Comment 1 for bug 2000359

Add "set -x" to posix_mq.sh script will give us some clue about this failure:

+ do_tests 'unconfined root' pass pass pass pass
+ prefix='unconfined root'
+ expect_send=pass
+ expect_recv=pass
+ expect_open=pass
+ all_args=("$@")
+ rest_args=("${all_args[@]:5}")
+ do_test 'unconfined root' pass /tmp/testlibxbcgpuwp/source/kinetic/apparmor-3.0.7/tests/regression/apparmor/posix_mq_snd pass -c /tmp/testlibxbcgpuwp/source/kinetic/apparmor-3.0.7/tests/regression/apparmor/posix_mq_snd -k /queuename
+ local 'desc=POSIX MQUEUE (unconfined root)'
+ shift
+ runchecktest 'POSIX MQUEUE (unconfined root)' pass /tmp/testlibxbcgpuwp/source/kinetic/apparmor-3.0.7/tests/regression/apparmor/posix_mq_snd pass -c /tmp/testlibxbcgpuwp/source/kinetic/apparmor-3.0.7/tests/regression/apparmor/posix_mq_snd -k /queuename
+ '[' -z '' ']'
+ trap error_handler ERR
+ runtestfg 'POSIX MQUEUE (unconfined root)' pass /tmp/testlibxbcgpuwp/source/kinetic/apparmor-3.0.7/tests/regression/apparmor/posix_mq_snd pass -c /tmp/testlibxbcgpuwp/source/kinetic/apparmor-3.0.7/tests/regression/apparmor/posix_mq_snd -k /queuename
+ _testdesc='POSIX MQUEUE (unconfined root)'
+ '[' p == x ']'
+ _pfmode=pass
+ _known=
+ shift 2
+ genrunscript /tmp/testlibxbcgpuwp/source/kinetic/apparmor-3.0.7/tests/regression/apparmor/posix_mq_snd pass -c /tmp/testlibxbcgpuwp/source/kinetic/apparmor-3.0.7/tests/regression/apparmor/posix_mq_snd -k /queuename
+ local runfile
+ '[' false = true ']'
+ _pid=383471
+ wait 383471
+ /tmp/testlibxbcgpuwp/source/kinetic/apparmor-3.0.7/tests/regression/apparmor/posix_mq_rcv /tmp/testlibxbcgpuwp/source/kinetic/apparmor-3.0.7/tests/regression/apparmor/posix_mq_snd pass -c /tmp/testlibxbcgpuwp/source/kinetic/apparmor-3.0.7/tests/regression/apparmor/posix_mq_snd -k /queuename
+ test_rc=1
+ '[' 1 -gt 128 ']'
+ checktestfg
+ local ret expectedsig killedsig
++ cat /tmp/sdtest.383410-8658-VS6Rmq/output.posix_mq_rcv
+ ret='Unrecognized option

Usage: /tmp/testlibxbcgpuwp/source/kinetic/apparmor-3.0.7/tests/regression/apparmor/posix_mq_rcv [options]
Options are:
-n get notified if there'\''s an item in the queue
          available options are: mq_notify, select, poll and epoll
-k message queue name (default is /testmq)
-c path of the client binary
-u run test as specified UID
-t timeout in seconds'

It's the posix_mq_rcv binary in command:
/tmp/testlibxbcgpuwp/source/kinetic/apparmor-3.0.7/tests/regression/apparmor/posix_mq_rcv /tmp/testlibxbcgpuwp/source/kinetic/apparmor-3.0.7/tests/regression/apparmor/posix_mq_snd pass -c /tmp/testlibxbcgpuwp/source/kinetic/apparmor-3.0.7/tests/regression/apparmor/posix_mq_snd -k /queuename

Complaining "Unrecognized option" here.
It's unclear why this issue is only affecting Kinetic arm64 for the moment.