const
  32:     0x74a612494ef8 - rustc_trait_selection[a0c4a4c304b8efe3]::traits::const_evaluatable::is_const_evaluatable.cold
  33:     0x74a6110ee30f - <rustc_trait_selection[a0c4a4c304b8efe3]::traits::fulfill::FulfillProcessor as rustc_data_structures[702a32bac37c74a0]::obligation_forest::ObligationProcessor>::process_obligation
  34:     0x74a610810642 - <rustc_data_structures[702a32bac37c74a0]::obligation_forest::ObligationForest<rustc_trait_selection[a0c4a4c304b8efe3]::traits::fulfill::PendingPredicateObligation>>::process_obligations::<rustc_trait_selection[a0c4a4c304b8efe3]::traits::fulfill::FulfillProcessor>
  35:     0x74a610e49c43 - rustc_hir_typeck[711cb0c541d6273d]::typeck_with_inspect::{closure#0}
  36:     0x74a610e47b8c - rustc_query_impl[9923fb681be542d6]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[9923fb681be542d6]::query_impl::typeck::dynamic_query::{closure#2}::{closure#0}, rustc_middle[dfbbc45bb841e134]::query::erase::Erased<[u8; 8usize]>>
  37:     0x74a610b996ce - rustc_query_system[ea81b1814f2bc579]::query::plumbing::try_execute_query::<rustc_query_impl[9923fb681be542d6]::DynamicConfig<rustc_data_structures[702a32bac37c74a0]::vec_cache::VecCache<rustc_span[45d362c5296a3b7f]::def_id::LocalDefId, rustc_middle[dfbbc45bb841e134]::query::erase::Erased<[u8; 8usize]>, rustc_query_system[ea81b1814f2bc579]::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl[9923fb681be542d6]::plumbing::QueryCtxt, false>
  38:     0x74a610b97bd1 - rustc_query_impl[9923fb681be542d6]::query_impl::typeck::get_query_non_incr::__rust_end_short_backtrace
  39:     0x74a610b9788b - <rustc_middle[dfbbc45bb841e134]::hir::map::Map>::par_body_owners::<rustc_hir_analysis[679b9e311f2f4bbc]::check_crate::{closure#4}>::{closure#0}
  40:     0x74a610b9593f - rustc_hir_analysis[679b9e311f2f4bbc]::check_crate
  41:     0x74a610b91f62 - rustc_interface[68fc4f7f4eaa26cf]::passes::run_required_analyses
  42:     0x74a61174c25e - rustc_interface[68fc4f7f4eaa26cf]::passes::analysis
  43:     0x74a61174c22f - rustc_query_impl[9923fb681be542d6]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[9923fb681be542d6]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[dfbbc45bb841e134]::query::erase::Erased<[u8; 0usize]>>
  44:     0x74a611729855 - rustc_query_system[ea81b1814f2bc579]::query::plumbing::try_execute_query::<rustc_query_impl[9923fb681be542d6]::DynamicConfig<rustc_query_system[ea81b1814f2bc579]::query::caches::SingleCache<rustc_middle[dfbbc45bb841e134]::query::erase::Erased<[u8; 0usize]>>, false, false, false>, rustc_query_impl[9923fb681be542d6]::plumbing::QueryCtxt, false>
  45:     0x74a61172958e - rustc_query_impl[9923fb681be542d6]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  46:     0x74a611765169 - rustc_interface[68fc4f7f4eaa26cf]::passes::create_and_enter_global_ctxt::<core[d2a938784d8f7dcb]::option::Option<rustc_interface[68fc4f7f4eaa26cf]::queries::Linker>, rustc_driver_impl[438371d8e84705cb]::run_compiler::{closure#0}::{closure#2}>::{closure#2}::{closure#0}
  47:     0x74a6117a250a - rustc_interface[68fc4f7f4eaa26cf]::interface::run_compiler::<(), rustc_driver_impl[438371d8e84705cb]::run_compiler::{closure#0}>::{closure#1}
  48:     0x74a61168a875 - std[644fad426ed526f7]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[68fc4f7f4eaa26cf]::util::run_in_thread_with_globals<rustc_interface[68fc4f7f4eaa26cf]::util::run_in_thread_pool_with_globals<rustc_interface[68fc4f7f4eaa26cf]::interface::run_compiler<(), rustc_driver_impl[438371d8e84705cb]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
  49:     0x74a61168a559 - <<std[644fad426ed526f7]::thread::Builder>::spawn_unchecked_<rustc_interface[68fc4f7f4eaa26cf]::util::run_in_thread_with_globals<rustc_interface[68fc4f7f4eaa26cf]::util::run_in_thread_pool_with_globals<rustc_interface[68fc4f7f4eaa26cf]::interface::run_compiler<(), rustc_driver_impl[438371d8e84705cb]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core[d2a938784d8f7dcb]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  50:     0x74a611689ceb - std::sys::pal::unix::thread::Thread::new::thread_start::h6b29fca7c6a267b7
  51:     0x74a612e5aa94 - <unknown>
  52:     0x74a612ee7a34 - clone
  53:                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: please make sure that you have updated to the latest nightly

note: please attach the file at `/playground/rustc-ice-2025-01-28T09_01_54-22.txt` to your bug report

note: compiler flags: --crate-type bin -C embed-bitcode=no -C codegen-units=1 -C debuginfo=2

note: some of the compiler flags provided by cargo are hidden

query stack during panic:
#0 [eval_to_allocation_raw] const-evaluating + checking `A::{constant#0}`
#1 [eval_to_valtree] evaluating type-level constant
... and 2 other queries... use `env RUST_BACKTRACE=1` to see the full query stack
error: could not compile `playground` (bin "playground")