When you debug a node session and you stop in the debugger, the Variables view shows "Data collection ...", but the data never arrives:
This happens with node version 0.10.34 and 0.10.35 from node.
I had the same problem with John's brain after installing Node v.6.0.0.
Decision:
Install nvm (node ββversion manager).
Debug your programs using the Node version specified in v.5.8.0
Update to 2016.2, and this problem has been fixed. Now you can use node 6 with debugging and work just fine.