[stable/train] neutron and networking-ovn jobs failing with ImportError: No module named yaml

[Miguel Lavalle]

The following jobs in networking-ovn stable/train are failing:

networking-ovn-tempest-dsvm-ovs-release
networking-ovn-tempest-dsvm-ovs-release-python2
networking-ovn-rally-task
networking-ovn-octavia-v2-dsvm-scenario

The failure is:

Traceback (most recent call last):
  File "<stdin>", line 107, in <module>
  File "<stdin>", line 99, in _ansiballz_main
  File "<stdin>", line 48, in invoke_module
  File "/usr/lib/python2.7/runpy.py", line 188, in run_module
    fname, loader, pkg_name)
  File "/usr/lib/python2.7/runpy.py", line 82, in _run_module_code
    mod_name, mod_fname, mod_loader, pkg_name)
  File "/usr/lib/python2.7/runpy.py", line 72, in _run_code
    exec code in run_globals
  File "/tmp/ansible_test_matrix_payload_2DcL4X/ansible_test_matrix_payload.zip/ansible/modules/test_matrix.py", line 21, in <module>
ImportError: No module named yaml

The failure seems to be in https://github.com/openstack/devstack-gate/blob/2c891c51d564a23053f11023434a4fa4e55ddfd5/roles/test-matrix/tasks/main.yaml

[Bernard Cafarelli (bcafarel)]

I am adding neutron to the bug, we have similar failures on stable/train backports:
https://review.opendev.org/c/openstack/neutron/+/860326
https://review.opendev.org/c/openstack/neutron/+/860327

Sample neutron-functional failure: https://zuul.opendev.org/t/openstack/build/0b1421ab65834fb992674522073bb5b7

[Miguel Lavalle (minsel)]

Proposed fix: https://review.opendev.org/c/openstack/devstack-gate/+/860961

[Miguel Lavalle (minsel)]

Proposed fix in devstack-gate solved the problem