         self.persistence = SimplePersistence(
             fileSystem: fileSystem,
             schemaVersion: PinsStore.schemaVersion,
-            supportedSchemaVersions: [1],
             statePath: pinsFile,
             prettyPrint: true)
         pinsMap = [:]


    /// The schema version of the resolved file.
    ///
    /// * 2: Package identity.
    /// * 1: Initial version.
    static let schemaVersion: Int = 2

    /// The path to the pins file.
    fileprivate let pinsFile: AbsolutePath

extension PinsStore.Pin: JSONMappable, JSONSerializable, Equatable {
    /// Create an instance from JSON data.
    public init(json: JSON) throws {
        let name: String? = json.get("package")
        let url: String = try json.get("repositoryURL")
        let ref = PackageReference(identity: PackageReference.computeIdentity(packageURL: url), path: url)
        self.packageRef = name.flatMap(ref.with(newName:)) ?? ref
        self.state = try json.get("state")
    }

    /// Convert the pin to JSON.
    public func toJSON() -> JSON {
        return .init([
            "package": packageRef.name.toJSON(),
            "repositoryURL": packageRef.path,
            "state": state,
        ])
    }
