E4084

The label is supplied twice when calling a function with labelled parameters.

Erroneous Example

pub fn f(a~ : Int) -> Unit {
  println("Hello, \{a}")
}

fn main {
  f(a=0, a=1) // Error: The label a~ is supplied twice.
}

Suggestion

As there is only one labelled parameter in the function call, you can simply provide a single value.

fn main {
  f(a=0)
}

When there are multiple labelled parameters in the function call, and you made a typo to make this error, then you can change the name of the label supplied to the correct one.

fn main {
  f(a=0, b=1)
}