That's a standard error clause. In the case PyImport_ImportModule threw a Python exception, you need to Py_DECREF any C local variables which are new references(not borrowed references) and return -1.

From the later call PyModule_AddObject, it's clear this code has come from the PyInit_ module initialisation function. This code is running on import of the C extension to initialise the "FruitEnum" module attribute. https://docs.python.org/3/c-api/extension-modules.html#c.PyI...