@property
    def custom_dir(self):
        envname = "{}_DIR".format(self.name.upper())
        d = environ.get(envname)
        if not d:
            return
        if not exists(d):
            raise ValueError("Invalid path passed into {}".format(envname))
        return d
Check if there is a variable name to specify a custom version /
dataset/ETHPy150Open kivy/kivy-ios/toolchain.py/Recipe.custom_dir