Instance not being installed

Hey, I have following code:

                    let mut instance = InstanceBuilder::default()
                        .name(data.get_name())
                        .version(data.get_version())
                        .instance_path("/tmp/cobble_core/test_instance".to_string())
                        .libraries_path("/tmp/cobble_core/libraries".to_string())
                        .assets_path("/tmp/cobble_core/assets".to_string())
                        .build()
                        .unwrap();

                    let (tx, rx) = InstallationUpdate::channel(500);
                    tokio::join! {
                        instance.full_installation(5, 5, true, tx),
                        process_updates(rx),
                    };

                    println!("{}", instance.installed);

But full_installation doesn't actually install it. I don't get process updates and it prints false for instance.installed. data.get_name() is at the Hallo and data.get_version() is 1.19.2 (also tried 1.8.9). Do you have any idea why that could be?