[shotgun] Diagnostic snapshot creation fails: AttributeError: 'NoneType' object has no attribute 'strip'

[Artem Panchenko]

Diagnostic snapshot generation fails with the following error:

[root@nailgun ~]# shotgun -c /tmp/dump_config
2015-12-23 17:51:32 DEBUG 1122 (manager) Initializing snapshot manager
2015-12-23 17:51:32 DEBUG 1122 (manager) Making snapshot
2015-12-23 17:51:32 DEBUG 1122 (utils) Trying to execute command: rm -rf /var/www/nailgun/dump
2015-12-23 17:51:32 DEBUG 1122 (manager) Dumping: {u'username': u'nailgun', u'dbhost': u'10.109.45.2', 'host': {}, u'password': u'pqXqiq0g', u'type': u'postgres', u'dbname': u'nailgun'}
2015-12-23 17:51:32 DEBUG 1122 (driver) Initializing driver Postgres: host={}
2015-12-23 17:51:32 DEBUG 1122 (driver) Running local command: /usr/bin/mktemp
2015-12-23 17:51:32 DEBUG 1122 (utils) Trying to execute command: /usr/bin/mktemp
Traceback (most recent call last):
  File "/usr/bin/shotgun", line 9, in <module>
    load_entry_point('shotgun==8.0.0', 'console_scripts', 'shotgun')()
  File "/usr/lib/python2.7/site-packages/shotgun/cli.py", line 71, in main
    make_snapshot(parse_args())
  File "/usr/lib/python2.7/site-packages/shotgun/cli.py", line 65, in make_snapshot
    snapshot_path = manager.snapshot()
  File "/usr/lib/python2.7/site-packages/shotgun/manager.py", line 37, in snapshot
    self.snapshot_single(obj_data)
  File "/usr/lib/python2.7/site-packages/shotgun/manager.py", line 52, in snapshot_single
    driver.snapshot()
  File "/usr/lib/python2.7/site-packages/shotgun/driver.py", line 226, in snapshot
    temp = self.command("/usr/bin/mktemp").output.strip()
AttributeError: 'NoneType' object has no attribute 'strip'

This bug is a regression after https://github.com/openstack/shotgun/commit/d5dc87599c0a403ae032f48ef3cf8751e9f06836

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/261087

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/8.0
Review: https://review.openstack.org/261088

[OpenStack Infra (hudson-openstack)]

Change abandoned by Artem Panchenko (<email address hidden>) on branch: master
Review: https://review.openstack.org/261087
Reason: https://review.openstack.org/#/c/260970/

[OpenStack Infra (hudson-openstack)]

Change abandoned by Artem Panchenko (<email address hidden>) on branch: stable/8.0
Review: https://review.openstack.org/261088
Reason: https://review.openstack.org/#/c/260970/