postcss-is-pseudo-class: Complex selectors in ':global :is(...)' can not be transformed to an equivalent selector without ':is()'

I’m getting a lot of warnings from postcss of graphiql/graphiql.css

(794:1) postcss-is-pseudo-class: Complex selectors in ‘:global :is(.graphiql-markdown-deprecation, .CodeMirror-hint-information-deprecation-reason, .CodeMirror-info .info-deprecation) code, :global :is(.graphiql-markdown-deprecation, .CodeMirror-hint-information-deprecation-reason, .CodeMirror-info .info-deprecation) pre’ can not be transformed to an equivalent selector without ‘:is()’.

(v2)

[simPod]

I’m using webpack. Followed readme

import { createGraphiQLFetcher } from '@graphiql/toolkit';
import { GraphiQL } from 'graphiql';
import React from 'react';
import ReactDOM from 'react-dom';

import 'graphiql/graphiql.css';

const fetcher = createGraphiQLFetcher({
  url: 'https://my.backend/graphql',
});

ReactDOM.render(<GraphiQL fetcher={fetcher} />, document.body);

but all my css is post processed using postcss:

{ loader: 'postcss-loader', options: postcssConfig }

const postcssConfig = {
  postcssOptions: { plugins: ['postcss-preset-env'] },
  sourceMap: true,
};

so I’m seeing it during build.

[simPod]

@thomasheyenbrock there you go https://github.com/simPod/graphiql-repro/actions/runs/3668664046/jobs/6201950475#step:5:62