Prevent repeating parsing of less imports in css modules

Question

I am using css modules together with less preprocessor using webpack.

Each of my css modules starts with

@import (reference) '~lib.less';

to load global variables and mixins.

The (reference) import option prevents any code from lib.less to be actually included in the final css file, however the lib.less file is still parsed once for every module that has the import.

This is a problem because my lib.less is very large and takes around 500ms to parse. That means that for every 20 css modules my build takes 10s longer even if the css modules themselves are tiny.

Is there a way to make less/webpack to parse the lib.css file only once? Cache it or something?

This is my less loader webpack config just in case:

{
    test: /\.less$/,
    include: [SRC_DIR],
    use: [
        'style-loader',
        {
            loader: 'css-loader',
            options: {
                modules: true,
                importLoaders: 2,
                localIdentName: '[name]_[local]_[hash:base64:5]',
            }
        },
        'postcss-loader',
        'less-loader'
    ]
}