PR nuxt#9671 upgraded PostCSS to version 8.

This module allows opting-in to postcss@8 with nuxt 2 projects.

• Ensures supported nuxt version is used (>= 2.15.3 < 2.16.0)
• Forces to use correct dependencies using __NUXT_PREPATHS__
• Will self-adjust integration method based on future nuxt versions
• Use autoprefixer instead of postcss-preset-env

Install @nuxt/postcss8 as devDependency of project:

yarn add --dev @nuxt/postcss8
# or
npm i -D @nuxt/postcss8

Add @nuxt/postcss8 to buildModules in nuxt.config:

// nuxt.config
export default {
  buildModules: [
    '@nuxt/postcss8'
  ]
}

If you have a nuxt module that requires postcss@8, install @nuxt/postcss8 as dependency of module:

yarn add postcss@8 @nuxt/postcss8
# or
npm i postcss@8 @nuxt/postcss8

Inside module:

export default async function() {
  await this.addModule('@nuxt/postcss8')
}

MIT License