error[E0282]: type annotations needed for `(Vec<_>,)`
  --> $DIR/cannot_infer_local_or_vec_in_tuples.rs:2:9
   |
LL |     let (x, ) = (vec![], );
   |         ^^^^^   ---------- type must be known at this point
   |
help: consider giving this pattern a type, where the placeholders `_` are specified
   |
LL |     let (x, ): (Vec<_>,) = (vec![], );
   |              +++++++++++

error: aborting due to previous error

For more information about this error, try `rustc --explain E0282`.