error[E0658]: unsafe binder types are experimental
 --> /tmp/icemaker_global_tempdir.A6IhLPTBdYWO/rustc_testrunner_tmpdir_reporting.6KgdE5XcBCgS/mvce.rs:2:8
  |
2 |     b: unsafe<> (),
  |        ^^^^^^^^^^^
  |
  = note: see issue #130516 <https://github.com/rust-lang/rust/issues/130516> for more information
  = help: add `#![feature(unsafe_binders)]` to the crate attributes to enable
  = note: this compiler was built on 2026-04-06; consider upgrading it if it is out of date


thread 'rustc' (445532) panicked at /rustc-dev/c2efcc4ae006a6b2761cb42572fc9cee0d1ce4af/compiler/rustc_trait_selection/src/traits/project.rs:1129:52:
not yet implemented: FIXME(unsafe_binder)
stack backtrace:
   0:     0x7f0edcbb66ab - <<std[8eed7d2a0d2e32a7]::sys::backtrace::BacktraceLock>::print::DisplayBacktrace as core[c3b3818c781903d6]::fmt::Display>::fmt
   1:     0x7f0edd21d748 - core[c3b3818c781903d6]::fmt::write
   2:     0x7f0edcbcd976 - <std[8eed7d2a0d2e32a7]::sys::stdio::unix::Stderr as std[8eed7d2a0d2e32a7]::io::Write>::write_fmt
   3:     0x7f0edcb8c9a8 - std[8eed7d2a0d2e32a7]::panicking::default_hook::{closure#0}
   4:     0x7f0edcba9d13 - std[8eed7d2a0d2e32a7]::panicking::default_hook
   5:     0x7f0edbbb155c - std[8eed7d2a0d2e32a7]::panicking::update_hook::<alloc[f403ee7a715222b6]::boxed::Box<rustc_driver_impl[7e67e524f2e0558b]::install_ice_hook::{closure#1}>>::{closure#0}
   6:     0x7f0edcba9ff2 - std[8eed7d2a0d2e32a7]::panicking::panic_with_hook
   7:     0x7f0edcb8ca9a - std[8eed7d2a0d2e32a7]::panicking::panic_handler::{closure#0}
   8:     0x7f0edcb837a9 - std[8eed7d2a0d2e32a7]::sys::backtrace::__rust_end_short_backtrace::<std[8eed7d2a0d2e32a7]::panicking::panic_handler::{closure#0}, !>
   9:     0x7f0edcb8e4cd - __rustc[1c0edf6a00b737dc]::rust_begin_unwind
  10:     0x7f0ed9696bfc - core[c3b3818c781903d6]::panicking::panic_fmt
  11:     0x7f0edd45449e - rustc_trait_selection[11b0d89c7a99abb7]::traits::project::opt_normalize_projection_term
  12:     0x7f0edd4563a3 - <rustc_infer[ebc771a24fe05da5]::infer::InferCtxt>::commit_if_ok::<rustc_trait_selection[11b0d89c7a99abb7]::traits::project::ProjectAndUnifyResult, rustc_infer[ebc771a24fe05da5]::traits::project::MismatchedProjectionTypes, rustc_trait_selection[11b0d89c7a99abb7]::traits::project::poly_project_and_unify_term::{closure#0}>
  13:     0x7f0edd78c79a - <rustc_trait_selection[11b0d89c7a99abb7]::traits::select::SelectionContext>::evaluate_predicate_recursively
  14:     0x7f0edd78ee3d - <rustc_trait_selection[11b0d89c7a99abb7]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively
  15:     0x7f0edd779dc2 - <rustc_trait_selection[11b0d89c7a99abb7]::traits::select::SelectionContext>::evaluate_root_obligation
  16:     0x7f0edd777f38 - rustc_traits[606884767d5c0f75]::evaluate_obligation::evaluate_obligation
  17:     0x7f0edd777887 - rustc_query_impl[f409b05e3d872181]::query_impl::evaluate_obligation::invoke_provider_fn::__rust_begin_short_backtrace
  18:     0x7f0edd7769e8 - rustc_query_impl[f409b05e3d872181]::execution::try_execute_query::<rustc_middle[165f22ec1c9787f3]::query::caches::DefaultCache<rustc_type_ir[85c4afa899d1a1b6]::canonical::CanonicalQueryInput<rustc_middle[165f22ec1c9787f3]::ty::context::TyCtxt, rustc_middle[165f22ec1c9787f3]::ty::ParamEnvAnd<rustc_middle[165f22ec1c9787f3]::ty::predicate::Predicate>>, rustc_middle[165f22ec1c9787f3]::query::erase::ErasedData<[u8; 2usize]>>, false>
  19:     0x7f0edd776679 - rustc_query_impl[f409b05e3d872181]::query_impl::evaluate_obligation::execute_query_non_incr::__rust_end_short_backtrace
  20:     0x7f0edd9b0bbd - <rustc_trait_selection[11b0d89c7a99abb7]::traits::fulfill::FulfillProcessor as rustc_data_structures[cae841260e08523c]::obligation_forest::ObligationProcessor>::process_obligation
  21:     0x7f0edd206cd6 - <rustc_data_structures[cae841260e08523c]::obligation_forest::ObligationForest<rustc_trait_selection[11b0d89c7a99abb7]::traits::fulfill::PendingPredicateObligation>>::process_obligations::<rustc_trait_selection[11b0d89c7a99abb7]::traits::fulfill::FulfillProcessor>
  22:     0x7f0ede4dabe1 - rustc_hir_typeck[2782182a00a8d9e]::typeck_with_inspect::{closure#0}
  23:     0x7f0ede4d9470 - rustc_query_impl[f409b05e3d872181]::query_impl::typeck_root::invoke_provider_fn::__rust_begin_short_backtrace
  24:     0x7f0edd2bbe66 - rustc_query_impl[f409b05e3d872181]::execution::try_execute_query::<rustc_data_structures[cae841260e08523c]::vec_cache::VecCache<rustc_span[70fc2dc825ee8976]::def_id::LocalDefId, rustc_middle[165f22ec1c9787f3]::query::erase::ErasedData<[u8; 8usize]>, rustc_middle[165f22ec1c9787f3]::dep_graph::graph::DepNodeIndex>, false>
  25:     0x7f0edd2bb743 - rustc_query_impl[f409b05e3d872181]::query_impl::typeck_root::execute_query_non_incr::__rust_end_short_backtrace
  26:     0x7f0edda19b6c - <rustc_middle[165f22ec1c9787f3]::ty::context::TyCtxt>::par_hir_body_owners::<rustc_hir_analysis[13c6348c6cd39757]::check_crate::{closure#1}>::{closure#0}
  27:     0x7f0edda19565 - rustc_hir_analysis[13c6348c6cd39757]::check_crate
  28:     0x7f0edd2b8561 - rustc_interface[3d73cd67649ddf73]::passes::analysis
  29:     0x7f0ede445149 - rustc_query_impl[f409b05e3d872181]::execution::try_execute_query::<rustc_middle[165f22ec1c9787f3]::query::caches::SingleCache<rustc_middle[165f22ec1c9787f3]::query::erase::ErasedData<[u8; 0usize]>>, false>
  30:     0x7f0ede444db5 - rustc_query_impl[f409b05e3d872181]::query_impl::analysis::execute_query_non_incr::__rust_end_short_backtrace
  31:     0x7f0ede46c15e - rustc_interface[3d73cd67649ddf73]::interface::run_compiler::<(), rustc_driver_impl[7e67e524f2e0558b]::run_compiler::{closure#0}>::{closure#1}
  32:     0x7f0ede41a03e - std[8eed7d2a0d2e32a7]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[3d73cd67649ddf73]::util::run_in_thread_with_globals<rustc_interface[3d73cd67649ddf73]::util::run_in_thread_pool_with_globals<rustc_interface[3d73cd67649ddf73]::interface::run_compiler<(), rustc_driver_impl[7e67e524f2e0558b]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
  33:     0x7f0ede41a8e0 - <std[8eed7d2a0d2e32a7]::thread::lifecycle::spawn_unchecked<rustc_interface[3d73cd67649ddf73]::util::run_in_thread_with_globals<rustc_interface[3d73cd67649ddf73]::util::run_in_thread_pool_with_globals<rustc_interface[3d73cd67649ddf73]::interface::run_compiler<(), rustc_driver_impl[7e67e524f2e0558b]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core[c3b3818c781903d6]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  34:     0x7f0ede41b7ec - <std[8eed7d2a0d2e32a7]::sys::thread::unix::Thread>::new::thread_start
  35:     0x7f0ed7ea097a - <unknown>
  36:     0x7f0ed7f242bc - <unknown>
  37:                0x0 - <unknown>

error: 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: please make sure that you have updated to the latest nightly

note: rustc 1.96.0-nightly (c2efcc4ae 2026-04-06) running on x86_64-unknown-linux-gnu

query stack during panic:
#0 [evaluate_obligation] evaluating trait selection obligation `Struct: core::ptr::metadata::Thin`
#1 [typeck_root] type-checking `main`
#2 [analysis] running analysis passes on crate `mvce`
end of query stack
error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0658`.