特定のパッケージっていうのは https://github.com/uber/mockolo かな？私の環境だと問題なかったです。わからないけど https://stackoverflow.com/questions/71506588/what-is-swiftpm-spmrepositoryerror-error-5 の回答があってそうです。

GitHub - uber/mockolo: Efficient Mock Generator for Swift

Efficient Mock Generator for Swift. Contribute to uber/mockolo development by creating an account on GitHub.

What is "SwiftPM.SPMRepositoryError error 5"?

I've searched Apple's documentation, open source projects, and Google, and I cannot seem to find any information about SwiftPM.SPMRepositoryError error 5. Heck, I can't even find information about