consolidation#497 Fix: Add Basic Self Update Functionality: Add note …

…about sudo

src/SelfUpdateCommand.php

@@ -98,7 +98,7 @@ protected function execute(InputInterface $input, OutputInterface $output)
 
         if (! is_writable($localFilename)) {
             throw new \Exception(
-                $programName . ' update failed: the "' . $localFilename . '" file could not be written'
+                $programName . ' update failed: the "' . $localFilename . '" file could not be written (execute with sudo)'
             );
         }