error[E0585]: found a documentation comment that doesn't document anything
  --> $DIR/issue-48636.rs:7:5
   |
LL |     x: u8
   |          - help: missing comma here: `,`
LL |     /// The ID of the parent core
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: doc comments must come before what they document, maybe a comment was intended with `//`?

error: aborting due to previous error

For more information about this error, try `rustc --explain E0585`.