unused;

--- a/src/Pure/Tools/build_job.scala	Wed Mar 01 15:43:38 2023 +0100
+++ b/src/Pure/Tools/build_job.scala	Wed Mar 01 15:45:58 2023 +0100
@@ -88,9 +88,6 @@
     val old_time: Time,
     val old_command_timings_blob: Bytes
   ) {
-    def is_empty: Boolean =
-      old_time.is_zero && old_command_timings_blob.is_empty
-
     override def toString: String = name
   }