From b91c063cdfdf4758cdf51866d866412fa6d7ffbe Mon Sep 17 00:00:00 2001
From: Aaron Meese <aaron@meese.dev>
Date: Mon, 16 Mar 2026 16:26:03 -0400
Subject: [PATCH] fix: accept **kwargs in Params4bit and Int8Params
 constructors
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accelerate's set_module_tensor_to_device passes the old parameter's
__dict__ as **kwargs when reconstituting quantized parameters.
Transformers >= 5.x adds _is_hf_initialized to every parameter's
__dict__, but Params4bit.__new__ and Int8Params.__new__ had fixed
signatures — causing TypeError on any model loaded with
BitsAndBytesConfig + device_map="auto".

Add **kwargs to both constructors so unexpected attributes are silently
ignored instead of crashing.
---
 bitsandbytes/nn/modules.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/bitsandbytes/nn/modules.py b/bitsandbytes/nn/modules.py
index ff8ce9c3d..54506f41d 100644
--- a/bitsandbytes/nn/modules.py
+++ b/bitsandbytes/nn/modules.py
@@ -222,6 +222,7 @@ def __new__(
         quant_storage: torch.dtype = torch.uint8,
         module: Optional["Linear4bit"] = None,
         bnb_quantized: bool = False,
+        **kwargs,
     ) -> "Params4bit":
         if data is None:
             data = torch.empty(0)
@@ -680,6 +681,7 @@ def __new__(
         has_fp16_weights=False,
         CB: Optional[torch.Tensor] = None,
         SCB: Optional[torch.Tensor] = None,
+        **kwargs,
     ):
         if data is None:
             data = torch.empty(0)