I see https://github.com/pantsbuild/pants/commit/04a0c0aaf7888d2e47c3f332779ceb73ab327de2 pulled in a transitive lib with a deprecated library call.

mateo-2:pants mateo$ ./pants goals
/Users/mateo/dev/pants/build-support/pants_dev_deps.venv/lib/python2.7/site-packages/urllib3/contrib/pyopenssl.py:46: DeprecationWarning: OpenSSL.rand is deprecated - you should use os.urandom instead
  import OpenSSL.SSL

I also see that kris has already reported this upstream: https://github.com/pyca/pyopenssl/issues/674#issuecomment-327986239