@@ -2293,14 +2293,24 @@
        ;; 'new2old
        )
       (set! *didsomething* #t)))
 
 (if (args:get-arg "-sync-to-megatest.db")
-    (let ((res (db:multi-db-sync 
-                (db:setup #f)
-                'new2old)))
-      (print "Synced " res " records to megatest.db")
+    (let* ((dbstruct (db:setup #f))
+	   (tmpdbpth (cdr (dbr:dbstruct-tmpdb dbstruct)))
+	   (lockfile (conc tmpdbpth ".lock"))
+	   (locked   (common:simple-file-lock lockfile)) 
+	   (res      (if locked
+			 (db:multi-db-sync 
+			  dbstruct
+			  'new2old)
+			 #f)))
+      (if res
+	  (begin
+	    (common:simple-file-release-lock lockfile)
+	    (print "Synced " res " records to megatest.db"))
+	  (print "Skipping sync, there is a sync in progress."))
       (set! *didsomething* #t)))
 
 (if (args:get-arg "-sync-to")
     (let ((toppath (launch:setup)))
       (tasks:sync-to-postgres *configdat* (args:get-arg "-sync-to"))