Description of problem:
Package rust-owning_ref fails to build from source in Fedora rawhide.

Version-Release number of selected component (if applicable):
0.3.3-2.fc28

Steps to Reproduce:
koji build --scratch f28 rust-owning_ref-0.3.3-2.fc28.src.rpm

Additional info:
This package is tracked by Koschei. See:
http://apps.fedoraproject.org/koschei/package/rust-owning_ref

---

     Running `/usr/bin/rustc --crate-name owning_ref src/lib.rs --emit=dep-info,link -C opt-level=3 --test -C metadata=0bb96e66022b507c -C extra-filename=-0bb96e66022b507c --out-dir /builddir/build/BUILD/owning_ref-0.3.3/target/release/deps -L dependency=/builddir/build/BUILD/owning_ref-0.3.3/target/release/deps --extern stable_deref_trait=/builddir/build/BUILD/owning_ref-0.3.3/target/release/deps/libstable_deref_trait-9d2100c35620454f.rlib -Copt-level=3 -Cdebuginfo=2 -Clink-arg=-Wl,-z,relro,-z,now`
error[E0597]: `a[..]` does not live long enough
    --> src/lib.rs:1266:68
     |
1266 |             let o: BoxRef<&[i32; 2], i32> = o.map(|a: &&[i32; 2]| &a[0]);
     |                                                                    ^^^^- borrowed value only lives until here
     |                                                                    |
     |                                                                    does not live long enough
     |
note: borrowed value must be valid for the anonymous lifetime #2 defined on the body at 1266:51...
    --> src/lib.rs:1266:51
     |
1266 |             let o: BoxRef<&[i32; 2], i32> = o.map(|a: &&[i32; 2]| &a[0]);
     |                                                   ^^^^^^^^^^^^^^^^^^^^^
error[E0597]: `a[..]` does not live long enough
    --> src/lib.rs:1697:91
     |
1697 |             let o: BoxRefMut<&mut [i32; 2], i32> = o.map_mut(|a: &mut &mut [i32; 2]| &mut a[0]);
     |                                                                                           ^^^^ does not live long enough
...
1701 |         }
     |         - borrowed value only lives until here
     |
note: borrowed value must be valid for the anonymous lifetime #2 defined on the body at 1697:62...
    --> src/lib.rs:1697:62
     |
1697 |             let o: BoxRefMut<&mut [i32; 2], i32> = o.map_mut(|a: &mut &mut [i32; 2]| &mut a[0]);
     |                                                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: aborting due to 2 previous errors
error: Could not compile `owning_ref`.