Roxygenize fails with... is.call(call) is not TRUE

Question

Every time I try to roxygenize a package I get this error:

Error: is.call(call) is not TRUE

The results of a traceback():

11: stop(sprintf(ngettext(length(r), "%s is not TRUE", "%s are not all TRUE"), 
        ch), call. = FALSE, domain = NA)
10: stopifnot(is.call(call))
9: standardise_call(call, env)
8: object_from_call(call, env, preref)
7: (function (call, ref, comment_ref) 
   {
       preref <- parse.preref(as.character(comment_ref))
       if (is.null(preref)) 
           return()
       preref$object <- object_from_call(call, env, preref)
       preref$srcref <- list(filename = file, lloc = as.vector(ref))
       add_defaults(preref)
   })(dots[[1L]][[1L]], dots[[2L]][[1L]], dots[[3L]][[1L]])
6: mapply(FUN = f, ..., SIMPLIFY = FALSE)
5: Map(extract, parsed, refs, comment_refs)
4: FUN(c("/home/path/to/package/file1.r", 
   "/home/path/to/package/file2.r", 
   .... # list of files truncated 
   "/home/path/to/package/doc.file.r")[[25L]], 
       ...)
3: lapply(r_files(base_path), parse_file, env = env)
2: parse_package(base_path, load_code)
1: roxygenize("~/Current/r/path/to/package/")

Has anyone experienced this problem before? I'm not even sure how to debug it further.

Answer 1

This error occurs if, instead of the typical NULL value that one puts at the end of the documentation for the package, one uses NA. Simply updating to NULL will remove the error.