rrename build.py to build_extension due to issues on mac devices

build_extension.py

@@ -0,0 +1,62 @@
+import sys
+import numpy as np
+from setuptools import setup, Extension
+
+
+def ismac():
+    return sys.platform[:6] == "darwin"
+
+if ismac():
+    compile_flags = ["-O3"]
+    link_args = []
+else:
+    compile_flags = ["-fopenmp", "-O3"]
+    link_args = ["-lgomp"]
+
+extensions = [
+    Extension(
+        name="GPy.kern.src.stationary_cython",
+        sources=[
+            "GPy/kern/src/stationary_cython.pyx",
+            "GPy/kern/src/stationary_utils.c",
+        ],
+        include_dirs=[np.get_include(), "."],
+        extra_compile_args=compile_flags,
+        extra_link_args=link_args,
+    ),
+    Extension(
+        name="GPy.util.choleskies_cython",
+        sources=["GPy/util/choleskies_cython.pyx"],
+        include_dirs=[np.get_include(), "."],
+        extra_link_args=link_args,
+        extra_compile_args=compile_flags,
+    ),
+    Extension(
+        name="GPy.util.linalg_cython",
+        sources=["GPy/util/linalg_cython.pyx"],
+        include_dirs=[np.get_include(), "."],
+        extra_compile_args=compile_flags,
+        extra_link_args=link_args,
+    ),
+    Extension(
+        name="GPy.kern.src.coregionalize_cython",
+        sources=["GPy/kern/src/coregionalize_cython.pyx"],
+        include_dirs=[np.get_include(), "."],
+        extra_compile_args=compile_flags,
+        extra_link_args=link_args,
+    ),
+    Extension(
+        name="GPy.models.state_space_cython",
+        sources=["GPy/models/state_space_cython.pyx"],
+        include_dirs=[np.get_include(), "."],
+        extra_compile_args=compile_flags,
+        extra_link_args=link_args,
+    ),
+]
+
+def build(setup_kwargs):
+    """Needed for the poetry building interface."""
+    setup_kwargs.update({
+        'ext_modules': extensions,
+        # 'include_dirs': [np.get_include()],
+    })