error: unexpected `(` after qualified path
  --> $DIR/vec-macro-in-pattern.rs:5:14
   |
LL |         Some(vec![_x]) => (),
   |              ^^^^^^^^
   |              |
   |              unexpected `(` after qualified path
   |              in this macro invocation
   |              help: use a slice pattern here instead: `[_x]`
   |
   = help: for more information, see https://doc.rust-lang.org/edition-guide/rust-2018/slice-patterns.html
   = note: this warning originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)

error: aborting due to previous error