error: unexpected end of macro invocation
  --> $DIR/crate-type-macro-not-crate.rs:8:16
   |
LL | macro_rules! foo {
   | ---------------- when calling this macro
...
LL | #[crate_type = foo!()]
   |                ^^^^^^ missing tokens in macro arguments
   |
note: while trying to match meta-variable `$x:expr`
  --> $DIR/crate-type-macro-not-crate.rs:5:6
   |
LL |     ($x:expr) => {"rlib"}
   |      ^^^^^^^

error: aborting due to 1 previous error