     override func log(entry : LogManager.LogEntry) -> Void {
         mutex.synchronized {
             if self.daysBetween(entry.timestamp, and: self.mostRecentLog!) > 0 {
-                try! self.cleanup(entry.timestamp)
+                self.cleanup(entry.timestamp)
             }
 
             self.mostRecentLog = entry.timestamp


        // initial cleanup

        try cleanup(NSDate())
    }

    // MARK: internal

        return files.filter({try! nameAndDate($0.lastPathComponent!).name != nil}).map({ ($0, try! nameAndDate($0.lastPathComponent!).date!) })
    }

    func cleanup(now : NSDate) {
        // copy current log

        if mostRecentLog != nil && daysBetween(now, and: mostRecentLog!) > 0 {
