roscore bug Errno8

edit

I've got a new installation of ROS Indigo on OSX Yosemite. In a terminal when I enter: roscore I get the error message:

... 76, in is_local_address local_addresses = ['localhost'] + get_local_addresses() File "/opt/ros/indigo/lib/python2.7/site-packages/rosgraph/network.py", line 240, in get_local_addresses local_addrs = [host[4][0] for host in socket.getaddrinfo(socket.gethostname(), 0, socket.AF_INET, 0, socket.SOL_TCP)] gaierror: [Errno 8] nodename nor servname provided, or not known

printenv | grep ROS prints out:

ROS_ROOT=/opt/ros/indigo/share/ros
ROS_PACKAGE_PATH=/opt/ros/indigo/share:/opt/ros/indigo/stacks
ROS_MASTER_URI=http://localhost:11311
ROS_HOSTNAME=localhost
ROSLISP_PACKAGE_DIRECTORIES=
ROS_DISTRO=indigo
ROS_IP=0.0.0.0
ROS_ETC_DIR=/opt/ros/indigo/etc/ros

I have no /etc/hosts file. ping localhost works. I'm just trying to run ROS master and clients locally on my Mac. Thanks!