Recent nightly-no-x11 build failed (cmake failure is handled on mailing list), and something went wrong in cooker.py. The resulting log is is almost 400MB of python traceback that looks like this:

b'\x80\x03cbb.cooker\nCookerExit\nq\x00)\x81q\x01}q\x02X\x03\x00\x00\x00pidq\x03K\x00sb.' is not JSON serializable Traceback (most recent call last):
  File "/home/pokybuild/yocto-autobuilder/yocto-worker/nightly-no-x11/build/bitbake/lib/bb/cooker.py", line 330, in write_event
    f.write("%s\n" % json.dumps({"class":event.__module__ + "." + event.__class__.__name__, "vars":json.dumps(pickle.dumps(event)) }))
  File "/usr/lib/python3.4/json/__init__.py", line 230, in dumps
    return _default_encoder.encode(obj)
  File "/usr/lib/python3.4/json/encoder.py", line 192, in encode
    chunks = self.iterencode(o, _one_shot=True)
  File "/usr/lib/python3.4/json/encoder.py", line 250, in iterencode
    return _iterencode(o, 0)
  File "/usr/lib/python3.4/json/encoder.py", line 173, in default
    raise TypeError(repr(o) + " is not JSON serializable")
TypeError: b'\x80\x03cbb.cooker\nCookerExit\nq\x00)\x81q\x01}q\x02X\x03\x00\x00\x00pidq\x03K\x00sb.' is not JSON serializable