Suppress web3 MaxListenersExceededWarning

packages/truffle-core/cli.js

@@ -10,6 +10,12 @@ var OS = require("os");
 
 var command = new Command(require("./lib/commands"));
 
+// Hack to suppress web3 MaxListenersExceededWarning
+// This should be removed when issue is resolved upstream:
+// https://github.com/ethereum/web3.js/issues/1648
+var listeners = process.listeners('warning');
+listeners.forEach(listener => process.removeListener('warning', listener));
+
 var options = {
   logger: console
 };