I'm running into an odd error when defining a lambda function in go. Here's the code snippet:

lambdaFunction, err := lambda.NewFunction(ctx, "slacker", &lambda.FunctionArgs{
			Runtime: "python3.6",
			Code: asset.NewAssetArchive(map[string]interface{}{
				".": asset.NewFileArchive("./function.zip"),
			}),
			Timeout: 300,
			Handler: "function.lambda_handler",
			Role:    lambdaRole.Name(),
		})