A PostCSS plugin did not pass the `from` option to `postcss.parse`. This may cause imported assets to be incorrectly transformed. If you've recently added a PostCSS plugin that raised this warning, please contact the package author to fix the issue.

我的postcss报了这个异常

    "postcss-color-mix": "^1.1.0",
    "postcss-each": "^1.1.0",
    "postcss-each-variables": "^0.3.0",
    "postcss-for": "^2.1.1",
    "postcss-nested": "^6.0.1",

在配置了postcss-each plugins 的beforeEach后产生的

module.exports = {
  plugins: [
	    require('postcss-each-variables'),
	    require('postcss-nested'),
	    require('postcss-each')({
		      plugins: {
		        beforeEach: [require('postcss-for'), require('postcss-color-mix')]
		      }
	    })
  ]
}