This may be an actual bugzilla bug, not positive. Reproducer:

$ cat test.py
import bugzilla

BZURL = 'https://bugzilla.redhat.com/xmlrpc.cgi'

bzapi = bugzilla.RHBugzilla3(url=BZURL)

bug = bzapi.query({"bug_id" : "579899"})[0]

print bug.get_flag_type("needinfo")

$ python test.py 
Traceback (most recent call last):
  File "test.py", line 9, in <module>
    print bug.get_flag_type("needinfo")
  File "/usr/lib/python2.7/site-packages/bugzilla/base.py", line 1364, in get_flag_type
    for t in self.flag_types:
  File "/usr/lib/python2.7/site-packages/bugzilla/base.py", line 1216, in __getattr__
    raise AttributeError, "field %s not in bugzilla.bugfields" % name
AttributeError: field flag_types not in bugzilla.bugfields



bugfields here is:

['alias', 'assigned_to', 'attach_data.thedata', 'attachments.description', 'attachments.filename', 'attachments.isobsolete', 'attachments.ispatch', 'attachments.isprivate', 'attachments.isurl', 'attachments.mimetype', 'attachments.submitter', 'attachstatusdefs.name', 'blocked', 'bug_file_loc', 'bug_group', 'bug_id', 'bug_severity', 'bug_status', 'build_id', 'cc', 'cclist_accessible', 'class', 'classification', 'clone_of', 'commenter', 'comments', 'component', 'conditional_nak', 'content', 'creation_ts', 'crm', 'cust_facing', 'days_elapsed', 'deadline', 'delta_ts', 'dependson', 'devel_whiteboard', 'documentation_action', 'environment', 'estimated_time', 'everconfirmed', 'ext_bz_bug_map.ext_bz_bug_id', 'external_bugzilla.description', 'external_bugzilla.url', 'extra_component', 'extra_version', 'fixed_in', 'flagtypes.name', 'groups', 'internal_whiteboard', 'issuetracker', 'keywords', 'last_closed', 'longdesc', 'longdescs.isprivate', 'mount_type', 'op_sys', 'owner_idle_time', 'partner', 'password', 'percentage_complete', 'priority', 'product', 'qa_contact', 'qa_whiteboard', 'qe_conditional_nak', 'regression_status', 'release_notes', 'remaining_time', 'rep_platform', 'reporter', 'reporter_accessible', 'requestees.login_name', 'resolution', 'see_also', 'setters.login_name', 'short_desc', 'status_whiteboard', 'story_points', 'target_milestone', 'target_release', 'targetrelease', 'type', 'vcs_commits', 'verified', 'verified_branch', 'version', 'view', 'votes', 'work_time']


The following diff against upstream makes it work:

$ git diff
diff --git a/bugzilla/base.py b/bugzilla/base.py
index f4707e0..14e3d2e 100644
--- a/bugzilla/base.py
+++ b/bugzilla/base.py
@@ -1361,7 +1361,9 @@ class _Bug(object):
         #XXX: make a "flag index" dictionary instead of walking the
         #     flag_types list every time?
 
-        for t in self.flag_types:
+        self.refresh()
+        flag_types = self.__dict__["flag_types"]
+        for t in flag_types:
             if t['name'] == name:
                 return t
 
So is the problem just that the bugzilla api getBugFields isn't returning flag_types ? I assume this worked at some point...