title: Xcode suddenly can not get Swift package revision: "Couldn't get revision"
body: <p>I opened a project in Xcode that relies on <code>RxSwift</code> which is included as a Swift package through the builtin Swift package manager.
  It worked fine a couple of week ago when I created the project.</p>
  <p>Now all of a sudden, when trying to build and run my project, I get an error message about that Swift package:</p>
  <p><code>Couldn’t get revision ‘6.5.0^{commit}’</code></p>
  <p>I tried a clean of the build folder, but would still get the same error.</p>
  <p>My internet connection is working fine, so it's not a network issue.</p>
  <p>I am also surprised that Xcode would try to get the revision again since no update of the package in question, <strong>RxSwift</strong> was released between the time building last worked fine and today. So I would assume that whatever is cached locally should still be there and functional.</p>
  <p>So far I could not find any other reports about this error message.</p>