Conan:如何在conanfile.py的build步骤中访问或生成package id hash？

class MyPackage(conans.ConanFile):
    # ...

    def build(self):
        package_id = self.info.package_id()
        self.output.info("Package id hash: {}".format(package_id))

    # ...

class MyPackage(conans.ConanFile):
    # ...

    def package_id(self):
        # Generate package id hash based on build options
        my_hash = hashlib.md5()
        my_hash.update(self.options.option1.encode())
        my_hash.update(self.options.option2.encode())
        self.info.package_id = my_hash.hexdigest()

    # ...