ENH: update error message in __Pyx_ImportType when basicsize doesn't

match.

Changes the error message to include the sizes of the two
structures. This aids in debugging the it allows us to check the sizes
to see which version we were built against versus the version we have at
runtime.

Cython/Utility/ImportExport.c

@@ -394,14 +394,14 @@ static PyTypeObject *__Pyx_ImportType(const char *module_name, const char *class
 #endif
     if (!strict && (size_t)basicsize > size) {
         PyOS_snprintf(warning, sizeof(warning),
-            "%s.%s size changed, may indicate binary incompatibility",
-            module_name, class_name);
+            "%s.%s size changed, may indicate binary incompatibility. Expected %zd, got %zd",
+            module_name, class_name, basicsize, size);
         if (PyErr_WarnEx(NULL, warning, 0) < 0) goto bad;
     }
     else if ((size_t)basicsize != size) {
         PyErr_Format(PyExc_ValueError,
-            "%.200s.%.200s has the wrong size, try recompiling",
-            module_name, class_name);
+            "%.200s.%.200s has the wrong size, try recompiling. Expected %zd, got %zd",
+            module_name, class_name, basicsize, size);
         goto bad;
     }
     return (PyTypeObject *)result;