install tensorflow just works

gistfile1.txt

$ virtualenv --python /usr/bin/python2.7 --system-site-packages env
Running virtualenv with interpreter /usr/bin/python2.7
New python executable in /Users/jaraco/env/bin/python
Installing setuptools, pip, wheel...done.
$ env/bin/pip install -U tensorflow
Collecting tensorflow
  Downloading tensorflow-1.0.0-cp27-cp27m-macosx_10_11_x86_64.whl (39.3MB)
    100% |████████████████████████████████| 39.4MB 26kB/s 
Collecting mock>=2.0.0 (from tensorflow)
  Using cached mock-2.0.0-py2.py3-none-any.whl
Requirement already up-to-date: six>=1.10.0 in ./env/lib/python2.7/site-packages (from tensorflow)
Collecting protobuf>=3.1.0 (from tensorflow)
  Downloading protobuf-3.2.0-py2.py3-none-any.whl (360kB)
    100% |████████████████████████████████| 368kB 1.9MB/s 
Collecting numpy>=1.11.0 (from tensorflow)
  Downloading numpy-1.12.0-cp27-cp27m-macosx_10_6_intel.macosx_10_9_intel.macosx_10_9_x86_64.macosx_10_10_intel.macosx_10_10_x86_64.whl (4.4MB)
    100% |████████████████████████████████| 4.4MB 277kB/s 
Requirement already up-to-date: wheel in ./env/lib/python2.7/site-packages (from tensorflow)
Collecting funcsigs>=1; python_version < "3.3" (from mock>=2.0.0->tensorflow)
  Using cached funcsigs-1.0.2-py2.py3-none-any.whl
Collecting pbr>=0.11 (from mock>=2.0.0->tensorflow)
  Using cached pbr-1.10.0-py2.py3-none-any.whl
Requirement already up-to-date: setuptools in ./env/lib/python2.7/site-packages (from protobuf>=3.1.0->tensorflow)
Requirement already up-to-date: appdirs>=1.4.0 in ./env/lib/python2.7/site-packages (from setuptools->protobuf>=3.1.0->tensorflow)
Requirement already up-to-date: packaging>=16.8 in ./env/lib/python2.7/site-packages (from setuptools->protobuf>=3.1.0->tensorflow)
Requirement already up-to-date: pyparsing in ./env/lib/python2.7/site-packages (from packaging>=16.8->setuptools->protobuf>=3.1.0->tensorflow)
Installing collected packages: funcsigs, pbr, mock, protobuf, numpy, tensorflow
  Found existing installation: numpy 1.8.0rc1
    Not uninstalling numpy at /System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python, outside environment /Users/jaraco/env
Successfully installed funcsigs-1.0.2 mock-2.0.0 numpy-1.12.0 pbr-1.10.0 protobuf-3.2.0 tensorflow-1.0.0
$ env/bin/python -c "import setuptools"
$