Error when importing values in pure mode

[simonsmith]

Hello,

I'm opening this issue off the back of - vercel/next.js#10142

It appears that when importing a value from another file when using pure mode an error is encountered. Example:

colors.css

@value blue: #001e62;

module.css

@value blue from "../colors.css";

CLI output:

Selector ":import("../colors.css")" is not pure (pure selectors must contain at least one local class or id)

Repository with a reproducible case - https://github.com/simonsmith/next-js-css-modules-unable-to-use--global-with-css-modules

npm install
npm run dev

Reproduce in tests
Find a test that references :import and add options: { mode: 'pure' } to see the same output in the console:

  {
    should: 'not localize imported alias',
    input: `
      :import(foo) { a_value: some-value; }

      .foo > .a_value { }
    `,
+   options: { mode: 'pure' },
    expected: `
      :import(foo) { a_value: some-value; }

      :local(.foo) > .a_value { }
    `,
  },

My rudimentary debugging has shown that the code checking for import in the class case is not entered, and instead we only see selector used