error[E0116]: cannot define inherent `impl` for a type outside of the crate where the type is defined
  --> $DIR/E0116.rs:1:1
   |
LL | impl Vec<u8> {}
   | ^^^^^^^^^^^^^^^ impl for type defined outside of crate.
   |
   = note: define and implement a trait or new type instead

error: aborting due to previous error

For more information about this error, try `rustc --explain E0116`.