You have a few options:

- Dagger supports opentelemetry natively: it emits traces, metrics and logs that you can send to your favorite observability tool, or to our commercial product Dagger Cloud (which has a free tier) which lets you drill down into the trace. See https://docs.dagger.io/features/visualization

- The Dagger CLI also renders the otel traces, and you can browse them as well. Press escape, then navigate with up, down, enter, escape. Same drill-down functionality but straight from the CLI

- You can call dagger with the --interactive flag. If you do, in case of an error you will get an interactive shell to inspect the state at time of failure.

- You can also call the `Container.terminal()` function from your code, to force an interactive terminal to appear for the user at that stage. Sort of like a "debug printf" but with an interactive terminal