R Error message 'argument fdef is missing with no default`

Question

The following code fails with the error message shown above.

#' Generic setter for XiFit class
#'
#' @param knots Knots object to which weights are applied
#' @param weights Given weights
#'
#' @return Object of XiFit class
#' @export
#' @rdname XiFit_setter
setGeneric("setXiFit",
           function(knots, weights){
               standardGeneric("setXiFit")
           }
)

I do not understand what is missing. I have no object with the name fdef.

This code is in a package I wrote two years ago. I am pretty sure that the package used to work!

Can anyone explain what is going on?

Answer 1

fdefis an argument to the function standardGeneric. An argument is an input to a function. According to the function description fdef should be the function definition.