serialized_options TypeError

Problem

I built and installed Caffe2. Running a simple Caffe2 Python call, gave this error:

$ python -c "from caffe2.python import core"
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/usr/local/lib/python2.7/dist-packages/caffe2/python/__init__.py", line 2, in <module>
    from caffe2.proto import caffe2_pb2
  File "/usr/local/lib/python2.7/dist-packages/caffe2/proto/__init__.py", line 11, in <module>
    from caffe2.proto import caffe2_pb2, metanet_pb2, torch_pb2
  File "/usr/local/lib/python2.7/dist-packages/caffe2/proto/caffe2_pb2.py", line 23, in <module>
    \x44\x65viceTypeProto\x12\r\n\tPROTO_CPU\x10\x00\x12\x0e\n\nPROTO_CUDA\x10\x01\x12\x10\n\x0cPROTO_MKLDNN\x10\x02\x12\x10\n\x0cPROTO_OPENGL\x10\x03\x12\x10\n\x0cPROTO_OPENCL\x10\x04\x12\x0f\n\x0bPROTO_IDEEP\x10\x05\x12\r\n\
tPROTO_HIP\x10\x06\x12\x0e\n\nPROTO_FPGA\x10\x07\x12\x0f\n\x0bPROTO_MSNPU\x10\x08\x12\r\n\tPROTO_XLA\x10\t\x12\'\n#PROTO_COMPILE_TIME_MAX_DEVICE_TYPES\x10\n\x12\x19\n\x13PROTO_ONLY_FOR_TEST\x10\xa5\xa3\x01')
TypeError: __new__() got an unexpected keyword argument 'serialized_options'

Solution

This is caused by an older version of Protobuf. Updating that solved the problem:

$ pip install -U protobuf

Tried with: Raspbian 9