While this has cleaned up a number of issues with executing tests and properly isolating the state across runs, it has also increased I/O by rapidly creating / deleting test directories and files.
On Windows (inside of VMWare Fusion), suite execution time has risen from 6:54 to 8:12 – an increase of 1:16 (about 18%). On OSX 10.9 (not virtualized), suite execution time has risen from 2:12 to 2:37 (about 19%).
The solution may be to lazily create `confdir` instead of initializing it each run with `tmpdir` in `spec_helper.rb`. Another potential solution is to find where settings are loaded from disk unnecessarily, and to stub these calls via `Puppet.settings.stubs(:use)`