Help Building nupic.core (Yosemite)

Engineering NuPIC
3

I ran and re-ran the pip uninstall and got this error on both uninstall and install:

Exception:

Traceback (most recent call last):
  File "/Library/Python/2.7/site-packages/pip/basecommand.py", line 215, in main
    status = self.run(options, args)
  File "/Library/Python/2.7/site-packages/pip/commands/install.py", line 299, in run
    requirement_set.prepare_files(finder)
  File "/Library/Python/2.7/site-packages/pip/req/req_set.py", line 370, in prepare_files
    ignore_dependencies=self.ignore_dependencies))
  File "/Library/Python/2.7/site-packages/pip/req/req_set.py", line 458, in _prepare_file
    req_to_install, finder)
  File "/Library/Python/2.7/site-packages/pip/req/req_set.py", line 397, in _check_skip_installed
    req_to_install.check_if_exists()
  File "/Library/Python/2.7/site-packages/pip/req/req_install.py", line 1004, in check_if_exists
    self.req.name
  File "/Library/Python/2.7/site-packages/pip/_vendor/pkg_resources/__init__.py", line 535, in get_distribution
    dist = get_provider(dist)
  File "/Library/Python/2.7/site-packages/pip/_vendor/pkg_resources/__init__.py", line 415, in get_provider
    return working_set.find(moduleOrReq) or require(str(moduleOrReq))[0]
  File "/Library/Python/2.7/site-packages/pip/_vendor/pkg_resources/__init__.py", line 943, in require
    needed = self.resolve(parse_requirements(requirements))
  File "/Library/Python/2.7/site-packages/pip/_vendor/pkg_resources/__init__.py", line 834, in resolve
    raise VersionConflict(dist, req).with_context(dependent_req)
ContextualVersionConflict: (pytest 2.5.1 (/Users/cogmission/Library/Python/2.7/lib/python/site-packages), Requirement.parse('pytest==2.4.2'), set(['nupic']))

???

EDIT: First it did uninstall though