puppetlabs/cfacter — pull request #229 by peterhuene (2014-11-21 18:14:40+00:00)
Title: (CFACT-145) Implement Ruby API looking hooks for client applications like Puppet.

These commits add the following methods to the Ruby API:

Facter.on_message
Facter.trace
Facter.trace?
Facter.debugging
Facter.debugging?

Additionally, the `--trace` option has been replaced with the `--log-level` option that now supports setting any log level (none, trace, debug, info, warning, error, or fatal).
The `--trace` option is now supported as "print stack traces for custom fact exceptions", which is the meaning of the `--trace` option under Ruby.