ICE when using impl Iterator<Item = &'a Path> + 'a

[linclelinkpart5]

impl MediaLibrary{
    // ..........
    pub fn meta_fps_from_item_fp<'a, P: Into<PathBuf> + 'a>(&'a self, abs_item_path: P) -> impl Iterator<Item = &'a Path> + 'a {
        // Dummy fixture to make sure this is a generator.
        let closure = move || {
            if false {
                yield Path::new("foo.txt")
            }

            // Empty for loop, compiled here just to check if my code was correct.
            // ICE occurred after adding this loop.
            for meta_target in self.meta_targets {

            }
        };
        gen_to_iter(closure)
    }
}

^ I tried compiling this snippet of code (as part of a cargo test invocation, specifically), and got the following ICE:

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/blob/master/CONTRIBUTING.md#bug-reports

note: rustc 1.23.0-nightly (827cb0d61 2017-11-26) running on x86_64-unknown-linux-gnu

note: run with `RUST_BACKTRACE=1` for a backtrace

thread 'rustc' panicked at 'called `Result::unwrap()` on an `Err` value: (MoveData { move_paths: [MovePath { lvalue: _0 }, MovePath { first_child: mp24, lvalue: _1 }, MovePath { lvalue: _2 }, MovePath { lvalue: _3 }, MovePath { lvalue: _4 }, MovePath { lvalue: _5 }, MovePath { lvalue: _6 }, MovePath { lvalue: _7 }, MovePath { lvalue: _8 }, MovePath { lvalue: _9 }, MovePath { lvalue: _10 }, MovePath { lvalue: _11 }, MovePath { lvalue: _12 }, MovePath { first_child: mp25, lvalue: _13 }, MovePath { lvalue: _14 }, MovePath { lvalue: _15 }, MovePath { lvalue: _16 }, MovePath { lvalue: _17 }, MovePath { lvalue: _18 }, MovePath { lvalue: _19 }, MovePath { lvalue: _20 }, MovePath { lvalue: _21 }, MovePath { lvalue: _22 }, MovePath { lvalue: _23 }, MovePath { parent: mp1, lvalue: (_1.0: &'a library::MediaLibrary) }, MovePath { parent: mp13, first_child: mp26, lvalue: (_13 as Some) }, MovePath { parent: mp25, lvalue: ((_13 as Some).0: library::MetaTarget) }], moves: [mp4@bb3[0], mp1@bb5[0], mp3@bb6[1], mp5@bb6[2], mp1@bb7[0], mp8@bb9[4], mp8@bb10[0], mp8@bb11[0], mp7@bb12[0], mp8@bb13[0], mp7@bb15[1], mp14@bb16[6], mp14@bb17[0], mp9@bb18[0], mp11@bb19[0], mp16@bb20[1], mp26@bb25[1], mp16@bb25[3], mp18@bb25[4], mp18@bb26[0], mp13@bb27[0], mp16@bb28[0], mp18@bb29[0], mp18@bb30[0], mp16@bb30[1], mp16@bb31[0], mp13@bb31[1], mp13@bb32[0], mp15@bb32[1], mp11@bb32[2], mp11@bb33[0], mp9@bb33[1], mp16@bb34[0], mp13@bb34[1], mp13@bb35[0], mp15@bb35[1], mp11@bb35[4], mp21@bb35[5], mp21@bb35[6], mp21@bb36[0], mp20@bb36[3], mp20@bb37[0], mp11@bb37[1], mp11@bb38[0], mp9@bb39[0], mp7@bb39[1], mp7@bb40[0], mp23@bb40[4], mp6@bb40[5], mp1@bb40[6]], loc_map: LocationMap { map: [[[]], [[], [], [], [], [], []], [[], []], [[mo0], []], [[]], [[mo1]], [[], [mo2], [mo3], []], [[mo4]], [[]], [[], [], [], [], [mo5]], [[mo6]], [[mo7]], [[mo8]], [[mo9], []], [[]], [[], [mo10], []], [[], [], [], [], [], [], [mo11]], [[mo12], [], []], [[mo13]], [[mo14]], [[], [mo15]], [[]], [[]], [[]], [[]], [[], [mo16], [], [mo17], [mo18]], [[mo19]], [[mo20]], [[mo21]], [[mo22]], [[mo23], [mo24]], [[mo25], [mo26]], [[mo27], [mo28], [mo29]], [[mo30], [mo31]], [[mo32], [mo33]], [[mo34], [mo35], [], [], [mo36], [mo37], [mo38]], [[mo39], [], [], [mo40]], [[mo41], [mo42]], [[mo43], []], [[mo44], [mo45]], [[mo46], [], [], [], [mo47], [mo48], [mo49]], [[]]] }, path_map: [[], [mo1, mo4, mo49], [], [mo2], [mo0], [mo3], [mo48], [mo8, mo10, mo45, mo46], [mo5, mo6, mo7, mo9], [mo13, mo31, mo44], [], [mo14, mo29, mo30, mo36, mo42, mo43], [], [mo20, mo26, mo27, mo33, mo34], [mo11, mo12], [mo28, mo35], [mo15, mo17, mo21, mo24, mo25, mo32], [], [mo18, mo19, mo22, mo23], [], [mo40, mo41], [mo37, mo38, mo39], [], [mo47], [], [], [mo16]], rev_lookup: MovePathLookup { locals: [mp0, mp1, mp2, mp3, mp4, mp5, mp6, mp7, mp8, mp9, mp10, mp11, mp12, mp13, mp14, mp15, mp16, mp17, mp18, mp19, mp20, mp21, mp22, mp23], projections: {(mp25, Field(field[0], AbstractType)): mp26, (mp1, Field(field[0], AbstractType)): mp24, (mp13, Downcast(std::option::Option, 1)): mp25} } }, [IllegalMove { cannot_move_out_of: IllegalMoveOrigin { span: src/library.rs:210:32: 210:49, kind: BorrowedContent } }])', /checkout/src/libcore/result.rs:906:4
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 /checkout/src/libstd/sys/unix/backtrace/tracing/gcc_s.rs:49
   1: std::sys_common::backtrace::print
             at /checkout/src/libstd/sys_common/backtrace.rs:68
             at /checkout/src/libstd/sys_common/backtrace.rs:57
   2: _ZN3std9panicking12default_hook28_$u7b$$u7b$closure$u7d$$u7d$17h246e98e86e2934d1E.llvm.5A8AA348
             at /checkout/src/libstd/panicking.rs:381
   3: _ZN3std9panicking12default_hook17h46552aebd4a65fe4E.llvm.5A8AA348
             at /checkout/src/libstd/panicking.rs:391
   4: std::panicking::rust_panic_with_hook
             at /checkout/src/libstd/panicking.rs:577
   5: _ZN3std9panicking11begin_panic17he08ceb6b4902de71E.llvm.5A8AA348
             at /checkout/src/libstd/panicking.rs:538
   6: std::panicking::begin_panic_fmt
             at /checkout/src/libstd/panicking.rs:522
   7: rust_begin_unwind
             at /checkout/src/libstd/panicking.rs:498
   8: core::panicking::panic_fmt
             at /checkout/src/libcore/panicking.rs:71
   9: core::result::unwrap_failed
  10: <rustc_mir::transform::elaborate_drops::ElaborateDrops as rustc_mir::transform::MirPass>::run_pass
  11: _ZN9rustc_mir9transform13optimized_mir28_$u7b$$u7b$closure$u7d$$u7d$17hf4e2fe79d7e904ebE.llvm.1C47F73D
  12: rustc_mir::transform::optimized_mir
  13: rustc::ty::maps::<impl rustc::ty::maps::queries::optimized_mir<'tcx>>::compute_result
  14: _ZN5rustc9dep_graph5graph8DepGraph14with_task_impl17h50e0c5cde2c42781E.llvm.9B8CD3D8
  15: rustc_errors::Handler::track_diagnostics
  16: rustc::ty::maps::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::cycle_check
  17: rustc::ty::maps::<impl rustc::ty::maps::queries::optimized_mir<'tcx>>::force
  18: rustc::ty::maps::<impl rustc::ty::maps::queries::optimized_mir<'tcx>>::try_get
  19: rustc::ty::maps::TyCtxtAt::optimized_mir
  20: rustc::ty::sty::ClosureSubsts::field_tys
  21: rustc_mir::transform::type_check::type_check
  22: <std::thread::local::LocalKey<T>>::with
  23: rustc::ty::context::GlobalCtxt::enter_local
  24: <rustc_mir::transform::type_check::TypeckMir as rustc_mir::transform::MirPass>::run_pass
  25: _ZN9rustc_mir9transform9mir_const28_$u7b$$u7b$closure$u7d$$u7d$17h41798532b9d3d81eE.llvm.1C47F73D
  26: rustc_mir::transform::mir_const
  27: rustc::ty::maps::<impl rustc::ty::maps::queries::mir_const<'tcx>>::compute_result
  28: _ZN5rustc9dep_graph5graph8DepGraph14with_task_impl17h358c5dbfda855a2cE.llvm.9B8CD3D8
  29: rustc_errors::Handler::track_diagnostics
  30: rustc::ty::maps::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::cycle_check
  31: rustc::ty::maps::<impl rustc::ty::maps::queries::mir_const<'tcx>>::force
  32: rustc::ty::maps::<impl rustc::ty::maps::queries::mir_const<'tcx>>::try_get
  33: rustc::ty::maps::TyCtxtAt::mir_const
  34: rustc::ty::maps::<impl rustc::ty::context::TyCtxt<'a, 'tcx, 'lcx>>::mir_const
  35: rustc_mir::transform::mir_validated
  36: rustc::ty::maps::<impl rustc::ty::maps::queries::mir_validated<'tcx>>::compute_result
  37: _ZN5rustc9dep_graph5graph8DepGraph14with_task_impl17h358c5dbfda855a2cE.llvm.9B8CD3D8
  38: rustc_errors::Handler::track_diagnostics
  39: rustc::ty::maps::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::cycle_check
  40: rustc::ty::maps::<impl rustc::ty::maps::queries::mir_validated<'tcx>>::force
  41: rustc::ty::maps::<impl rustc::ty::maps::queries::mir_validated<'tcx>>::try_get
  42: rustc::ty::maps::TyCtxtAt::mir_validated
  43: rustc::ty::maps::<impl rustc::ty::context::TyCtxt<'a, 'tcx, 'lcx>>::mir_validated
  44: _ZN14rustc_borrowck8borrowck8borrowck17hcedc9c7f4446392dE.llvm.D63B9554
  45: _ZN5rustc9dep_graph5graph8DepGraph14with_task_impl17h7859b748933c95dfE.llvm.9B8CD3D8
  46: rustc_errors::Handler::track_diagnostics
  47: rustc::ty::maps::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::cycle_check
  48: rustc::ty::maps::<impl rustc::ty::maps::queries::borrowck<'tcx>>::force
  49: rustc::ty::maps::<impl rustc::ty::maps::queries::borrowck<'tcx>>::try_get
  50: rustc::ty::maps::TyCtxtAt::borrowck
  51: rustc::ty::maps::<impl rustc::ty::context::TyCtxt<'a, 'tcx, 'lcx>>::borrowck
  52: rustc_borrowck::borrowck::check_crate
  53: <std::thread::local::LocalKey<T>>::with
  54: <std::thread::local::LocalKey<T>>::with
  55: rustc::ty::context::TyCtxt::create_and_enter
  56: rustc_driver::driver::compile_input
  57: rustc_driver::run_compiler

error: Could not compile `taggu`.

To learn more, run the command again with --verbose.

Output of rustc --version --verbose:

rustc 1.23.0-nightly (827cb0d61 2017-11-26)
binary: rustc
commit-hash: 827cb0d61e22eb6d5c9c5e8e8d05b07108a9968b
commit-date: 2017-11-26
host: x86_64-unknown-linux-gnu
release: 1.23.0-nightly
LLVM version: 4.0

[linclelinkpart5]

Also, just checked, this still occurs after updating to rustc 1.24.0-nightly (f9b0897 2017-12-02).