The code (number) comes directly from Puppet. Previously the installation would fail, too, saying nothing else.
0: The run succeeded with no changes or failures; the system was already in the desired state.
1: The run failed, or wasn't attempted due to another run already in progress.
2: The run succeeded, and some resources were changed.
4: The run succeeded, and some resources failed.
6: The run succeeded, and included both changes and failures.
So the only ones useful for our purposes are 0 (But that should never happen unless you run the installer and then immediately run it again) and 2.