Error in importing tvm.relay

hi, I’m trying to play around with relay, but I get the following error:

junhao@junhao-desktop:~/incubator-tvm$ python3
Python 3.6.8 (default, Oct  7 2019, 12:59:55)
[GCC 8.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import tvm.relay
Traceback (most recent call last):

  File "<stdin>", line 1, in <module>

  File "/usr/local/lib/python3.6/dist-packages/tvm-0.6.dev0-py3.6-linux-aarch64.egg/tvm/relay/__init__.py", line 27, in <module>
    from . import expr_functor

  File "/usr/local/lib/python3.6/dist-packages/tvm-0.6.dev0-py3.6-linux-aarch64.egg/tvm/relay/expr_functor.py", line 24, in <module>
    from .op import Op

  File "/usr/local/lib/python3.6/dist-packages/tvm-0.6.dev0-py3.6-linux-aarch64.egg/tvm/relay/op/__init__.py", line 20, in <module>
    from .op import get, register, register_schedule, register_compute, register_gradient, \

  File "/usr/local/lib/python3.6/dist-packages/tvm-0.6.dev0-py3.6-linux-aarch64.egg/tvm/relay/op/op.py", line 19, in <module>
    import topi

  File "/usr/local/lib/python3.6/dist-packages/topi-0.6.dev0-py3.6.egg/topi/__init__.py", line 26, in <module>
    from . import nn

  File "/usr/local/lib/python3.6/dist-packages/topi-0.6.dev0-py3.6.egg/topi/nn/__init__.py", line 6, in <module>
    from .deformable_conv2d import *

  File "/usr/local/lib/python3.6/dist-packages/topi-0.6.dev0-py3.6.egg/topi/nn/deformable_conv2d.py", line 23, in <module>
    from ..cpp.image import bilinear_sample_nchw

ImportError: cannot import name 'bilinear_sample_nchw'

Maybe try: cannot import name 'bilinear_sample_nchw'