error: repetition matches empty token tree
  --> $DIR/issue-5067.rs:9:8
   |
LL |     ( $()* ) => {};
   |        ^^

error: repetition matches empty token tree
  --> $DIR/issue-5067.rs:11:8
   |
LL |     ( $()+ ) => {};
   |        ^^

error: repetition matches empty token tree
  --> $DIR/issue-5067.rs:13:8
   |
LL |     ( $()? ) => {};
   |        ^^

error: repetition matches empty token tree
  --> $DIR/issue-5067.rs:18:9
   |
LL |     ( [$()*] ) => {};
   |         ^^

error: repetition matches empty token tree
  --> $DIR/issue-5067.rs:20:9
   |
LL |     ( [$()+] ) => {};
   |         ^^

error: repetition matches empty token tree
  --> $DIR/issue-5067.rs:22:9
   |
LL |     ( [$()?] ) => {};
   |         ^^

error: repetition matches empty token tree
  --> $DIR/issue-5067.rs:27:8
   |
LL |     ( $($()* $(),* $(a)* $(a),* )* ) => {};
   |        ^^^^^^^^^^^^^^^^^^^^^^^^^^

error: repetition matches empty token tree
  --> $DIR/issue-5067.rs:29:8
   |
LL |     ( $($()* $(),* $(a)* $(a),* )+ ) => {};
   |        ^^^^^^^^^^^^^^^^^^^^^^^^^^

error: repetition matches empty token tree
  --> $DIR/issue-5067.rs:31:8
   |
LL |     ( $($()* $(),* $(a)* $(a),* )? ) => {};
   |        ^^^^^^^^^^^^^^^^^^^^^^^^^^

error: repetition matches empty token tree
  --> $DIR/issue-5067.rs:33:8
   |
LL |     ( $($()? $(),* $(a)? $(a),* )* ) => {};
   |        ^^^^^^^^^^^^^^^^^^^^^^^^^^

error: repetition matches empty token tree
  --> $DIR/issue-5067.rs:35:8
   |
LL |     ( $($()? $(),* $(a)? $(a),* )+ ) => {};
   |        ^^^^^^^^^^^^^^^^^^^^^^^^^^

error: repetition matches empty token tree
  --> $DIR/issue-5067.rs:37:8
   |
LL |     ( $($()? $(),* $(a)? $(a),* )? ) => {};
   |        ^^^^^^^^^^^^^^^^^^^^^^^^^^

error: repetition matches empty token tree
  --> $DIR/issue-5067.rs:47:12
   |
LL |     ( $(a $()+)* ) => {};
   |            ^^

error: repetition matches empty token tree
  --> $DIR/issue-5067.rs:49:12
   |
LL |     ( $(a $()*)+ ) => {};
   |            ^^

error: repetition matches empty token tree
  --> $DIR/issue-5067.rs:51:12
   |
LL |     ( $(a $()+)? ) => {};
   |            ^^

error: repetition matches empty token tree
  --> $DIR/issue-5067.rs:53:12
   |
LL |     ( $(a $()?)+ ) => {};
   |            ^^

error: repetition matches empty token tree
  --> $DIR/issue-5067.rs:60:18
   |
LL |     (a $e1:expr $($(, a $e2:expr)*)*) => ([$e1 $($(, $e2)*)*]);
   |                  ^^^^^^^^^^^^^^^^^^

error: repetition matches empty token tree
  --> $DIR/issue-5067.rs:71:8
   |
LL |     ( $()* ) => {};
   |        ^^

error: aborting due to 18 previous errors