error: couldn't read the file
  --> $DIR/extented-attribute-macro-error.rs:3:10
   |
LL | #![doc = include_str!("../not_existing_file.md")]
   |          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: attribute value must be a literal
  --> $DIR/extented-attribute-macro-error.rs:3:10
   |
LL | #![doc = include_str!("../not_existing_file.md")]
   |          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: aborting due to 2 previous errors