ICE with -Zextra-const-ub-checks: normalization works on validated constants

[matthiaskrgr]

code from rustc ./src/test/ui/consts/packed_pattern.rs

// run-pass

#[derive(PartialEq, Eq, Copy, Clone)]
#[repr(packed)]
struct Foo {
    field: (i64, u32, u32, u32),
}

const FOO: Foo = Foo {
    field: (5, 6, 7, 8),
};

fn main() {
    match FOO {
        Foo { field: (5, 6, 7, 8) } => {},
        FOO => unreachable!(), //~ WARNING unreachable pattern
        _ => unreachable!(),
    }
}

this causes a new panic when executed via miri:

Preparing a sysroot for Miri (target: x86_64-unknown-linux-gnu)... done
WARNING: Ignoring `RUSTC_WRAPPER` environment variable, Miri does not support wrapping.
    Finished dev [unoptimized + debuginfo] target(s) in 0.01s
     Running `/home/matthias/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/bin/cargo-miri runner target/miri/x86_64-unknown-linux-gnu/debug/ff`
thread 'rustc' panicked at 'normalization works on validated constants: InterpErrorInfo(InterpErrorInfoInner { kind: accessing memory with alignment 1, but alignment 8 is required, backtrace: None })', compiler/rustc_const_eval/src/const_eval/eval_queries.rs:132:36
stack backtrace:
   0:     0x7fc271d216d0 - std::backtrace_rs::backtrace::libunwind::trace::hdc27bfa6aa97f84d
                               at /rustc/0b79f758c9aa6646606662a6d623a0752286cd17/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   1:     0x7fc271d216d0 - std::backtrace_rs::backtrace::trace_unsynchronized::hd260a87da0307fa5
                               at /rustc/0b79f758c9aa6646606662a6d623a0752286cd17/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7fc271d216d0 - std::sys_common::backtrace::_print_fmt::h789cb96c4a337f2c
                               at /rustc/0b79f758c9aa6646606662a6d623a0752286cd17/library/std/src/sys_common/backtrace.rs:66:5
   3:     0x7fc271d216d0 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h36bc3de3612a60f5
                               at /rustc/0b79f758c9aa6646606662a6d623a0752286cd17/library/std/src/sys_common/backtrace.rs:45:22
   4:     0x7fc271d7c76e - core::fmt::write::h2db4bfe92ef037b0
                               at /rustc/0b79f758c9aa6646606662a6d623a0752286cd17/library/core/src/fmt/mod.rs:1202:17
   5:     0x7fc271d124d5 - std::io::Write::write_fmt::hcd345fc714a96537
                               at /rustc/0b79f758c9aa6646606662a6d623a0752286cd17/library/std/src/io/mod.rs:1672:15
   6:     0x7fc271d24393 - std::sys_common::backtrace::_print::hcf53c28899e66110
                               at /rustc/0b79f758c9aa6646606662a6d623a0752286cd17/library/std/src/sys_common/backtrace.rs:48:5
   7:     0x7fc271d24393 - std::sys_common::backtrace::print::hd8ec3e1ae139ef7a
                               at /rustc/0b79f758c9aa6646606662a6d623a0752286cd17/library/std/src/sys_common/backtrace.rs:35:9
   8:     0x7fc271d24393 - std::panicking::default_hook::{{closure}}::he70b99e2f9e5bd44
                               at /rustc/0b79f758c9aa6646606662a6d623a0752286cd17/library/std/src/panicking.rs:295:22
   9:     0x7fc271d2407f - std::panicking::default_hook::h8d91a23b91011754
                               at /rustc/0b79f758c9aa6646606662a6d623a0752286cd17/library/std/src/panicking.rs:314:9
  10:     0x7fc274563644 - <rustc_driver[d9adb13473fd7853]::DEFAULT_HOOK::{closure#0}::{closure#0} as core[97bb3a13db18d0cb]::ops::function::FnOnce<(&core[97bb3a13db18d0cb]::panic::panic_info::PanicInfo,)>>::call_once::{shim:vtable#0}
  11:     0x7fc271d24bcd - std::panicking::rust_panic_with_hook::h5af783bc1124b2c1
                               at /rustc/0b79f758c9aa6646606662a6d623a0752286cd17/library/std/src/panicking.rs:702:17
  12:     0x7fc271d24a27 - std::panicking::begin_panic_handler::{{closure}}::h234d8ef84a25d2ee
                               at /rustc/0b79f758c9aa6646606662a6d623a0752286cd17/library/std/src/panicking.rs:588:13
  13:     0x7fc271d21bdc - std::sys_common::backtrace::__rust_end_short_backtrace::he0cdebe1a4227e87
                               at /rustc/0b79f758c9aa6646606662a6d623a0752286cd17/library/std/src/sys_common/backtrace.rs:138:18
  14:     0x7fc271d24742 - rust_begin_unwind
                               at /rustc/0b79f758c9aa6646606662a6d623a0752286cd17/library/std/src/panicking.rs:584:5
  15:     0x7fc271d79283 - core::panicking::panic_fmt::hfb889492842f4bec
                               at /rustc/0b79f758c9aa6646606662a6d623a0752286cd17/library/core/src/panicking.rs:142:14
  16:     0x7fc271d795e3 - core::result::unwrap_failed::hecfa3811d2c0fa35
                               at /rustc/0b79f758c9aa6646606662a6d623a0752286cd17/library/core/src/result.rs:1814:5
  17:     0x7fc273f6346e - rustc_const_eval[22f532cf3fc8f4c3]::const_eval::eval_queries::op_to_const
  18:     0x7fc27414d4d0 - <alloc[d0a20223ecbdb9c4]::vec::Vec<rustc_middle[151dce3d5e114089]::mir::ConstantKind> as alloc[d0a20223ecbdb9c4]::vec::spec_from_iter::SpecFromIter<rustc_middle[151dce3d5e114089]::mir::ConstantKind, core[97bb3a13db18d0cb]::iter::adapters::GenericShunt<core[97bb3a13db18d0cb]::iter::adapters::map::Map<core[97bb3a13db18d0cb]::ops::range::Range<usize>, rustc_const_eval[22f532cf3fc8f4c3]::const_eval::try_destructure_mir_constant::{closure#0}>, core[97bb3a13db18d0cb]::result::Result<core[97bb3a13db18d0cb]::convert::Infallible, rustc_middle[151dce3d5e114089]::mir::interpret::error::InterpErrorInfo>>>>::from_iter
  19:     0x7fc274234066 - rustc_const_eval[22f532cf3fc8f4c3]::const_eval::try_destructure_mir_constant
  20:     0x7fc274233dd7 - <rustc_const_eval[22f532cf3fc8f4c3]::provide::{closure#1} as core[97bb3a13db18d0cb]::ops::function::FnOnce<(rustc_middle[151dce3d5e114089]::ty::context::TyCtxt, rustc_middle[151dce3d5e114089]::ty::ParamEnvAnd<rustc_middle[151dce3d5e114089]::mir::ConstantKind>)>>::call_once
  21:     0x7fc27423ad2c - <rustc_query_system[2040a19449a5eda6]::dep_graph::graph::DepGraph<rustc_middle[151dce3d5e114089]::dep_graph::dep_node::DepKind>>::with_task::<rustc_middle[151dce3d5e114089]::ty::context::TyCtxt, rustc_middle[151dce3d5e114089]::ty::ParamEnvAnd<rustc_middle[151dce3d5e114089]::mir::ConstantKind>, core[97bb3a13db18d0cb]::option::Option<rustc_middle[151dce3d5e114089]::mir::query::DestructuredMirConstant>>
  22:     0x7fc2742398a1 - rustc_query_system[2040a19449a5eda6]::query::plumbing::get_query::<rustc_query_impl[b271cbf8bf993093]::queries::try_destructure_mir_constant, rustc_query_impl[b271cbf8bf993093]::plumbing::QueryCtxt>
  23:     0x7fc274238eed - <rustc_query_impl[b271cbf8bf993093]::Queries as rustc_middle[151dce3d5e114089]::ty::query::QueryEngine>::try_destructure_mir_constant
  24:     0x7fc273141dc6 - <rustc_middle[151dce3d5e114089]::ty::context::TyCtxt>::destructure_mir_constant
  25:     0x7fc27313e7ce - <rustc_mir_build[362d32de073b060d]::thir::pattern::const_to_pat::ConstToPat>::recur
  26:     0x7fc273142e7f - <core[97bb3a13db18d0cb]::iter::adapters::copied::Copied<core[97bb3a13db18d0cb]::slice::iter::Iter<rustc_middle[151dce3d5e114089]::mir::ConstantKind>> as core[97bb3a13db18d0cb]::iter::traits::iterator::Iterator>::try_fold::<(), <core[97bb3a13db18d0cb]::iter::adapters::enumerate::Enumerate<_> as core[97bb3a13db18d0cb]::iter::traits::iterator::Iterator>::try_fold::enumerate<rustc_middle[151dce3d5e114089]::mir::ConstantKind, (), core[97bb3a13db18d0cb]::ops::control_flow::ControlFlow<core[97bb3a13db18d0cb]::ops::control_flow::ControlFlow<rustc_middle[151dce3d5e114089]::thir::FieldPat>>, core[97bb3a13db18d0cb]::iter::adapters::map::map_try_fold<(usize, rustc_middle[151dce3d5e114089]::mir::ConstantKind), core[97bb3a13db18d0cb]::result::Result<rustc_middle[151dce3d5e114089]::thir::FieldPat, rustc_mir_build[362d32de073b060d]::thir::pattern::const_to_pat::fallback_to_const_ref::FallbackToConstRef>, (), core[97bb3a13db18d0cb]::ops::control_flow::ControlFlow<core[97bb3a13db18d0cb]::ops::control_flow::ControlFlow<rustc_middle[151dce3d5e114089]::thir::FieldPat>>, <rustc_mir_build[362d32de073b060d]::thir::pattern::const_to_pat::ConstToPat>::field_pats<core[97bb3a13db18d0cb]::iter::adapters::copied::Copied<core[97bb3a13db18d0cb]::slice::iter::Iter<rustc_middle[151dce3d5e114089]::mir::ConstantKind>>>::{closure#0}, <core[97bb3a13db18d0cb]::iter::adapters::GenericShunt<core[97bb3a13db18d0cb]::iter::adapters::map::Map<core[97bb3a13db18d0cb]::iter::adapters::enumerate::Enumerate<core[97bb3a13db18d0cb]::iter::adapters::copied::Copied<core[97bb3a13db18d0cb]::slice::iter::Iter<rustc_middle[151dce3d5e114089]::mir::ConstantKind>>>, <rustc_mir_build[362d32de073b060d]::thir::pattern::const_to_pat::ConstToPat>::field_pats<core[97bb3a13db18d0cb]::iter::adapters::copied::Copied<core[97bb3a13db18d0cb]::slice::iter::Iter<rustc_middle[151dce3d5e114089]::mir::ConstantKind>>>::{closure#0}>, core[97bb3a13db18d0cb]::result::Result<core[97bb3a13db18d0cb]::convert::Infallible, rustc_mir_build[362d32de073b060d]::thir::pattern::const_to_pat::fallback_to_const_ref::FallbackToConstRef>> as core[97bb3a13db18d0cb]::iter::traits::iterator::Iterator>::try_fold<(), core[97bb3a13db18d0cb]::iter::traits::iterator::Iterator::try_for_each::call<rustc_middle[151dce3d5e114089]::thir::FieldPat, core[97bb3a13db18d0cb]::ops::control_flow::ControlFlow<rustc_middle[151dce3d5e114089]::thir::FieldPat>, core[97bb3a13db18d0cb]::ops::control_flow::ControlFlow<rustc_middle[151dce3d5e114089]::thir::FieldPat>::Break>::{closure#0}, core[97bb3a13db18d0cb]::ops::control_flow::ControlFlow<rustc_middle[151dce3d5e114089]::thir::FieldPat>>::{closure#0}>::{closure#0}>::{closure#0}, core[97bb3a13db18d0cb]::ops::control_flow::ControlFlow<core[97bb3a13db18d0cb]::ops::control_flow::ControlFlow<rustc_middle[151dce3d5e114089]::thir::FieldPat>>>
  27:     0x7fc273142b8b - <alloc[d0a20223ecbdb9c4]::vec::Vec<rustc_middle[151dce3d5e114089]::thir::FieldPat> as alloc[d0a20223ecbdb9c4]::vec::spec_from_iter::SpecFromIter<rustc_middle[151dce3d5e114089]::thir::FieldPat, core[97bb3a13db18d0cb]::iter::adapters::GenericShunt<core[97bb3a13db18d0cb]::iter::adapters::map::Map<core[97bb3a13db18d0cb]::iter::adapters::enumerate::Enumerate<core[97bb3a13db18d0cb]::iter::adapters::copied::Copied<core[97bb3a13db18d0cb]::slice::iter::Iter<rustc_middle[151dce3d5e114089]::mir::ConstantKind>>>, <rustc_mir_build[362d32de073b060d]::thir::pattern::const_to_pat::ConstToPat>::field_pats<core[97bb3a13db18d0cb]::iter::adapters::copied::Copied<core[97bb3a13db18d0cb]::slice::iter::Iter<rustc_middle[151dce3d5e114089]::mir::ConstantKind>>>::{closure#0}>, core[97bb3a13db18d0cb]::result::Result<core[97bb3a13db18d0cb]::convert::Infallible, rustc_mir_build[362d32de073b060d]::thir::pattern::const_to_pat::fallback_to_const_ref::FallbackToConstRef>>>>::from_iter
  28:     0x7fc27313e817 - <rustc_mir_build[362d32de073b060d]::thir::pattern::const_to_pat::ConstToPat>::recur
  29:     0x7fc27313ce88 - <rustc_mir_build[362d32de073b060d]::thir::pattern::const_to_pat::ConstToPat>::to_pat
  30:     0x7fc27313c9be - <rustc_infer[f3ddb3e777d10305]::infer::InferCtxtBuilder>::enter::<rustc_middle[151dce3d5e114089]::thir::Pat, <rustc_mir_build[362d32de073b060d]::thir::pattern::PatCtxt>::const_to_pat::{closure#0}>
  31:     0x7fc27313c065 - <rustc_mir_build[362d32de073b060d]::thir::pattern::PatCtxt>::const_to_pat
  32:     0x7fc27313a909 - <rustc_mir_build[362d32de073b060d]::thir::pattern::PatCtxt>::lower_path
  33:     0x7fc273138218 - <rustc_mir_build[362d32de073b060d]::thir::pattern::PatCtxt>::lower_pattern
  34:     0x7fc2731f6c51 - <core[97bb3a13db18d0cb]::iter::adapters::map::Map<core[97bb3a13db18d0cb]::slice::iter::Iter<rustc_hir[15bf1790e6da2d76]::hir::Arm>, <rustc_mir_build[362d32de073b060d]::thir::pattern::check_match::MatchVisitor>::check_match::{closure#0}> as core[97bb3a13db18d0cb]::iter::traits::iterator::Iterator>::fold::<(), core[97bb3a13db18d0cb]::iter::traits::iterator::Iterator::for_each::call<rustc_mir_build[362d32de073b060d]::thir::pattern::usefulness::MatchArm, <alloc[d0a20223ecbdb9c4]::vec::Vec<rustc_mir_build[362d32de073b060d]::thir::pattern::usefulness::MatchArm> as alloc[d0a20223ecbdb9c4]::vec::spec_extend::SpecExtend<rustc_mir_build[362d32de073b060d]::thir::pattern::usefulness::MatchArm, core[97bb3a13db18d0cb]::iter::adapters::map::Map<core[97bb3a13db18d0cb]::slice::iter::Iter<rustc_hir[15bf1790e6da2d76]::hir::Arm>, <rustc_mir_build[362d32de073b060d]::thir::pattern::check_match::MatchVisitor>::check_match::{closure#0}>>>::spec_extend::{closure#0}>::{closure#0}>
  35:     0x7fc2731f6b4e - <alloc[d0a20223ecbdb9c4]::vec::Vec<rustc_mir_build[362d32de073b060d]::thir::pattern::usefulness::MatchArm> as alloc[d0a20223ecbdb9c4]::vec::spec_from_iter::SpecFromIter<rustc_mir_build[362d32de073b060d]::thir::pattern::usefulness::MatchArm, core[97bb3a13db18d0cb]::iter::adapters::map::Map<core[97bb3a13db18d0cb]::slice::iter::Iter<rustc_hir[15bf1790e6da2d76]::hir::Arm>, <rustc_mir_build[362d32de073b060d]::thir::pattern::check_match::MatchVisitor>::check_match::{closure#0}>>>::from_iter
  36:     0x7fc2731f3e27 - <rustc_mir_build[362d32de073b060d]::thir::pattern::check_match::MatchVisitor as rustc_hir[15bf1790e6da2d76]::intravisit::Visitor>::visit_expr
  37:     0x7fc2731f3a42 - <rustc_mir_build[362d32de073b060d]::thir::pattern::check_match::MatchVisitor as rustc_hir[15bf1790e6da2d76]::intravisit::Visitor>::visit_expr
  38:     0x7fc27388420a - rustc_mir_build[362d32de073b060d]::thir::pattern::check_match::check_match
  39:     0x7fc2739a1697 - <rustc_query_system[2040a19449a5eda6]::dep_graph::graph::DepGraph<rustc_middle[151dce3d5e114089]::dep_graph::dep_node::DepKind>>::with_task::<rustc_middle[151dce3d5e114089]::ty::context::TyCtxt, rustc_span[8d4f92e92ba5c24b]::def_id::DefId, ()>
  40:     0x7fc2739a06ea - rustc_query_system[2040a19449a5eda6]::query::plumbing::try_execute_query::<rustc_query_impl[b271cbf8bf993093]::plumbing::QueryCtxt, rustc_query_system[2040a19449a5eda6]::query::caches::DefaultCache<rustc_span[8d4f92e92ba5c24b]::def_id::DefId, ()>>
  41:     0x7fc274465280 - <rustc_query_impl[b271cbf8bf993093]::Queries as rustc_middle[151dce3d5e114089]::ty::query::QueryEngine>::check_match
  42:     0x7fc273f38046 - rustc_data_structures[74351d4872850dbb]::sync::par_for_each_in::<&[rustc_span[8d4f92e92ba5c24b]::def_id::LocalDefId], <rustc_middle[151dce3d5e114089]::hir::map::Map>::par_body_owners<rustc_interface[67a969eeca26ae2c]::passes::analysis::{closure#1}::{closure#0}::{closure#0}::{closure#0}>::{closure#0}>
  43:     0x7fc273f378fb - <rustc_middle[151dce3d5e114089]::hir::map::Map>::par_body_owners::<rustc_interface[67a969eeca26ae2c]::passes::analysis::{closure#1}::{closure#0}::{closure#0}::{closure#0}>
  44:     0x7fc273f37693 - <rustc_session[a8a0b865530ef14d]::session::Session>::time::<(), rustc_interface[67a969eeca26ae2c]::passes::analysis::{closure#1}>
  45:     0x7fc273f367ee - rustc_interface[67a969eeca26ae2c]::passes::analysis
  46:     0x7fc2742fbfa2 - <rustc_query_system[2040a19449a5eda6]::dep_graph::graph::DepGraph<rustc_middle[151dce3d5e114089]::dep_graph::dep_node::DepKind>>::with_task::<rustc_middle[151dce3d5e114089]::ty::context::TyCtxt, (), core[97bb3a13db18d0cb]::result::Result<(), rustc_errors[713e2db940a8ff0d]::ErrorGuaranteed>>
  47:     0x7fc2742fb727 - rustc_query_system[2040a19449a5eda6]::query::plumbing::try_execute_query::<rustc_query_impl[b271cbf8bf993093]::plumbing::QueryCtxt, rustc_query_system[2040a19449a5eda6]::query::caches::DefaultCache<(), core[97bb3a13db18d0cb]::result::Result<(), rustc_errors[713e2db940a8ff0d]::ErrorGuaranteed>>>
  48:     0x7fc2742fb21e - rustc_query_system[2040a19449a5eda6]::query::plumbing::get_query::<rustc_query_impl[b271cbf8bf993093]::queries::analysis, rustc_query_impl[b271cbf8bf993093]::plumbing::QueryCtxt>
  49:     0x7fc273d3ec0e - <rustc_interface[67a969eeca26ae2c]::passes::QueryContext>::enter::<rustc_driver[d9adb13473fd7853]::run_compiler::{closure#1}::{closure#2}::{closure#3}, core[97bb3a13db18d0cb]::result::Result<(), rustc_errors[713e2db940a8ff0d]::ErrorGuaranteed>>
  50:     0x7fc273d3a6ce - <rustc_interface[67a969eeca26ae2c]::interface::Compiler>::enter::<rustc_driver[d9adb13473fd7853]::run_compiler::{closure#1}::{closure#2}, core[97bb3a13db18d0cb]::result::Result<core[97bb3a13db18d0cb]::option::Option<rustc_interface[67a969eeca26ae2c]::queries::Linker>, rustc_errors[713e2db940a8ff0d]::ErrorGuaranteed>>
  51:     0x7fc273d361bc - rustc_span[8d4f92e92ba5c24b]::with_source_map::<core[97bb3a13db18d0cb]::result::Result<(), rustc_errors[713e2db940a8ff0d]::ErrorGuaranteed>, rustc_interface[67a969eeca26ae2c]::interface::create_compiler_and_run<core[97bb3a13db18d0cb]::result::Result<(), rustc_errors[713e2db940a8ff0d]::ErrorGuaranteed>, rustc_driver[d9adb13473fd7853]::run_compiler::{closure#1}>::{closure#1}>
  52:     0x7fc273d35ba2 - rustc_interface[67a969eeca26ae2c]::interface::create_compiler_and_run::<core[97bb3a13db18d0cb]::result::Result<(), rustc_errors[713e2db940a8ff0d]::ErrorGuaranteed>, rustc_driver[d9adb13473fd7853]::run_compiler::{closure#1}>
  53:     0x7fc273d34741 - <scoped_tls[e4311800d1c0ff57]::ScopedKey<rustc_span[8d4f92e92ba5c24b]::SessionGlobals>>::set::<rustc_interface[67a969eeca26ae2c]::interface::run_compiler<core[97bb3a13db18d0cb]::result::Result<(), rustc_errors[713e2db940a8ff0d]::ErrorGuaranteed>, rustc_driver[d9adb13473fd7853]::run_compiler::{closure#1}>::{closure#0}, core[97bb3a13db18d0cb]::result::Result<(), rustc_errors[713e2db940a8ff0d]::ErrorGuaranteed>>
  54:     0x7fc273d3442f - std[e5af5fec29962f4a]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[67a969eeca26ae2c]::util::run_in_thread_pool_with_globals<rustc_interface[67a969eeca26ae2c]::interface::run_compiler<core[97bb3a13db18d0cb]::result::Result<(), rustc_errors[713e2db940a8ff0d]::ErrorGuaranteed>, rustc_driver[d9adb13473fd7853]::run_compiler::{closure#1}>::{closure#0}, core[97bb3a13db18d0cb]::result::Result<(), rustc_errors[713e2db940a8ff0d]::ErrorGuaranteed>>::{closure#0}, core[97bb3a13db18d0cb]::result::Result<(), rustc_errors[713e2db940a8ff0d]::ErrorGuaranteed>>
  55:     0x7fc27438ae79 - <<std[e5af5fec29962f4a]::thread::Builder>::spawn_unchecked_<rustc_interface[67a969eeca26ae2c]::util::run_in_thread_pool_with_globals<rustc_interface[67a969eeca26ae2c]::interface::run_compiler<core[97bb3a13db18d0cb]::result::Result<(), rustc_errors[713e2db940a8ff0d]::ErrorGuaranteed>, rustc_driver[d9adb13473fd7853]::run_compiler::{closure#1}>::{closure#0}, core[97bb3a13db18d0cb]::result::Result<(), rustc_errors[713e2db940a8ff0d]::ErrorGuaranteed>>::{closure#0}, core[97bb3a13db18d0cb]::result::Result<(), rustc_errors[713e2db940a8ff0d]::ErrorGuaranteed>>::{closure#1} as core[97bb3a13db18d0cb]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  56:     0x7fc271d2e9c3 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h374ee76b025338a5
                               at /rustc/0b79f758c9aa6646606662a6d623a0752286cd17/library/alloc/src/boxed.rs:1935:9
  57:     0x7fc271d2e9c3 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h2bee731a5ba86295
                               at /rustc/0b79f758c9aa6646606662a6d623a0752286cd17/library/alloc/src/boxed.rs:1935:9
  58:     0x7fc271d2e9c3 - std::sys::unix::thread::Thread::new::thread_start::h44c172ae3f11ec1f
                               at /rustc/0b79f758c9aa6646606662a6d623a0752286cd17/library/std/src/sys/unix/thread.rs:108:17
  59:     0x7fc27198d78d - <unknown>
  60:     0x7fc271a0e8e4 - clone
  61:                0x0 - <unknown>

error: internal compiler error: unexpected panic

note: the compiler unexpectedly panicked. this is a bug.

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 1.65.0-nightly (0b79f758c 2022-08-18) running on x86_64-unknown-linux-gnu

note: compiler flags: --crate-type bin -C embed-bitcode=no -C debuginfo=2 -C incremental -C target-cpu=native

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

query stack during panic:
#0 [try_destructure_mir_constant] destructuring mir constant
rust-lang/miri#1 [check_match] match-checki

[RalfJung]

Ah, there was a reason why we disabled alignment checks in CTFE... This can probably be reproduced without Miri by passing -Zextra-const-ub-checks to rustc.

[matthiaskrgr]

Yeah this just need "cargo miri run", no additional flags required.
Edit: oops, misread 😅

[matthiaskrgr]

Right, this does also reproduce with rustc -Zextra-const-ub-checks. Do you want to move the issue?

[RalfJung]

Yeah let's move this to the rustc repo.