Affected Rust versions: rustc 1.23.0 (766bd11c8 2018-01-01) rustc 1.25.0-nightly (3d292b793 2018-02-03) [Minimal example.](https://github.com/panicbit/rust_issue_48010) ~~(Doesn't seem to trigger on the playground for some reason.)~~ Doesn't trigger when being compiled as binary crate. [Playground version.](http://play.rust-lang.org/?gist=d633689005c5589271c850867516b2b7&version=stable&mode=debug&edition=2015) ``` error: internal compiler error: librustc_trans/context.rs:471: failed to get layout for `&Path<Foo>`: the type `<Foo as Bar>::Slice` has an unknown layout thread 'rustc' panicked at 'Box<Any>', librustc_errors/lib.rs:535:9 note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace. stack backtrace: 0: std::sys::unix::backtrace::tracing::imp::unwind_backtrace at libstd/sys/unix/backtrace/tracing/gcc_s.rs:49 1: std::sys_common::backtrace::print at libstd/sys_common/backtrace.rs:71 at libstd/sys_common/backtrace.rs:59 2: std::panicking::default_hook::{{closure}} at libstd/panicking.rs:380 3: std::panicking::default_hook at libstd/panicking.rs:396 4: std::panicking::rust_panic_with_hook at libstd/panicking.rs:576 5: std::panicking::begin_panic 6: rustc_errors::Handler::bug 7: <std::thread::local::LocalKey<T>>::with 8: rustc::ty::context::tls::with_opt 9: rustc::session::opt_span_bug_fmt 10: rustc::session::bug_fmt 11: <&'a rustc_trans::context::CodegenCx<'a, 'tcx> as rustc::ty::layout::LayoutOf<&'tcx rustc::ty::TyS<'tcx>>>::layout_of 12: rustc_trans::abi::FnType::unadjusted::{{closure}} 13: <alloc::vec::Vec<T> as alloc::vec::SpecExtend<T, I>>::from_iter 14: rustc_trans::abi::FnType::unadjusted 15: rustc_trans::declare::declare_fn 16: rustc_trans::trans_item::predefine_fn 17: rustc_trans::trans_item::MonoItemExt::predefine 18: rustc_trans::base::compile_codegen_unit 19: rustc::ty::maps::<impl rustc::ty::maps::queries::compile_codegen_unit<'tcx>>::compute_result 20: rustc::dep_graph::graph::DepGraph::with_task_impl 21: rustc_errors::Handler::track_diagnostics 22: rustc::ty::maps::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::cycle_check 23: rustc::ty::maps::<impl rustc::ty::maps::queries::compile_codegen_unit<'tcx>>::force 24: rustc::ty::maps::<impl rustc::ty::maps::queries::compile_codegen_unit<'tcx>>::try_get 25: rustc::ty::maps::TyCtxtAt::compile_codegen_unit 26: rustc::ty::maps::<impl rustc::ty::context::TyCtxt<'a, 'tcx, 'lcx>>::compile_codegen_unit 27: rustc_trans::base::trans_crate 28: <rustc_trans::LlvmTransCrate as rustc_trans_utils::trans_crate::TransCrate>::trans_crate 29: rustc::util::common::time 30: rustc_driver::driver::phase_4_translate_to_llvm 31: rustc_driver::driver::compile_input::{{closure}} 32: <std::thread::local::LocalKey<T>>::with 33: <std::thread::local::LocalKey<T>>::with 34: rustc::ty::context::TyCtxt::create_and_enter 35: rustc_driver::driver::compile_input 36: rustc_driver::run_compiler ```