error[E0019]: static contains unimplemented expression type
  --> $DIR/assign-to-static-within-other-static-2.rs:16:5
   |
LL |     *FOO.0.get() = 5;
   |     ^^^^^^^^^^^^^^^^
   |
   = help: add `#![feature(const_mut_refs)]` to the crate attributes to enable

error: aborting due to previous error

For more information about this error, try `rustc --explain E0019`.