r2d2 not supported with AsyncPgConnection about diesel_async HOT 2 CLOSED

$ cargo build --features r2d2
   Compiling diesel-async v0.4.1 (/Users/dport/github/diesel_async)
error[E0728]: `await` is only allowed inside `async` functions and blocks
  --> src/pooled_connection/r2d2.rs:67:14
   |
65 | /     fn connect(&self) -> Result<Self::Connection, Self::Error> {
66 | |         (self.manager_config.custom_setup)(&self.connection_url)
67 | |             .await
   | |              ^^^^^ only allowed inside `async` functions and blocks
68 | |             .map_err(PoolError::ConnectionError)
69 | |     }
   | |_____- this is not `async`

error[E0728]: `await` is only allowed inside `async` functions and blocks
  --> src/pooled_connection/r2d2.rs:73:14
   |
71 | /     fn is_valid(&self, conn: &mut Self::Connection) -> Result<(), Self::Error> {
72 | |         conn.ping(&self.manager_config.recycling_method)
73 | |             .await
   | |              ^^^^^ only allowed inside `async` functions and blocks
74 | |             .map_err(PoolError::QueryError)
75 | |     }
   | |_____- this is not `async`

For more information about this error, try `rustc --explain E0728`.
error: could not compile `diesel-async` (lib) due to 2 previous errors