gonzo:[~/src/snowchain][master]$ ./pants
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 1679k  100 1679k    0     0  3319k      0 --:--:-- --:--:-- --:--:-- 3319k
New python executable in /Users/benjyw/.cache/pants/setup/bootstrap-Darwin-x86_64/pants.j9wjpi/install/bin/python2.7
Also creating executable in /Users/benjyw/.cache/pants/setup/bootstrap-Darwin-x86_64/pants.j9wjpi/install/bin/python
Installing setuptools, pip, wheel...done.
You are using pip version 7.1.0, however version 9.0.1 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
Collecting pantsbuild.pants==1.4.0.dev27
  Using cached pantsbuild.pants-1.4.0.dev27-cp27-none-macosx_10_10_intel.whl
<snip>
Collecting cryptography>=1.3.4 (from requests[security]<2.19,>=2.5.0->pantsbuild.pants==1.4.0.dev27)
  Using cached cryptography-2.1.4.tar.gz
    Complete output from command python setup.py egg_info:
    error in cryptography setup command: Invalid environment marker: platform_python_implementation != 'PyPy'
    
    ----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /private/var/folders/4t/btjfp2sn7pldd1h5_fn6mwxc0000gn/T/pip-build-vfmERj/cryptography
./pants: line 84: /Users/benjyw/.cache/pants/setup/bootstrap-Darwin-x86_64/1.4.0.dev27/bin/pants: No such file or directory