Currently it uses Craft CLI, but that is because legacy reasons (it was integrated to the rest of Charmcraft code before), and it relies in its functionality but as it's run as a script, it's not used (e.g., showing progress). Furthermore, the added timestamp dirties the logs. So instead of using the Emitter, we should set up a logging infrastructure that will just show the message to the terminal (no timestamp, no log level, etc), and transform the 14 `emit.trace` calls in `logger.debug` and the 5 `emit.progress` calls in `logger.info`. By default the logger level should be INFO, but if the script is run with a `--trace` flag it should change to DEBUG. When preparing the script to run, in the `charm` plugin, we should use that flag in some cases: - if Charmcraft is run in quiet or normal mode, `charm_builder.py` should be called without the flag (nothing will be seen, its INFO lines will be saved into the logs) - if Charmcraft is run in verbose mode, `charm_builder.py` should be called without the flag (its INFO lines will be seen and saved into the logs) - if Charmcraft is run in trace mode, `charm_builder.py` should be called **with** the flag (its INFO and DEBUG lines will be seen and saved into the logs) We also should stop raising CraftError as it just means a crash.