message: Change debugging option for vscode users
diff: @@ -281,8 +281,8 @@ module.exports = function(opts = {}) {
  // ====================
  let devtool = false;
  if (!options.isProduction) {
  - if (process.env.SLOW_BUILD_SPEED) {
  - devtool = 'source-map';
  + if (process.env.VSCODE_DEBUG) {
  + devtool = 'cheap-module-source-map';
  } else {
  devtool = 'cheap-module-eval-source-map';
  }
  