From b19cbe925be361d229f0fe03435affe4a2717f37 Mon Sep 17 00:00:00 2001 From: Xuan-Son Nguyen Date: Fri, 28 Aug 2026 11:46:30 +0200 Subject: [PATCH] convert: prevent ndarray conversion in LazyChunkedTensor (#27869) --- gguf-py/gguf/gguf_writer.py | 7 ++++++- gguf-py/gguf/lazy.py | 4 ++++ 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/gguf-py/gguf/gguf_writer.py b/gguf-py/gguf/gguf_writer.py index 1f309ad2ea..d95fe9b1ac 100644 --- a/gguf-py/gguf/gguf_writer.py +++ b/gguf-py/gguf/gguf_writer.py @@ -467,10 +467,15 @@ class GGUFWriter: shard_bar.reset(total=(total if total > 0 else None)) # relying on the fact that Python dicts preserve insertion order (since 3.7) - for ti in tensors.values(): + for name, ti in tensors.items(): assert ti.tensor is not None # can only iterate once over the tensors assert ti.tensor.nbytes == ti.nbytes + start = fout.tell() ti.tensor.tofile(fout) + # a short write here would only surface as a corrupt file at load time + if fout.tell() - start != ti.nbytes: + raise ValueError( + f"tensor {name!r} wrote {fout.tell() - start} bytes, expected {ti.nbytes}") if shard_bar is not None: shard_bar.update(ti.nbytes) if bar is not None: diff --git a/gguf-py/gguf/lazy.py b/gguf-py/gguf/lazy.py index 6a0aee8811..a39f223215 100644 --- a/gguf-py/gguf/lazy.py +++ b/gguf-py/gguf/lazy.py @@ -251,6 +251,10 @@ class LazyChunkedTensor: def numpy(self) -> LazyChunkedTensor: return self + def __array__(self, *args, **kwargs): + # numpy would otherwise make a 1-element object array of self, and write 8 bytes + raise TypeError("LazyChunkedTensor cannot become an ndarray, it is written in chunks") + def quantize(self, qtype: Any) -> LazyChunkedTensor: from .constants import GGMLQuantizationType from .quants import QuantError, quant_shape_to_byte_shape