fix: xformers use importlib

import builtins

import sys

old_import = builtins.__import__

IMPORT_BLACKLIST = []

if "xformers" not in "".join(sys.argv):

    IMPORT_BLACKLIST.append("xformers")

def import_hook(*args, **kwargs):

    if args[0] in IMPORT_BLACKLIST:

        raise ImportError("Import of %s is blacklisted" % args[0])

    return old_import(*args, **kwargs)

builtins.__import__ = import_hook

    sys.modules["xformers"] = None