I also use the xcodebuild -scmProvider system -resolvePackageDependencies workaround and it's usually enough.
But there is also XCode - File - Add Packages. When I put a public repo URL into the search field, I immediately get "The remote repository could not be accessed" dialog asking for authentication credentials. Proxy credentials won't work there. I don't have any better solution than switching to a proxy-free infrastructure in this case.
DimaHector
Users receive reputation points by contributing quality content to the forums.
Posts include post and replies published on the forums.
Post authors can mark replies as Accepted to indicate successful solutions.
Apple Developer Forums admins can mark replies as Apple Recommended to indicate an approved solution
User for