roxygen2 requires _PACKAGE now

R/package.R

@@ -12,7 +12,6 @@
 #' new features like caching and finer control of graphics. It is not limited to
 #' LaTeX and is ready to be customized to process other file formats. See the
 #' package website in the references for more information and examples.
-#' @docType package
 #' @name knitr-package
 #' @aliases knitr
 #' @import graphics grDevices stats utils
@@ -28,7 +27,7 @@
 #' @importFrom xfun attr file_ext is_windows loadable parse_only
 #'   sans_ext try_silent with_ext read_utf8 write_utf8 file_string
 #'   is_R_CMD_check is_abs_path
-NULL
+'_PACKAGE'
 
 .knitEnv = new.env()