FSDP Extra State Checkpoint Ignored
A regression in PyTorch 2.3's Distributed Checkpoint (DCP) logic stripped the processing of the `_extra_state` dictionary during `set_model_state_dict`.
A regression in PyTorch 2.
- Root cause
- A regression in PyTorch 2.3's Distributed Checkpoint (DCP) logic stripped the processing of the `_extra_state` dictionary during `set_model_state_dict`.
- Recommended fix
- Upgrade to PyTorch 2.3.1 where the cherry-pick patch #122946 was applied. - pip install --upgrade torch
- How Denpex helps
- Denpex matches FSDP Extra State Checkpoint Ignored across every rank in a distributed run and reports which rank failed first, so you act on the initiating node instead of the loudest one.
What this failure is
FSDP Extra State Checkpoint Ignored is a Model failure seen during ML training runs. A regression in PyTorch 2.3's Distributed Checkpoint (DCP) logic stripped the processing of the `_extra_state` dictionary during `set_model_state_dict`. Common tags: Fsdp, User Report.
Is this what broke your run? Paste your log.
You're reading about FSDP Extra State Checkpoint Ignored. Paste your own crash log or traceback below and get the real root cause for YOUR run, not this generic entry. No account, no card. Logs are masked at ingress and never saved to account history.
Want 14 days on the Scale plan?
Request an evaluation code. A verified workplace organization activates up to 50 diagnoses a day, alerts, history, and follow-up questions. No credit card or automatic subscription.
Why it happens (the mechanism)
Since the `load_state_dict` call does not throw an exception, engineers assume the checkpoint is loaded correctly and blame the data loader or learning rate scheduler for the divergence.
What you'll observe
- Model loads successfully without explicit crashing, but training loss diverges immediately.
- FP8 scaling metadata is lost upon resuming.
Common symptoms and what they mean
| Symptom | Why it happens |
|---|---|
| set_model_state_dict errors on compiled module | A regression in PyTorch 2.3's Distributed Checkpoint (DCP) logic stripped the processing of the `_extra_state` dictionary during `set_model_state_dict`. |
| Transformer Engine Checkpointing Broken on Torch 2.3 | A regression in PyTorch 2.3's Distributed Checkpoint (DCP) logic stripped the processing of the `_extra_state` dictionary during `set_model_state_dict`. |
Which systems are affected
- PyTorch
- FSDP
- TransformerEngine
How to confirm this is the problem
Use this checklist to test the hypothesis against a small reproduction. No single line proves the root cause, so preserve the preceding events and compare one variable at a time.
- ✓Check PyTorch version (`torch.__version__ == '2.3.0'`).
- ✓Inspect the loaded state dictionary to verify the presence of custom extra state metadata.
The fix and the prevention pattern
The root cause is on this page and stays free. A free account adds the exact remediation steps, saved history, and the fix on every entry in the encyclopedia.
Sign up free. Unlock the full analysisNo credit card. Daily allowance follows verified trust tier. Instant access.
Diagnose this failure in VS Code
Select the traceback or open the failed terminal, then run Denpex locally to see the initiating rank, collateral failures, exact fix, and verification command without uploading the log.
Install the free VS Code extensionRoot cause
- A regression in PyTorch 2.3's Distributed Checkpoint (DCP) logic stripped the processing of the `_extra_state` dictionary during `set_model_state_dict`.
The fix and how to prevent it
Evaluate Denpex on your own logs
Request a Scale evaluation code. A verified workplace organization activates 14 days with up to 50 diagnoses a day. Every account keeps its current diagnosis allowance and gets a verification path. No card or automatic subscription.
Don't just read the fix, diagnose your run
The encyclopedia tells you what went wrong. Denpex tells you what went wrong in YOUR training run. With your logs, your config, and your stack.