Bump @primer/css from 20.7.1 to 20.8.0 causing issues with postcss-is-pseudo-class

[raivil]

Describe the bug
Bump @primer/css from 20.7.1 to 20.8.0 causing issues with postcss-is-pseudo-class.
I'm not sure if this is a primer issue or postcss-is-pseudo-class issue. If this does not belong here, let me know and I'll reopen on the proper location.

"@csstools/postcss-is-pseudo-class@^2.0.7":
postcss-scss@^4.0.5:
@primer/css from 20.7.1 to 20.8.0


gem "primer_view_components", "~> 0.0.116"
gem "shakapacker", "6.5.4"

To Reproduce

Expected behavior
No warnings :)

Screenshots

Additional context

Compiled with problems:X

WARNING in ./app/assets/stylesheets/application.scss (./app/assets/stylesheets/application.scss.webpack[javascript/auto]!=!./node_modules/css-loader/dist/cjs.js??ruleSet[1].rules[3].use[1]!./node_modules/postcss-loader/dist/cjs.js??ruleSet[1].rules[3].use[2]!./node_modules/sass-loader/dist/cjs.js??ruleSet[1].rules[3].use[3]!./app/assets/stylesheets/application.scss)

Module Warning (from ./node_modules/postcss-loader/dist/cjs.js):
Warning

(28425:1) postcss-is-pseudo-class: Complex selectors in ':is(.Truncate > .Truncate-text) + .Truncate-text' can not be transformed to an equivalent selector without ':is()'.


WARNING in ./app/assets/stylesheets/application.scss (./app/assets/stylesheets/application.scss.webpack[javascript/auto]!=!./node_modules/css-loader/dist/cjs.js??ruleSet[1].rules[3].use[1]!./node_modules/postcss-loader/dist/cjs.js??ruleSet[1].rules[3].use[2]!./node_modules/sass-loader/dist/cjs.js??ruleSet[1].rules[3].use[3]!./app/assets/stylesheets/application.scss)

Module Warning (from ./node_modules/postcss-loader/dist/cjs.js):
Warning

(28425:1) postcss-is-pseudo-class: Complex selectors in ':is(.Truncate > .Truncate-text) + .Truncate-text' can not be transformed to an equivalent selector without ':is()'.

[danielnc]

I am having the same issue

[simurai]

Thanks for reporting. 🙇 Are you using postcss-is-pseudo-class to make the CSS more backwards compatible? It seems browser support for is() is pretty good.

Anyways, we might not really need is() just yet. So in primer/view_components#1722 we disabled the is() selector. We still need to wait for @primer/view-components@0.0.117 until we can update primer/css.