Steps to reproduce: run Honcho on Heroku, for example by putting "web: honcho -f ProcfileHoncho start" into your Procfile and "honcho==0.4.0" into your requirements.txt.
2013-04-01T17:31:29+00:00 heroku[web.1]: State changed from crashed to starting
2013-04-01T17:31:48+00:00 heroku[web.1]: Starting process with command `honcho -f ProcfileHoncho start`
2013-04-01T17:31:49+00:00 app[web.1]: load_entry_point('honcho==0.4.0', 'console_scripts', 'honcho')()
2013-04-01T17:31:49+00:00 app[web.1]: File "/app/.heroku/python/lib/python2.7/site-packages/pkg_resources.py", line 337, in load_entry_point
2013-04-01T17:31:49+00:00 app[web.1]: return get_distribution(dist).load_entry_point(group, name)
2013-04-01T17:31:49+00:00 app[web.1]: File "/app/.heroku/python/lib/python2.7/site-packages/pkg_resources.py", line 2279, in load_entry_point
2013-04-01T17:31:49+00:00 app[web.1]: return ep.load()
2013-04-01T17:31:49+00:00 app[web.1]: Traceback (most recent call last):
2013-04-01T17:31:49+00:00 app[web.1]: File "/app/.heroku/python/bin/honcho", line 9, in <module>
2013-04-01T17:31:49+00:00 app[web.1]: File "/app/.heroku/python/lib/python2.7/site-packages/pkg_resources.py", line 1989, in load
2013-04-01T17:31:49+00:00 app[web.1]: entry = __import__(self.module_name, globals(),globals(), ['__name__'])
2013-04-01T17:31:49+00:00 app[web.1]: File "/app/.heroku/python/lib/python2.7/site-packages/honcho/command.py", line 66, in <module>
2013-04-01T17:31:49+00:00 app[web.1]: class Honcho(object):
2013-04-01T17:31:49+00:00 app[web.1]: default=os.environ['USERNAME' if compat.ON_WINDOWS else 'USER'],
2013-04-01T17:31:49+00:00 app[web.1]: File "/app/.heroku/python/lib/python2.7/site-packages/honcho/command.py", line 205, in Honcho
2013-04-01T17:31:49+00:00 app[web.1]: File "/app/.heroku/python/lib/python2.7/UserDict.py", line 23, in __getitem__
2013-04-01T17:31:49+00:00 app[web.1]: raise KeyError(key)
2013-04-01T17:31:49+00:00 app[web.1]: KeyError: 'USER'
2013-04-01T17:31:50+00:00 heroku[web.1]: Process exited with status 1
2013-04-01T17:31:50+00:00 heroku[web.1]: State changed from starting to crashed
heroku config:set USER=heroku