error: expected one of `,` or `>`, found `;`
  --> $DIR/nested-missing-closing-angle-bracket.rs:2:46
   |
LL |   let v : Vec::<Vec<(u32,_,_)> = vec![vec![]];
   |         - while parsing the type for `v`     ^ expected one of `,` or `>`

error: aborting due to 1 previous error