[Vuejs]-Electron Webpack Vue global variables

Your problem could be the resources path being not correctly resolved from the root directory, hence they’re never really defined.

Possible solution

Assuming your webpack.config.js file is in the same directory as the src/:

{
  loader: 'sass-resources-loader',
  options: {
    resources: path.resolve(__dirname, './src/assets/scss/custom/_variables.scss')
  },
}