Firebase security rules: "ruleset uses old version", what is current version?

Question

firebase --version 8.4.1

with Firebase init I created some files.

Now firebase deploy is complaining about firebase.storage. The error message is:

Ruleset uses old version (version [1]). Please update to the latest version (version [2]).

What is wrong with it?

firebase deploy
deploying database, storage, firestore, functions, hosting 
database:   checking rules syntax... 
database: rules syntax for database $db is valid 
firebase.storage: checking storage.rules for compilation errors... 
undefined:undefined - Ruleset uses old version (version
   [1]). Please update to the latest version (version [2]).
firebase.storage: rules file storage.rules compiled successfully

cat storage.rules

service firebase.storage {
  match /b/{bucket}/o {
    match /{allPaths=**} {
      allow read, write: if request.auth!=null;
    }
  }
}

Answer 1

You should be using security rules version 2 going forward. Note the first line:

rules_version = '2';
service firebase.storage {
  match /b/{bucket}/o {
    match /{allPaths=**} {
      allow read, write: if request.auth!=null;
    }
  }
}