Unable to contact my own XML-RPC server [closed]

edit

What does this error mean? I've gotten it occasionally on different computers but I have no idea how to troubleshoot it.

When I got it on my laptop I think it was because I had recently tried changing the computer's own hostname and something was confused. But in this case i don't think it is due to that...

Any advice on where to look?

$ roscore
... logging to /u/aleeper/.ros/log/d849da10-6097-11e0-b8d4-003048fd842d/roslaunch-bie-19625.log
Checking log directory for disk usage. This may take awhile.
Press Ctrl-C to interrupt
Done checking log file disk usage. Usage is <1GB.

Unable to contact my own XML-RPC server, this is a highly unusual error and should be reported immediately.
My URI is [http://bie:50000/]

Except that isn't the URI, and it changes every time I run roscore ([http://bie:35992/], [http://bie:51667/])

$ env| grep ROS_MASTER_URI
ROS_MASTER_URI=http://localhost:11311