On following manual installation, while running -
$ python populate.py
It raises an error - ValueError("No config value 'endpoints' found.")

This is probably because of missing config file, or invalid value set in filenames = [os.environ["FEDMSG_CONFIG"]]

On setting the environment variable as- FEDMSG_CONFIG=hubs/default_config.py
The server runs successfully, but the website shows only the header, without any widgets/ options to add widgets.

The complete error is as follows:
(hubs) [nupur@localhost fedora-hubs]$ python populate.py
Traceback (most recent call last):
File "populate.py", line 8, in
import hubs.models
File "/home/nupur/Desktop/fedora-hubs/hubs/models.py", line 50, in
import hubs.widgets
File "/home/nupur/Desktop/fedora-hubs/hubs/widgets/init.py", line 80, in
from .registry import WidgetRegistry
File "/home/nupur/Desktop/fedora-hubs/hubs/widgets/registry.py", line 5, in
from hubs.widgets.base import Widget
File "/home/nupur/Desktop/fedora-hubs/hubs/widgets/base.py", line 10, in
from .caching import CachedFunction
File "/home/nupur/Desktop/fedora-hubs/hubs/widgets/caching.py", line 9, in
from hubs.utils.cache import cache
File "/home/nupur/Desktop/fedora-hubs/hubs/utils/cache.py", line 30, in
cache = _get_cache()
File "/home/nupur/Desktop/fedora-hubs/hubs/utils/cache.py", line 25, in _get_cache
fedmsg_config = get_fedmsg_config()
File "/home/nupur/Desktop/fedora-hubs/hubs/utils/init.py", line 18, in get_fedmsg_config
fedmsg_config = fedmsg.config.load_config(filenames=filenames)
File "/home/nupur/.virtualenvs/hubs/lib/python2.7/site-packages/fedmsg/config.py", line 159, in load_config
raise ValueError("No config value 'endpoints' found.")
ValueError: No config value 'endpoints' found.