-FILES=`find $SRC -type f -mtime +1 -ctime +1 | head -n $COUNT`
-log "copying files from $SRC to $DST$SRC at `date`"
-tar cf - $FILES | tar xvf - -C $DST > /dev/null || fail "copying $SRC" 11
+FILES=`find $RUNTESTS_SRC -type f -mtime +1 | head -n $COUNT`
+[ -z "$FILES" ] && fail "No unchanged files - is $RUNTESTS_SRC a new dir?"
+
+log "copying files from $RUNTESTS_SRC to $DST$RUNTESTS_SRC at `date`"
+tar cf - $FILES | tar xvf - -C $DST > /dev/null || fail "copying $RUNTESTS_SRC" 11