I can confirm the issue, it happens when running the testsuite without a virtualenv, i.e. with different Python module versions:

2012-12-12 17:07:38 ======================================================================
2012-12-12 17:07:38 ERROR: test_add_image_with_image_data_as_file_with_sendfile (glance.tests.unit.test_clients.TestClient)
2012-12-12 17:07:38 ----------------------------------------------------------------------
2012-12-12 17:07:38 Traceback (most recent call last):
2012-12-12 17:07:38   File "/var/lib/openstack-glance-test/glance/tests/utils.py", line 109, in _skipper
2012-12-12 17:07:38     func(*args, **kw)
2012-12-12 17:07:38   File "/var/lib/openstack-glance-test/glance/tests/unit/test_clients.py", line 1858, in test_add_image_with_image_data_as_file_with_sendfile
2012-12-12 17:07:38     self.add_image_with_image_data_as_file(sendfile=True)
2012-12-12 17:07:38   File "/var/lib/openstack-glance-test/glance/tests/unit/test_clients.py", line 1814, in add_image_with_image_data_as_file
2012-12-12 17:07:38     new_image = self.client.add_image(fixture, open(tmp_image_filepath))
2012-12-12 17:07:38   File "/var/lib/openstack-glance-test/glance/client.py", line 165, in add_image
2012-12-12 17:07:38     res = self.do_request("POST", "/images", body, headers)
2012-12-12 17:07:38   File "/var/lib/openstack-glance-test/glance/common/client.py", line 63, in wrapped
2012-12-12 17:07:38     return func(self, *args, **kwargs)
2012-12-12 17:07:38   File "/var/lib/openstack-glance-test/glance/common/client.py", line 444, in do_request
2012-12-12 17:07:38     headers=headers)
2012-12-12 17:07:38   File "/var/lib/openstack-glance-test/glance/common/client.py", line 80, in wrapped
2012-12-12 17:07:38     return func(self, method, url, body, headers)
2012-12-12 17:07:38   File "/var/lib/openstack-glance-test/glance/common/client.py", line 589, in _do_request
2012-12-12 17:07:38     raise exception.ClientConnectionError(e)
2012-12-12 17:07:38 ClientConnectionError: The client disconnected while sending the POST/PUT body (19 more bytes were expected)

While I haven't yet found out why, I discovered something strange:

% ./run_tests.sh -N -s --pdb glance.tests.unit.test_clients:TestClient.test_add_image_with_image_data_as_file_with_sendfile
/root/Projects/suse/openstack/glance/glance/tests/unit/test_clients.py:22: UserWarning: The 'glance.client' module is deprecated in favor of the 'glanceclient' module provided by python-glanceclient (see http://github.com/openstack/python-glanceclient).
  from glance import client

TestClient
    test_add_image_with_image_data_as_file_with_sendfile         > /root/Projects/suse/openstack/glance/glance/common/client.py(589)_do_request()
-> raise exception.ClientConnectionError(e)
(Pdb) l
584                 else:
585                     raise exception.UnexpectedStatus(status=status_code,
586                                                      body=res.read())
587     
588             except (socket.error, IOError), e:
589  ->             raise exception.ClientConnectionError(e)
590     
591         def _seekable(self, body):
592             # pipes are not seekable, avoids sendfile() failure on e.g.
593             #   cat /path/to/image | glance add ...
594             # or where add command is launched via popen
(Pdb) up
> /root/Projects/suse/openstack/glance/glance/common/client.py(80)wrapped()
-> return func(self, method, url, body, headers)
(Pdb) up
> /root/Projects/suse/openstack/glance/glance/common/client.py(444)do_request()
-> headers=headers)
(Pdb) p body.read()
'chunk00000remainderchunk00000remainder'
(Pdb) p body.tell()
38


Although the actual file content is only "chunk00000remainder" (len 19).