Error: PostCSS plugin postcss-discard-comments requires PostCSS 8.

ERROR Error: PostCSS plugin postcss-discard-comments requires PostCSS 8.
Migration guide for end-users:
https://github.com/postcss/postcss/wiki/PostCSS-8-for-end-users
Error: PostCSS plugin postcss-discard-comments requires PostCSS 8.
Migration guide for end-users:
https://github.com/postcss/postcss/wiki/PostCSS-8-for-end-users
at Processor.normalize (C:\Users\Administrator\Desktop\11.24\my-project\node_modules\postcss\lib\processor.js:167:15)

执行npm run build:h5 出现的这个问题