v4 refactor for GP module

conda-envs/windows-environment-test-py38.yml

@@ -12,7 +12,8 @@ dependencies:
 - fastprogress>=0.2.0
 - h5py>=2.7
 - libpython
-- mkl-service
+- mkl==2020.4
+- mkl-service==2.3.0
 - m2w64-toolchain
 - numpy>=1.15.0
 - pandas

pymc/gp/cov.py

@@ -64,7 +64,7 @@ def __init__(self, input_dim, active_dims=None):
         if active_dims is None:
             self.active_dims = np.arange(input_dim)
         else:
-            self.active_dims = np.asarray(active_dims, np.int)
+            self.active_dims = np.asarray(active_dims, int)
 
     def __call__(self, X, Xs=None, diag=False):
         r"""
@@ -152,7 +152,9 @@ def __array_wrap__(self, result):
         elif isinstance(result[0][0], Prod):
             return result[0][0].factor_list[0] * A
         else:
-            raise RuntimeError
+            raise TypeError(
+                f"Unknown Covariance combination type {result[0][0]}.  Known types are `Add` or `Prod`."
+            )
 
 
 class Combination(Covariance):