Error while processing the build request with "buildbot sendchange" command

Question

I am using this command to start a build:

buildbot sendchange --master=domain:9989 --who=tom --auth=username:'xxxxxxx' --branch=testing --project="apps/project-1" --category="apps"  --comment="push to build" application.yml tahani/tahani.model.py

The command is starting the build with the error:

exceptions.TypeError: unbound method _defaultCollapseRequestFn() must be called with Builder instance as first argument (got BuildMaster instance instead)

Detailed traceback:

    Traceback (most recent call last):
      File "/usr/local/lib/python2.7/dist-packages/twisted/internet/defer.py", line 501, in errback
        self._startRunCallbacks(fail)
      File "/usr/local/lib/python2.7/dist-packages/twisted/internet/defer.py", line 568, in _startRunCallbacks
        self._runCallbacks()
      File "/usr/local/lib/python2.7/dist-packages/twisted/internet/defer.py", line 654, in _runCallbacks
        current.result = callback(current.result, *args, **kw)
      File "/usr/local/lib/python2.7/dist-packages/twisted/internet/defer.py", line 1475, in gotResult
        _inlineCallbacks(r, g, status)
    --- <exception caught here> ---
      File "/usr/local/lib/python2.7/dist-packages/twisted/internet/defer.py", line 1416, in _inlineCallbacks
        result = result.throwExceptionIntoGenerator(g)
      File "/usr/local/lib/python2.7/dist-packages/twisted/python/failure.py", line 491, in throwExceptionIntoGenerator
        return g.throw(self.type, self.value, self.tb)
      File "/usr/local/lib/python2.7/dist-packages/buildbot/schedulers/basic.py", line 219, in gotChange
        yield BaseBasicScheduler.gotChange(self, change, important)
      File "/usr/local/lib/python2.7/dist-packages/twisted/internet/defer.py", line 1416, in _inlineCallbacks
        result = result.throwExceptionIntoGenerator(g)
      File "/usr/local/lib/python2.7/dist-packages/twisted/python/failure.py", line 491, in throwExceptionIntoGenerator
        return g.throw(self.type, self.value, self.tb)
      File "/usr/local/lib/python2.7/dist-packages/buildbot/schedulers/base.py", line 286, in addBuildsetForChanges
        properties=properties, **kw)
      File "/usr/local/lib/python2.7/dist-packages/twisted/internet/defer.py", line 1416, in _inlineCallbacks
        result = result.throwExceptionIntoGenerator(g)
      File "/usr/local/lib/python2.7/dist-packages/twisted/python/failure.py", line 491, in throwExceptionIntoGenerator
        return g.throw(self.type, self.value, self.tb)
      File "/usr/local/lib/python2.7/dist-packages/buildbot/schedulers/base.py", line 323, in addBuildsetForSourceStamps
        external_idstring=external_idstring, **kw)
      File "/usr/local/lib/python2.7/dist-packages/twisted/internet/defer.py", line 1416, in _inlineCallbacks
        result = result.throwExceptionIntoGenerator(g)
      File "/usr/local/lib/python2.7/dist-packages/twisted/python/failure.py", line 491, in throwExceptionIntoGenerator
        return g.throw(self.type, self.value, self.tb)
      File "/usr/local/lib/python2.7/dist-packages/buildbot/data/buildsets.py", line 147, in addBuildset
        yield BuildRequestCollapser(self.master, list(itervalues(brids))).collapse()
      File "/usr/local/lib/python2.7/dist-packages/twisted/internet/defer.py", line 1418, in _inlineCallbacks
        result = g.send(result)
      File "/usr/local/lib/python2.7/dist-packages/buildbot/process/buildrequest.py", line 82, in collapse
        canCollapse = yield collapseRequestsFn(self.master, bldr, br, unclaim_br)
    exceptions.TypeError: unbound method _defaultCollapseRequestFn() must be called with Builder instance as first argument (got BuildMaster instance instead)

builbot version:

Buildbot version: 0.9.0b9
Twisted version: 18.9.0