[chaley]

I use this template to create collections.

program:
	globals(serial_number='N4181B1027108');

	if serial_number == 'N4181B1027108' then
		return list_join(
			':@:', 
			list_re($#cbhtags, ',', '^(.*)$', 'CBH Tags: \1'), ',', 
			list_re($authors, '&', '(^.).*', 'Authors: \1'), '&')
	fi;
	if serial_number == 'N4181B5019336' then
		return list_join(
			':@:', 
			list_re($#dthtags, ',', '^(.*)$', 'DTH Tags: \1'), ',',
			list_re($authors, '&', '(^.*)', 'Authors: \1'), '&')
	fi

The problem: no collections are created even though the debug log says the template returned values. Instead I get the following error for all the collections.

category not added to book.device_collections []

I debugged the problem by copying one book to a new library, preserving structure, and setting the debugging title appropriately. After a few trials I found that the problem is caused by create_collections returning false because nothing is in the collections attributes box. The fix: kobo.driver.py line 3681:

    @property
    def create_collections(self):
        return (self.manage_collections and self.supports_bookshelves and self.get_pref('create_collections') and
                                (len(self.collections_columns) > 0 or self.use_collections_template))