Hi, As part of my work on PR #4899 (categorical splits for tree-based learners), I want to add a pointer member to the Node struct in sklearn/tree/_tree.pxd. But when I do this, it causes some of the unit tests to fail in the 32-bit Appveyor (Windows) CI. (Actually, it usually causes them to hang indefinitely.) I'm testing this with the latest commit on master. The patch I'm applying is listed in full below; it's tiny. If you like, I can make a new PR to demonstrate the behavior. Does anyone know why this would happen, and only on 32-bit windows? Thanks, Jeff ``` diff --git a/sklearn/tree/_tree.pxd b/sklearn/tree/_tree.pxd index dbf0545..b80e7bb 100644 --- a/sklearn/tree/_tree.pxd +++ b/sklearn/tree/_tree.pxd @@ -32,6 +32,7 @@ cdef struct Node: DOUBLE_t impurity # Impurity of the node (i.e., the value of the criterion) SIZE_t n_node_samples # Number of samples at the node DOUBLE_t weighted_n_node_samples # Weighted number of samples at the node + UINT32_t *foo cdef class Tree: diff --git a/sklearn/tree/_tree.pyx b/sklearn/tree/_tree.pyx index 4e8160f..a2f8117 100644 --- a/sklearn/tree/_tree.pyx +++ b/sklearn/tree/_tree.pyx @@ -68,9 +68,9 @@ cdef SIZE_t INITIAL_STACK_SIZE = 10 # Repeat struct definition for numpy NODE_DTYPE = np.dtype({ 'names': ['left_child', 'right_child', 'feature', 'threshold', 'impurity', - 'n_node_samples', 'weighted_n_node_samples'], + 'n_node_samples', 'weighted_n_node_samples', 'foo'], 'formats': [np.intp, np.intp, np.intp, np.float64, np.float64, np.intp, - np.float64], + np.float64, np.intp], 'offsets': [ <Py_ssize_t> &(<Node*> NULL).left_child, <Py_ssize_t> &(<Node*> NULL).right_child, @@ -78,7 +78,8 @@ NODE_DTYPE = np.dtype({ <Py_ssize_t> &(<Node*> NULL).threshold, <Py_ssize_t> &(<Node*> NULL).impurity, <Py_ssize_t> &(<Node*> NULL).n_node_samples, - <Py_ssize_t> &(<Node*> NULL).weighted_n_node_samples + <Py_ssize_t> &(<Node*> NULL).weighted_n_node_samples, + <Py_ssize_t> &(<Node*> NULL).foo ] }) ```