Yes, it was a typo but now that I have changes that I got this:
SamplingError: Initial evaluation of model at starting point failed!
Starting values:
{‘slope’: array(0.00049181), ‘intercept’: array(0.80299521)}
Initial evaluation results:
slope -inf
intercept -inf
y -23.72
Name: Log-probability of test_point, dtype: float64
I will try the debug that you suggested