def add_mappers_to_cube_appobject_path():
    """Add "mappers" to `cube_appobject_path` class attribute of CubicWeb
    configuration classes.
    """
    import importlib
    import logging
    LOGGER = logging.getLogger('cubicweb-jsonschema')
    LOGGER.info('adding "mappers" to cube appobjects path')
    for confmod, configclsname in [('etwist.twconfig',
        'AllInOneConfiguration'), ('server.serverconfig',
        'ServerConfiguration'), ('pyramid.config',
        'CubicWebPyramidConfiguration'), ('devtools', 'ApptestConfiguration')]:
        modname = 'cubicweb.' + confmod
        try:
            mod = importlib.import_module(modname)
        except ImportError:
            LOGGER.warning(
                'failed to import %s, "mappers" appobjects will not loaded for this configuration'
                , modname)
            continue
        configcls = getattr(mod, configclsname)
        configcls.cube_appobject_path.add('mappers')
