If NODE_REPL_HISTORY_FILE was set as $HOME/.node_repl_history pre-v3.0 and if it is empty, running node (post-v3.0) throws.

Twitter conversation about this between @chrisdickinson, @Fishrock123 and myself is here.

Edit: So, I had NODE_REPL_HISTORY_FILE set to $HOME/.node_repl_history but I didn't have the file. Running node created an empty file and since oldHistoryPath was truthy in the call to onread in internal/repl.js, it tried to JSON.parse an empty string and threw.