E4019

The label is declared twice in this function.

Erroneous Example

pub fn f(g~ : Int, g~ : String) -> Unit {
  ignore(g)
}

The above example declares the label g twice in the function f, which is not allowed and gives the following error on line 1:

The label g~ is declared twice in this function, first in <FILE>.mbt:1:6

Suggestion

Rename one of the labels to avoid the conflict:

pub fn f(g~ : Int, h~ : String) -> Int {
  ignore(h)
  g
}