error: extern items cannot be `const`
  --> $DIR/extern-const.rs:14:11
   |
LL |     const rust_dbg_static_mut: c_int;
   |           ^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, visit https://doc.rust-lang.org/std/keyword.extern.html
help: try using a static value
   |
LL -     const rust_dbg_static_mut: c_int;
LL +     static rust_dbg_static_mut: c_int;
   |

error: aborting due to 1 previous error