[illuminati pants (kwlzn/engine/cached_changed)]$ time ./pants -ldebug --enable-v2-engine --changed2-parent=HEAD~2 list
...
DEBUG] changed_request is: ChangedRequest(parent='HEAD~2', diffspec=None, include_dependees='none', fast=False)
DEBUG] Executing: git --git-dir=/Users/kwilson/dev/pants/.git --work-tree=/Users/kwilson/dev/pants diff --name-only HEAD -- /Users/kwilson/dev/pants
DEBUG] Executing: git --git-dir=/Users/kwilson/dev/pants/.git --work-tree=/Users/kwilson/dev/pants diff --name-only HEAD~2...HEAD -- /Users/kwilson/dev/pants
DEBUG] Executing: git --git-dir=/Users/kwilson/dev/pants/.git --work-tree=/Users/kwilson/dev/pants ls-files --other --exclude-standard -- /Users/kwilson/dev/pants
DEBUG] changed files: set([u'src/python/pants/engine/engine.py', u'src/python/pants/build_graph/source_mapper.py', u'src/python/pants/bin/goal_runner.py', u'src/python/pants/scm/change_calculator.py', u'src/python/pants/bin/engine_initializer.py'])
DEBUG] ran 173 scheduling iterations in 1.212234 seconds. there have been 9412 total steps for 5824 total nodes.
DEBUG] changed address: src/python/pants/scm:change_calculator
DEBUG] changed address: src/python/pants/engine:engine
DEBUG] changed address: src/python/pants/bin:bin
DEBUG] changed address: src/python/pants/build_graph:build_graph
...
src/python/pants/build_graph:build_graph
src/python/pants/engine:engine
src/python/pants/bin:bin
src/python/pants/scm:scm