def pillar_dir(self):
        '''
        Returns the directory of the pillars (repo cache + branch + root)
        '''
        repo_dir = self.repo_dir
        root = self.root
        branch = self.branch
        if branch == 'trunk' or branch == 'base':
            working_dir = os.path.join(repo_dir, 'trunk', root)
            if not os.path.isdir(working_dir):
                log.error('Could not find %s/trunk/%s', self.repo_location, root)
            else:
                return os.path.normpath(working_dir)
        working_dir = os.path.join(repo_dir, 'branches', branch, root)
        if os.path.isdir(working_dir):
            return os.path.normpath(working_dir)
        working_dir = os.path.join(working_dir, 'tags', branch, root)
        if os.path.isdir(working_dir):
            return os.path.normpath(working_dir)
        log.error('Could not find %s/branches/%s/%s', self.repo_location, branch, root)
        return repo_dir
Returns the directory of the pillars (repo cache + branch + root)