The LTX-2.3 GGUFs failed with "Cannot copy out of meta tensor; no data!", and
the obvious reading -- parameters the checkpoint lacks -- was wrong.

diffusers 0.38 converts an LTX-2 checkpoint prompt-adaln weights to
prompt_adaln_single.* and audio_prompt_adaln_single.*, while
LTX2VideoTransformer3DModel expects prompt_adaln.* and audio_prompt_adaln.*.
Twelve names, one-to-one, the same tensors. They were present all along, under
a name nobody reconciled, so they never materialised and stayed on meta.

Measured identically on LTX-2.3-10Eros v1.5 and PinkCherry v1.8: 4444 GGUF
tensors, 4186 expected parameters, and after the rename 0 missing and 0
unused on both.

The tempting fix was to initialise those twelve. That would have invented
weights to paper over a rename -- precisely what the surrounding refusal
exists to stop -- so it is NOT what this does. A key is moved only when the
class does not want its current name AND does want the renamed one AND nothing
already occupies the target, which makes it a rename of a tensor the
checkpoint has and never the creation of one it lacks. A test pins that: a
genuinely absent parameter must stay absent and the load must still fail.

The converter is a third-party global, so it is wrapped for the duration of
one from_single_file call and restored in a finally.

Version-robust: 9 pass against the image diffusers 0.38, including the real
checkpoint; against 0.37 the class has no prompt_adaln modules at all, so the
repair is correctly a no-op and that test skips rather than asserting a fact
about someone else is version.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014T3rZnmWyKjWZerwsb27jZ