fix(z-image): Fix padding token shape mismatch for GGUF models #8690
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
GGUF Z-Image models store x_pad_token and cap_pad_token with shape [dim], but diffusers ZImageTransformer2DModel expects [1, dim]. This caused a RuntimeError when loading GGUF-quantized Z-Image models. The fix dequantizes GGMLTensors first (since they don't support unsqueeze), then reshapes to add the batch dimension.
Pfannkuchensack
requested review from
blessedcoolant and
lstein
as code owners
github-actions
bot
added
python
blessedcoolant
approved these changes
Dec 23, 2025
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Summary
Fix shape mismatch when loading GGUF-quantized Z-Image transformer models.
GGUF Z-Image models store
x_pad_tokenandcap_pad_tokenwith shape[3840], but diffusersZImageTransformer2DModelexpects[1, 3840](with batch dimension). This caused aRuntimeErroron Linux systems when loading models likez_image_turbo-Q4_K.gguf.The fix:
unsqueeze)Related Issues / Discussions
Reported by Linux user using:
QA Instructions
z_image_turbo-Q4_K.gguf)RuntimeError: size mismatch for x_pad_tokenerror occursMerge Plan
None, straightforward fix.
Checklist
What's Newcopy (if doing a release after this PR)