how can i debug mine error, git cloned, npm i, npm run dev - and get this error:

npm run dev

[email protected] dev /home/admin_home/Projects/learn/react/firebase/react-redux-firebase-boilerplate webpack-dev-server --config ./webpack/webpack-dev.config.js --watch --colors

events.js:154 throw er; // Unhandled 'error' event ^

Error: listen EADDRINUSE 127.0.0.1:3000 at Object.exports.errnoException (util.js:890:11) at exports._exceptionWithHostPort (util.js:913:20) at Server._dirname.Server.Server._listen2 (net.js:1230:14) at listen (net.js:1266:10) at net.js:1375:9 at GetAddrInfoReqWrap.asyncCallback [as callback] (dns.js:63:16) at GetAddrInfoReqWrap.onlookup [as oncomplete] (dns.js:82:10)

npm ERR! Linux 4.4.0-28-generic npm ERR! argv "/usr/bin/nodejs" "/usr/bin/npm" "run" "dev" npm ERR! node v5.10.1 npm ERR! npm v3.8.8 npm ERR! code ELIFECYCLE npm ERR! [email protected] dev: webpack-dev-server --config ./webpack/webpack-dev.config.js --watch --colors npm ERR! Exit status 1 npm ERR! npm ERR! Failed at the [email protected] dev script 'webpack-dev-server --config ./webpack/webpack-dev.config.js --watch --colors'. npm ERR! Make sure you have the latest version of node.js and npm installed. npm ERR! If you do, this is most likely a problem with the react-redux-firebase-boilerplate package, npm ERR! not with npm itself. npm ERR! Tell the author that this fails on your system: npm ERR! webpack-dev-server --config ./webpack/webpack-dev.config.js --watch --colors npm ERR! You can get information on how to open an issue for this project with: npm ERR! npm bugs react-redux-firebase-boilerplate npm ERR! Or if that isn't available, you can get their info via: npm ERR! npm owner ls react-redux-firebase-boilerplate npm ERR! There is likely additional logging output above.

npm ERR! Please include the following file with any support request: npm ERR! /home/admin_home/Projects/learn/react/firebase/react-redux-firebase-boilerplate/npm-debug.log