How should a Dist::Zilla plugin give feedback to the user?

Question

I have a couple of Dist::Zilla plugins that I wrote when I was very new to Moose and to Dist::Zilla both, and I'm currently trying to update them to make them a bit more robust, and less error-prone.

One thing I would like to do is to give the user feedback if I detect that they have given me contradictory or impossible instructions. Things like:

[ MyPlugin ]
include = all
exclude = all

Dist::Zilla does appear to have an (undocumented) internal logging system which I originally hooked into when I wrote my plugins, but which no longer seems to work (probably due to internal changes). So, how should I give the user feedback these days?

Answer 1

(Meant to put this in the comment but hit length limit).

Caveat: I've only written a couple of small dzil plugins myself, and am not very familiar with its internals.

dzil uses Log::Dispatchouli, which is also written by rjbs. Log::Dispatchouli is used by several other projects (including projects started by people other than rjbs), so it's not exactly an internal dzil logging system.

From what I understand, Log::Dispatchouli only has two logging levels, normal and debug. Debug logs are not normally seen in output; you have to enable debugging first. Normal (and debug) logs can be muted if you enable muting.

To enable debugging in dzil, add a -v command-line switch. This does not seem to be documented in 'dzil help' nor 'dzil help COMMAND'. But rjbs blogged about it.

Now to produce logs inside the dzil plugins, you just call $self->log(...) or $self->log_debug(...). The second one will be seen only if user passes -v option.