So here is the SHA I'm working with `fe71d7bcb49b47236ba720a0115af4472fcad0b1`

In order to create the error I'm doing this:
```
$ FACTER_kernel=foo bundle exec facter        
Error: undefined method `interfaces' for nil:NilClass
```
And if you run with --trace you can see where things are blowing up:
```
$ FACTER_kernel=foo bundle exec facter --trace
/Users/haileekenney/Projects/facter/lib/facter/util/ip.rb:92:in `interfaces': undefined method `interfaces' for nil:NilClass (NoMethodError)
	from /Users/haileekenney/Projects/facter/lib/facter/util/ip.rb:229:in `refresh'
	from /Users/haileekenney/Projects/facter/lib/facter/util/ip.rb:47:in `add_interface_facts'
	from /Users/haileekenney/Projects/facter/lib/facter/interfaces.rb:10:in `<top (required)>'
	from /Users/haileekenney/Projects/facter/lib/facter/util/loader.rb:96:in `load'
	from /Users/haileekenney/Projects/facter/lib/facter/util/loader.rb:96:in `load_file'
	from /Users/haileekenney/Projects/facter/lib/facter/util/loader.rb:47:in `block (2 levels) in load_all'
	from /Users/haileekenney/Projects/facter/lib/facter/util/loader.rb:42:in `each'
	from /Users/haileekenney/Projects/facter/lib/facter/util/loader.rb:42:in `block in load_all'
	from /Users/haileekenney/Projects/facter/lib/facter/util/loader.rb:39:in `each'
	from /Users/haileekenney/Projects/facter/lib/facter/util/loader.rb:39:in `load_all'
	from /Users/haileekenney/Projects/facter/lib/facter/util/collection.rb:115:in `load_all'
	from /Users/haileekenney/Projects/facter/lib/facter.rb:186:in `to_hash'
	from /Users/haileekenney/Projects/facter/lib/facter/application.rb:45:in `run'
	from /Users/haileekenney/Projects/facter/bin/facter:74:in `<top (required)>'
	from /Users/haileekenney/.rvm/gems/ruby-1.9.3-p194/bin/facter:19:in `load'
	from /Users/haileekenney/.rvm/gems/ruby-1.9.3-p194/bin/facter:19:in `<main>'
	from /Users/haileekenney/.rvm/gems/ruby-1.9.3-p194/bin/ruby_noexec_wrapper:14:in `eval'
	from /Users/haileekenney/.rvm/gems/ruby-1.9.3-p194/bin/ruby_noexec_wrapper:14:in `<main>'
```

It looks to me like the problem is happening on line 47 of `ip.rb` with `model.refresh` since this statement is not within the confine.

Hopefully that helps! Let me know if you still need more information.