AttributeError: 'TestFitALine' object has no attribute 'truth_val'

[LuLu2kANG]

the branch is v0.8.3
python3.8.10
client build success
app build success
server build success
pip3 install success

but when run the cmd: python3 -m paddle_serving_server.serve check

error occur:

../../usr/local/lib/python3.8/dist-packages/paddle_serving_server/env_check/test_fit_a_line.py
AttributeError: 'TestFitALine' object has no attribute 'truth_val'

[github-actions]

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