bugapp.js

var lib = require('./buglib.js');

lib.on('connect', function() {
  console.log('library ready');
  throw new Error('test throw');
  console.log('done');
});

lib.init(null);

buglib.js

var lib2 = require('./buglib2.js');

var sEvents = {};

module.exports.on = function(event, callback) {
  if (typeof event !== 'string' || typeof callback !== 'function')
    throw new Error('arguments are: String event, Function callback');
  sEvents[event] = callback;
};

module.exports.init = function(params) {
  lib2.init(params, function(op, data) {
    if (sEvents[op])
      return sEvents[op](data);
    if (op === 'error')
      throw data;
  });
};

buglib2.js

var cp = require('child_process');
var fs = require('fs');
var net = require('net');

var sSocketPath = '/tmp/bug.sock';

module.exports.init = function(params, callback) {
  try {
  fs.unlinkSync(sSocketPath);
  } catch (err) {
    if (err.code !== 'ENOENT') throw err;
  }
  var aSrvr = net.createServer(handleConnect);
  aSrvr.listen(sSocketPath, fLoad);
  function fLoad() {
    var aC = cp.spawn('bash', ['-c', 'echo stuff | nc -U '+sSocketPath], {stdio:'inherit'});
    aC.on('exit', function(code, signal) {
      //aSrvr.close();
    });
  }
  function handleConnect(socket) {
    var aTimer = setTimeout(function() {
      console.log('library connected but idle');//. disconnect
      aTimer = null;
    }, 2000);
    socket.on('data', function(data) {
      fMsg(JSON.parse('{"lib":"'+data.lib+'"}'));
    });
    function fMsg(jso) {
      return callback('connect', jso);
    }
  }
};

socket.on('data', function(data) {
  try {
    fMsg(JSON.parse('{"lib":"'+data.lib+'"}'));
  } catch (e) {
    console.log(e);
  }
});

and the exception gets caught!