error: malformed `crate_type` attribute input
  --> $DIR/crate-type-empty.rs:2:1
   |
LL | #![crate_type]
   | ^^^^^^^^^^^^^^
   |
   = note: for more information, visit <https://doc.rust-lang.org/reference/linkage.html>
help: the following are the possible correct uses
   |
LL | #![crate_type = "bin"]
   |               +++++++
LL | #![crate_type = "cdylib"]
   |               ++++++++++
LL | #![crate_type = "dylib"]
   |               +++++++++
LL | #![crate_type = "lib"]
   |               +++++++
   = and 4 other candidates

error: aborting due to 1 previous error