Skypack dependency on tar is not declared in Yarn package registry

[laptou]

https://yarnpkg.com/package/skypack?files

The package.json file in the Yarn package registry does not appear to be up to date (it is missing the dependency on tar). This means that the skypack package does not work properly with Yarn 2.

[lkrugertogetr]

It's already been resolved in a merged pull request, the new skypack version just has not been pushed to NPM yet. For now you can do the following in .yarnrc.yml:

packageExtensions:
  '@npmcli/metavuln-calculator@*':
    dependencies:
      json-parse-even-better-errors: '*'
  bin-links@*:
    dependencies:
      mkdirp-infer-owner: '*'
  eslint-module-utils@*:
    dependencies:
      eslint-import-resolver-node: '*'
  skypack@*:
    dependencies:
      tar: ^6.1.0
  snowpack@3.8.6:
    dependencies:
      magic-string: '*'

It's likely not all of the above is relevant to you, but this is how I got it working for me. When running yarn start you'll see in the console which package needs which dependency in the yarnrc file. Make sure to run yarn install after editing yarnrc.