errors of "already stripped" when build busybox

I want to use busybox in SELinux and need to enable INDIVIDUAL feature.
CONFIG_BUILD_LIBBUSYBOX=y
CONFIG_FEATURE_INDIVIDUAL=y
CONFIG_FEATURE_SHARED_BUSYBOX=y
$ bitbake busybox
returns errors regarding "already stripped":

WARNING: busybox-1.24.1-r0 do_populate_sysroot: File
'/usr/lib/libbusybox.so.1.24.1' from busybox was already stripped, this
will prevent future debugging!
ERROR: busybox-1.24.1-r0 do_package: QA Issue: File '/sbin/ifup.busybox'
from busybox was already stripped, this will prevent future debugging!
[already-stripped]
ERROR: busybox-1.24.1-r0 do_package: QA Issue: File '/sbin/insmod.busybox'
from busybox was already stripped, this will prevent future debugging!
[already-stripped]
ERROR: busybox-1.24.1-r0 do_package: QA Issue: File '/sbin/swapoff.busybox'
from busybox was already stripped, this will prevent future debugging!
[already-stripped]
..................................................................................

Where should I modify it to get rid of "already stripped"?

Thanks.

---henry