Error Deploying with webpack on Heroku

Hi, im trying to deploy a Laravel 5.4 application on heroku and everything works fine except when assets are about to compile running 'npm run prod' configured on packaje.json with the postinstall key to run automatically.

Here is my webpack.mix.js file:

mix.js('resources/assets/js/app.js', 'public/js') .sass('resources/assets/sass/app.scss', 'public/css');

mix.copy('./node_modules/bootstrap-switch/dist/js/bootstrap-switch.js', 'public/js'); mix.copy('./node_modules/bootstrap-switch/dist/css/bootstrap3/bootstrap-switch.css', 'public/css'); mix.copy('./node_modules/animate.css/animate.css', 'public/css');

mix.copy('./node_modules/sweetalert/dist/sweetalert.css', 'public/css'); mix.copy('./node_modules/sweetalert/dist/sweetalert.min.js', 'public/js');

And here is the error that i'm getting on heroku;

@ production /tmp/build_e047d1635df922533f1138aaed49ec27 remote: > cross-env NODE_ENV=production node_modules/webpack/bin/webpack.js --progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js remote: remote: 95% emitting DONE Compiled successfully in 20810ms7:43:16 PM remote: remote: fs.js:907 remote: return binding.stat(pathModule._makeLong(path)); remote: ^ remote: remote: Error: ENOENT: no such file or directory, stat '/tmp/build_e047d1635df922533f1138aaed49ec27/node_modules/bootstrap-switch/dist/js/bootstrap-switch.js' remote: at Object.fs.statSync (fs.js:907:18)