ubuntu_qrt_apparmor fails on ADT bionic/linux i386

Testing failed on:
    i386: https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_77e2ada1e7a84929a74ba3b87153c0ac/autopkgtest-bionic/bionic/i386/l/linux/20200326_224620_0dd01@/log.gz

Kernel version: bionic/linux 4.15.0-94.95

The ubuntu_qrt_apparmor.test-apparmor.py fails intermittently on bionic/linux i386 ADT tests. It has failed some releases in the past and I'm seeing the failure in the current release as well. I have not seen this failure on other architectures.

These are the last messages on the test log:
20:12:39 ERROR| [stderr] Test mediation of file based SOCK_STREAM connect ... ok
20:12:39 ERROR| [stderr] test_libapparmor_testsuite (__main__.ApparmorTestsuites)
20:14:18 DEBUG| [stdout] unconfined_user can access confined_user's file
20:14:18 DEBUG| [stdout] unconfined_user can access default_user's file
20:14:18 DEBUG| [stdout] unconfined_user can access unconfined_group's file
20:14:18 DEBUG| [stdout]
20:15:42 ERROR| [stderr] Run libapparmor testsuite ... (Applying patch 0001-mount-regression-test-convert-mount-test-to-use-MS_N.patch) (Applying patch 0001-usr-merge-fixups.patch) ok
20:15:42 ERROR| [stderr] test_libapparmor_testsuite3 (__main__.ApparmorTestsuites)
20:15:52 DEBUG| [stdout] preparing apparmor_2.12-4ubuntu5.1.dsc... done
20:15:52 DEBUG| [stdout]
20:17:10 ERROR| [stderr] Run libapparmor testsuite (with python3) ... (Applying patch 0001-mount-regression-test-convert-mount-test-to-use-MS_N.patch) (Applying patch 0001-usr-merge-fixups.patch) ok
20:17:10 ERROR| [stderr] test_old_trusty_parser_testsuite (__main__.ApparmorTestsuites)
20:17:10 DEBUG| [stdout] preparing apparmor_2.12-4ubuntu5.1.dsc... done
20:17:10 ERROR| [stderr] Run parser regression tests from 14.04's apparmor_2.8.95~2430-0ubuntu5.3 ... (skipped: This test is only for 14.04 systems with the apparmor 2.10.95 SRU or newer installed) ok
20:17:10 ERROR| [stderr] test_old_trusty_regression_testsuite (__main__.ApparmorTestsuites)
20:17:10 ERROR| [stderr] Run kernel regression tests from 14.04's apparmor_2.8.95~2430-0ubuntu5.3 ... (skipped: This test is only for 14.04 systems with the apparmor 2.10.95 SRU or newer installed) ok
20:17:10 ERROR| [stderr] test_parser_testsuite (__main__.ApparmorTestsuites)
20:17:19 DEBUG| [stdout]
20:52:35 ERROR| [stderr] Run parser regression tests ... (Applying patch 0001-mount-regression-test-convert-mount-test-to-use-MS_N.patch) (Applying patch 0001-usr-merge-fixups.patch) ok
20:52:35 ERROR| [stderr] test_regression_testsuite (__main__.ApparmorTestsuites)
20:52:42 DEBUG| [stdout] preparing apparmor_2.12-4ubuntu5.1.dsc... done
20:52:42 DEBUG| [stdout]
21:01:56 INFO | ERROR ubuntu_qrt_apparmor.test-apparmor.py ubuntu_qrt_apparmor.test-apparmor.py timestamp=1585256516 localtime=Mar 26 21:01:56 Test subprocess failed rc=9