Control test:

ubuntu@game-cicada:~/src/ovn$ uname -a
Linux game-cicada 5.15.0-41-generic #44-Ubuntu SMP Wed Jun 22 14:20:53 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux
ubuntu@game-cicada:~/src/ovn$ git -C ./ovs status
HEAD detached at 6f24c2bc7
nothing to commit, working tree clean
ubuntu@game-cicada:~/src/ovn$ git status
On branch main
Your branch is up to date with 'origin/main'.

nothing to commit, working tree clean
ubuntu@game-cicada:~/src/ovn$ wget -qO - https://bugs.launchpad.net/ubuntu/+source/ovn/+bug/1967856/+attachment/5579267/+files/test-synthesis.patch|patch -p1
patching file tests/system-ovn.at
Hunk #1 succeeded at 6699 (offset 15 lines).
Hunk #2 succeeded at 6724 (offset 15 lines).
Hunk #3 succeeded at 6750 (offset 15 lines).
ubuntu@game-cicada:~/src/ovn$ make check-kernel SUDO=sudo TESTSUITEFLAGS=169
make  all-am
make[1]: Entering directory '/home/ubuntu/src/ovn'
/bin/bash '/home/ubuntu/src/ovn/build-aux/missing' autom4te --language=autotest -I '.' -o tests/system-kmod-testsuite.tmp tests/system-kmod-testsuite.at
mv tests/system-kmod-testsuite.tmp tests/system-kmod-testsuite
/bin/bash '/home/ubuntu/src/ovn/build-aux/missing' autom4te --language=autotest -I '.' -o tests/system-userspace-testsuite.tmp tests/system-userspace-testsuite.at
mv tests/system-userspace-testsuite.tmp tests/system-userspace-testsuite
make[1]: Leaving directory '/home/ubuntu/src/ovn'
set /bin/bash './tests/system-kmod-testsuite' -C tests  AUTOTEST_PATH='/home/ubuntu/src/ovn/ovs/utilities:/home/ubuntu/src/ovn/ovs/vswitchd:/home/ubuntu/src/ovn/ovs/ovsdb:/home/ubuntu/src/ovn/ovs/vtep:tests:::controller-vtep:northd:utilities:controller:ic'; \
sudo "$@" 169 -j1 || (test X'' = Xyes && sudo "$@" --recheck)
## ------------------------ ##
## ovn 22.06.90 test suite. ##
## ------------------------ ##
169: DNAT LR hairpin IPv4 -- ovn-northd -- parallelization=yes -- ovn_monitor_all=yes FAILED (system-ovn.at:6661)

## ------------- ##
## Test results. ##
## ------------- ##

ERROR: 1 test was run,
1 failed unexpectedly.

Verification:

ubuntu@game-cicada:~/src/ovn$ uname -a
Linux game-cicada 5.15.0-43-generic #46-Ubuntu SMP Tue Jul 12 10:30:17 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux
ubuntu@game-cicada:~/src/ovn$ git -C ./ovs status
HEAD detached at 6f24c2bc7
nothing to commit, working tree clean
ubuntu@game-cicada:~/src/ovn$ git status
On branch main
Your branch is up to date with 'origin/main'.

Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git restore <file>..." to discard changes in working directory)
	modified:   tests/system-ovn.at

Untracked files:
  (use "git add <file>..." to include in what will be committed)
	tests/system-ovn.at.orig

no changes added to commit (use "git add" and/or "git commit -a")
ubuntu@game-cicada:~/src/ovn$ make check-kernel SUDO=sudo TESTSUITEFLAGS=169
make  all-am
make[1]: Entering directory '/home/ubuntu/src/ovn'
make[1]: Leaving directory '/home/ubuntu/src/ovn'
set /bin/bash './tests/system-kmod-testsuite' -C tests  AUTOTEST_PATH='/home/ubuntu/src/ovn/ovs/utilities:/home/ubuntu/src/ovn/ovs/vswitchd:/home/ubuntu/src/ovn/ovs/ovsdb:/home/ubuntu/src/ovn/ovs/vtep:tests:::controller-vtep:northd:utilities:controller:ic'; \
sudo "$@" 169 -j1 || (test X'' = Xyes && sudo "$@" --recheck)
## ------------------------ ##
## ovn 22.06.90 test suite. ##
## ------------------------ ##
169: DNAT LR hairpin IPv4 -- ovn-northd -- parallelization=yes -- ovn_monitor_all=yes ok

## ------------- ##
## Test results. ##
## ------------- ##

1 test was successful.