diff -r ba4ed9a50be3 -r 167660a8f99e src/Pure/System/isabelle_system.scala
--- a/src/Pure/System/isabelle_system.scala	Mon May 30 10:15:27 2022 +0200
+++ b/src/Pure/System/isabelle_system.scala	Mon May 30 10:31:56 2022 +0200
@@ -424,6 +424,7 @@
     cwd: JFile = null,
     progress: Progress = new Progress,
     verbose: Boolean = false,
+    thorough: Boolean = false,
     dry_run: Boolean = false,
     clean: Boolean = false,
     filter: List[String] = Nil,
@@ -432,6 +433,7 @@
     val script =
       "rsync --protect-args --archive" +
         (if (verbose || dry_run) " --verbose" else "") +
+        (if (thorough) " --ignore-times" else "") +
         (if (dry_run) " --dry-run" else "") +
         (if (clean) " --delete-excluded" else "") +
         filter.map(s => " --filter=" + Bash.string(s)).mkString +