HGPoller Error 2

2017-06-23 11:55:41-0700 [-] initializing www plugin 'console_view'
2017-06-23 11:55:41-0700 [-] initializing www plugin 'waterfall_view'
2017-06-23 11:55:41-0700 [-] BuildbotSite starting on 8011
2017-06-23 11:55:41-0700 [-] Starting factory <buildbot.www.service.BuildbotSite object at 0x7f9358821e48>
2017-06-23 11:55:41-0700 [-] adding 1 new workers, removing 0
2017-06-23 11:55:41-0700 [-] PBServerFactory starting on 9990
2017-06-23 11:55:41-0700 [-] Starting factory <twisted.spread.pb.PBServerFactory object at 0x7f93588282e8>
2017-06-23 11:55:41-0700 [-] BuildMaster is running
2017-06-23 11:55:41-0700 [-] buildbotNetUsageData: sending {'db': 'sqlite', 'versions': {'Buildbot': '0.9.8', 'Twisted': '17.5.0', 'Python': '3.5.2'}, 'www_plugins': ['console_view', 'waterfall_view'], 'mq': 'simple', 'platform': {'version': '#1 SMP Debian 3.16.7-ckt25-2+deb8u3', 'processor': '', 'machine': 'x86_64', 'system': 'Linux', 'python_implementation': 'CPython', 'platform': 'Linux-3.16.0-4-amd64-x86_64-with-debian-8.5', 'distro': 'debian:8'}, 'installid': '776248e31daa4dddd65569ef5e7013d801814ca0', 'plugins': {'buildbot/steps/source/mercurial/Mercurial': 1, 'buildbot/config/BuilderConfig': 1, 'buildbot/schedulers/forcesched/ForceScheduler': 1, 'buildbot/steps/shell/ShellCommand': 1, 'buildbot/schedulers/basic/SingleBranchScheduler': 1, 'buildbot/worker/base/Worker': 1, 'buildbot/changes/hgpoller/HgPoller': 1}}
2017-06-23 11:55:41-0700 [-] buildbotNetUsageData: buildbot.net said: ok
2017-06-23 11:56:40-0700 [-] hgpoller: polling hg repo at ssh://hg@hg.foo.com/sandbox/litterbox
2017-06-23 11:56:41-0700 [-] hgpoller: processing 1 changes: [[b'201', b'eefa9bb8899d402ab4793ea60b99bf867625e63d']] in '/home/bobthebuilder/p3/tmp/bb-master/master/poll-workdir'
2017-06-23 11:56:41-0700 [-] added change with revision b'eefa9bb8899d402ab4793ea60b99bf867625e63d' to database
2017-06-23 11:56:41-0700 [-] Got fatal Exception on DB
        Traceback (most recent call last):
          File "/home/bobthebuilder/p3/tmp/bb-master/sandbox/lib/python3.5/site-packages/twisted/python/threadpool.py", line 266, in <lambda>
            inContext.theWork = lambda: context.call(ctx, func, *args, **kw)
          File "/home/bobthebuilder/p3/tmp/bb-master/sandbox/lib/python3.5/site-packages/twisted/python/context.py", line 122, in callWithContext
            return self.currentContext().callWithContext(ctx, func, *args, **kw)
          File "/home/bobthebuilder/p3/tmp/bb-master/sandbox/lib/python3.5/site-packages/twisted/python/context.py", line 85, in callWithContext
            return func(*args,**kw)
          File "/home/bobthebuilder/p3/tmp/bb-master/sandbox/lib/python3.5/site-packages/buildbot/db/pool.py", line 209, in __thd
            log.err(e, 'Got fatal Exception on DB')
        --- <exception caught here> ---
          File "/home/bobthebuilder/p3/tmp/bb-master/sandbox/lib/python3.5/site-packages/buildbot/db/pool.py", line 183, in __thd
            rv = callable(arg, *args, **kwargs)
          File "/home/bobthebuilder/p3/tmp/bb-master/sandbox/lib/python3.5/site-packages/buildbot/db/state.py", line 124, in thd
            return self.thdSetState(conn, objectid, name, value)
          File "/home/bobthebuilder/p3/tmp/bb-master/sandbox/lib/python3.5/site-packages/buildbot/db/state.py", line 133, in thdSetState
            raise TypeError("Error encoding JSON for %r" % (value,))
        builtins.TypeError: Error encoding JSON for b'201'

2017-06-23 11:56:41-0700 [-] hgpoller: repo poll failed
2017-06-23 11:56:41-0700 [-] Unhandled Error
        Traceback (most recent call last):
          File "/home/bobthebuilder/p3/tmp/bb-master/sandbox/lib/python3.5/site-packages/twisted/internet/defer.py", line 500, in errback
            self._startRunCallbacks(fail)
          File "/home/bobthebuilder/p3/tmp/bb-master/sandbox/lib/python3.5/site-packages/twisted/internet/defer.py", line 567, in _startRunCallbacks
            self._runCallbacks()
          File "/home/bobthebuilder/p3/tmp/bb-master/sandbox/lib/python3.5/site-packages/twisted/internet/defer.py", line 653, in _runCallbacks
            current.result = callback(current.result, *args, **kw)
          File "/home/bobthebuilder/p3/tmp/bb-master/sandbox/lib/python3.5/site-packages/twisted/internet/defer.py", line 1442, in gotResult
            _inlineCallbacks(r, g, deferred)
        --- <exception caught here> ---
          File "/home/bobthebuilder/p3/tmp/bb-master/sandbox/lib/python3.5/site-packages/twisted/internet/defer.py", line 1384, in _inlineCallbacks
            result = result.throwExceptionIntoGenerator(g)
          File "/home/bobthebuilder/p3/tmp/bb-master/sandbox/lib/python3.5/site-packages/twisted/python/failure.py", line 393, in throwExceptionIntoGenerator
            return g.throw(self.type, self.value, self.tb)
          File "/home/bobthebuilder/p3/tmp/bb-master/sandbox/lib/python3.5/site-packages/buildbot/changes/hgpoller.py", line 303, in _processChanges
            yield self._setCurrentRev(rev, oid=oid)
          File "/home/bobthebuilder/p3/tmp/bb-master/sandbox/lib/python3.5/site-packages/twisted/python/threadpool.py", line 250, in inContext
            result = inContext.theWork()
          File "/home/bobthebuilder/p3/tmp/bb-master/sandbox/lib/python3.5/site-packages/twisted/python/threadpool.py", line 266, in <lambda>
            inContext.theWork = lambda: context.call(ctx, func, *args, **kw)
          File "/home/bobthebuilder/p3/tmp/bb-master/sandbox/lib/python3.5/site-packages/twisted/python/context.py", line 122, in callWithContext
            return self.currentContext().callWithContext(ctx, func, *args, **kw)
          File "/home/bobthebuilder/p3/tmp/bb-master/sandbox/lib/python3.5/site-packages/twisted/python/context.py", line 85, in callWithContext
            return func(*args,**kw)
          File "/home/bobthebuilder/p3/tmp/bb-master/sandbox/lib/python3.5/site-packages/buildbot/db/pool.py", line 183, in __thd
            rv = callable(arg, *args, **kwargs)
          File "/home/bobthebuilder/p3/tmp/bb-master/sandbox/lib/python3.5/site-packages/buildbot/db/state.py", line 124, in thd
            return self.thdSetState(conn, objectid, name, value)
          File "/home/bobthebuilder/p3/tmp/bb-master/sandbox/lib/python3.5/site-packages/buildbot/db/state.py", line 133, in thdSetState
            raise TypeError("Error encoding JSON for %r" % (value,))
        builtins.TypeError: Error encoding JSON for b'201'

2017-06-23 11:56:41-0700 [-] added buildset 1 to database