extensions.php script dies miserably when ext directory is missing

athena% ~/opt/php54/bin/php extensions.php list
Enabled:

Disabled:

Available:

Fatal error: Uncaught exception 'UnexpectedValueException' with message 'RecursiveDirectoryIterator::__construct(/var/www/qi/boards/x3/develop/../ext/): failed to open dir: No such file or directory' in /var/www/qi/boards/x3/includes/extension/manager.php:357
Stack trace:
#0 /var/www/qi/boards/x3/includes/extension/manager.php(357): RecursiveDirectoryIterator->__construct('/var/www/qi/boa...')
#1 /var/www/qi/boards/x3/develop/extensions.php(52): phpbb_extension_manager->all_available()
#2 /var/www/qi/boards/x3/develop/extensions.php(103): list_extensions()
#3

thrown in /var/www/qi/boards/x3/includes/extension/manager.php on line 357

It should simply say that there are no available extensions.

And possibly this needs to be fixed in extension manager.

Note that we do not have ext directory in the repository.