Fail to build diorite

Loaded package `/usr/share/vala-0.38/vapi/glib-2.0.vapi'
Loaded package `/usr/share/vala-0.38/vapi/gobject-2.0.vapi'
Loaded package `/usr/share/vala-0.38/vapi/posix.vapi'
Loaded package `/usr/share/vala-0.38/vapi/gio-2.0.vapi'
Loaded package `/usr/share/vala-0.38/vapi/gio-unix-2.0.vapi'
Loaded package `/usr/share/vala-0.38/vapi/gtk+-3.0.vapi'
Loaded package `/usr/share/vala-0.38/vapi/atk.vapi'
Loaded package `/usr/share/vala-0.38/vapi/cairo.vapi'
Loaded package `/usr/share/vala-0.38/vapi/gdk-pixbuf-2.0.vapi'
Loaded package `/usr/share/vala-0.38/vapi/gdk-3.0.vapi'
Loaded package `/usr/share/vala-0.38/vapi/pango.vapi'
Loaded package `/usr/share/vala-0.38/vapi/pangocairo.vapi'
Loaded package `/usr/share/vala-0.38/vapi/x11.vapi'
Loaded package `/usr/share/vala-0.38/vapi/gdk-x11-3.0.vapi'
Loaded package `/home/exad/diorite/build/dioriteglib4.vapi'
Compilation failed: 2 error(s), 2 warning(s)

dioriteglib4.vapi:116.102-116.109: error: The name `Priority' does not exist in the context of `Drt.System.make_directory_with_parents_async'
		public static async void make_directory_with_parents_async (GLib.File directory, int io_priority = Priority.DEFAULT, GLib.Cancellable? cancellable = null) throws GLib.Error;
		                                                                                                   ^^^^^^^^

** (valac:5406): CRITICAL **: vala_data_type_compatible: assertion 'self != NULL' failed

** (valac:5406): CRITICAL **: vala_code_node_to_string: assertion 'self != NULL' failed
dioriteglib4.vapi:116.102-116.117: error: Cannot convert from `(null)' to `int'
		public static async void make_directory_with_parents_async (GLib.File directory, int io_priority = Priority.DEFAULT, GLib.Cancellable? cancellable = null) throws GLib.Error;
		                                                                                                   ^^^^^^^^^^^^^^^^
/home/exad/diorite/src/gtk/SlideInRevealer.vala:59.3-59.37: warning: Gtk.Widget.override_background_color has been deprecated since 3.16
/home/exad/diorite/src/gtk/RichTextBuffer.vala:643.35-643.43: warning: Gtk.Stock has been deprecated since 3.10

Build failed
 -> task in 'dioritedb4' failed with exit status 1:
	{task 139834931089984: valac BindExpression.vala,Connection.vala,Database.vala,ObjectCursor.vala,ObjectQuery.vala,ObjectSpec.vala,OrmManager.vala,Query.vala,Queryable.vala,Result.vala,main.vala -> dioritedb4.h,dioritedb4.vapi,Drtdb-1.0.gir,dioritedb4.deps,BindExpression.c,Connection.c,Database.c,ObjectCursor.c,ObjectQuery.c,ObjectSpec.c,OrmManager.c,Query.c,Queryable.c,Result.c,main.c}
''
 -> task in 'dioritegtk4' failed with exit status 1:
	{task 139834931017264: valac Action.vala,Actions.vala,Application.vala,ApplicationWindow.vala,Css.vala,DesktopShell.vala,Dialogs.vala,Entry.vala,EntryMultiCompletion.vala,Forms.vala,GtkThemeSelector.vala,HeaderBarTitle.vala,Icons.vala,InfoBarStack.vala,Labels.vala,Misc.vala,PopoverButton.vala,RichTextBuffer.vala,RichTextView.vala,SlideInRevealer.vala,StackMenuButton.vala,X11.vala -> dioritegtk4.h,dioritegtk4.vapi,Drtgtk-1.0.gir,dioritegtk4.deps,Action.c,Actions.c,Application.c,ApplicationWindow.c,Css.c,DesktopShell.c,Dialogs.c,Entry.c,EntryMultiCompletion.c,Forms.c,GtkThemeSelector.c,HeaderBarTitle.c,Icons.c,InfoBarStack.c,Labels.c,Misc.c,PopoverButton.c,RichTextBuffer.c,RichTextView.c,SlideInRevealer.c,StackMenuButton.c,X11.c}