workaround for python visibility

cpp/src/plasma/plasma.h

@@ -51,6 +51,12 @@
     }                                                                       \
   } while (0);
 
+/// Fix visibility of the Python C extension entry point
+#ifdef PyMODINIT_FUNC
+#undef PyMODINIT_FUNC
+#endif
+#define PyMODINIT_FUNC extern "C" __attribute__((visibility ("default"))) PyObject*
+
 /// Allocation granularity used in plasma for object allocation.
 #define BLOCK_SIZE 64