vlib/v/checker/tests/generic_closure_fn_decl_err_a.vv:5:2: error: generic closure fn must specify type parameter, e.g. fn [foo] [T]()
    3 | 
    4 | pub fn (mut app App) register[T](service T) {
    5 |     fn [service] () {
      |     ~~~~~~~~~~~~~~~~~
    6 |         println(service)
    7 |     }()