Rails6：部署后应用程序显示 SyntaxError: Unexpected token 'export'

Question

The application was working perfectly fine till the latest deployment which started showing error in Developers Tools and on every tab that I try to click in the application.

Deployment is done trough Capistrano

Uncaught SyntaxError: Unexpected token 'export' (at application-00b7157c7.js:44883:1)
(index):261 Uncaught ReferenceError: $ is not defined
    at (index):261:1
(anonymous) @ (index):261
(index):268 Uncaught ReferenceError: $ is not defined
    at (index):268:5
(anonymous) @ (index):268
(index):285 Uncaught ReferenceError: $ is not defined
    at (index):285:5

This is where the error is thrown ->

$.ajaxSetup({
  headers: {
    'X-CSRF-Token': $('meta[name="csrf-token"]').attr('content')
  }
});  

Javascript Version ->

Ext.getVersion('extjs');
constructor {shortVersion: '421883', version: '4.2.1.883'

JQuery is a part of application.js

//
//= require jquery
//= require jquery_ujs
//= require js/bootstrap.min
//= require js/ekko-lightbox.min
//= require jquery.placeholder
//= require jquery-ui

Does anyone know what is causing this?

Answer 1

My Gemfile was at -> jquery-rails (4.4.0) which got upgraded to jquery-rails (4.5.0)during deployment. I changed my Gemfile to restrict the jQuery version gem 'jquery-rails', '4.4.0' which fixed this problem