Python-heatclient fails with 'Empty module name' when using relative path

[Harri Heikkilä]

You get error message as described in https://bugs.launchpad.net/horizon/+bug/1475279 horizon fails because heatclient cannot handle relative path (../..)

but when you change Line 8 in /usr/local/lib/python2.7/dist-packages/openstack_dashboard/wsgi/django.wsgi from:
sys.path.insert(0, os.path.join(os.path.dirname(os.path.realpath(__file__)), '../..')) to absolute path:
sys.path.insert(0, os.path.join(os.path.dirname(os.path.realpath(__file__)), '/usr/local/lib/python2.7/dist-packages'))

Then the error goes away.
Based on in bug 1475279 comment:
"Matthias Runge (mrunge) wrote on 2015-07-20:
then it's a heatclient issue (missing dependency)"
I could guess that this is heat client issue then. Or simply configuration issue, but hard to see where.

I can confirm that Error occurs also when installing horizon (stable/liberty) from sources:

Jan 29 12:27:55 controlplane01 '[horizon]'[27138]:
Jan 29 12:27:55 controlplane01 '[horizon]'[27138]: utils.import_modules_from_package("osprofiler._notifiers")
Jan 29 12:27:55 controlplane01 '[horizon]'[27138]: File "/usr/local/lib/python2.7/dist-packages/openstack_dashboard/wsgi/../../osprofiler/_utils.py", line 174, in import_modules_from_package
Jan 29 12:27:55 controlplane01 '[horizon]'[27138]:
Jan 29 12:27:55 controlplane01 '[horizon]'[27138]: __import__(module_name)
Jan 29 12:27:55 controlplane01 '[horizon]'[27138]: ValueError
Jan 29 12:27:55 controlplane01 '[horizon]'[27138]: :
Jan 29 12:27:55 controlplane01 '[horizon]'[27138]: Empty module name
Jan 29 12:27:55 controlplane01 '[horizon]'[27138]:
Jan 29 12:27:55 controlplane01 '[horizon]'[27138]: unable to load app 0 (mountpoint='') (callable not found or import error)