Doesn't work with async plugins e.g. TailwindCSS

[ghost]

How to repro

1. Create the two files:

.babelrc

{
  "plugins": [
    ["postcss-template-literals", {
      "plugins": [
        "tailwindcss"
      ]
    }]
  ]
}

tailwind-styles.js

import { css } from 'lit-element';

export const TailwindStyles = css`
  @tailwind base;
  @tailwind components;
  @tailwind utilities;
`;

2. Install deps: npm i --save-dev @babel/cli babel-plugin-postcss-template-literals tailwindcss
3. Execute: npx babel ./tailwind-styles.js

Stacktrace

Error: Use process(css).then(cb) to work with async plugins
    at LazyResult.sync (/mnt/c/Users/domen/Documents/Developer/web/mydiscs.com/node_modules/postcss/lib/lazy-result.js:284:15)
    at LazyResult.stringify (/mnt/c/Users/domen/Documents/Developer/web/mydiscs.com/node_modules/postcss/lib/lazy-result.js:305:10)
    at LazyResult.get (/mnt/c/Users/domen/Documents/Developer/web/mydiscs.com/node_modules/postcss/lib/lazy-result.js:350:19)
    at PluginPass.TaggedTemplateExpression (/mnt/c/Users/domen/Documents/Developer/web/mydiscs.com/node_modules/babel-plugin-postcss-template-literals/index.js:37:67)
    at newFn (/mnt/c/Users/domen/Documents/Developer/web/mydiscs.com/node_modules/@babel/core/node_modules/@babel/traverse/lib/visitors.js:193:21)
    at NodePath._call (/mnt/c/Users/domen/Documents/Developer/web/mydiscs.com/node_modules/@babel/core/node_modules/@babel/traverse/lib/path/context.js:53:20)
    at NodePath.call (/mnt/c/Users/domen/Documents/Developer/web/mydiscs.com/node_modules/@babel/core/node_modules/@babel/traverse/lib/path/context.js:40:17)
    at NodePath.visit (/mnt/c/Users/domen/Documents/Developer/web/mydiscs.com/node_modules/@babel/core/node_modules/@babel/traverse/lib/path/context.js:88:12)
    at TraversalContext.visitQueue (/mnt/c/Users/domen/Documents/Developer/web/mydiscs.com/node_modules/@babel/core/node_modules/@babel/traverse/lib/context.js:118:16)
    at TraversalContext.visitSingle (/mnt/c/Users/domen/Documents/Developer/web/mydiscs.com/node_modules/@babel/core/node_modules/@babel/traverse/lib/context.js:90:19)

[art-bazhin]

Unfortunately Babel doesn't support async plugins yet.
babel/babel#9888