Remove logic to skip checkpoint save if checkpoint exists
based on current test failure, looks like this requires changes in MCore as well to handle and existing dist ckpt dir. i'd say we should make that change first before merging this > based on current test failure, looks like this requires changes in MCore as well to handle and existing dist ckpt dir. i'd say we should make that change first before merging this

How can I check the failing tests? The only failing job I see is this one but it doesn't have any useful info: https://github.com/NVIDIA/NeMo/actions/runs/11958751953/job/33339441430?pr=11362

Regardless of the failure, I would recommend ensuring that on the NeMo side the checkpointing logic ensures that we don't save twice to the same directory, otherwise that could lead to silent errors.

We did it for NeMo 1.0 and currently all such circumstances (saving twice to the same dir) are explicitly treated as an error which I believe leads to a better experiments handling from a user perspective from that link, go to the Summary, and see the 'Failed jobs'. This [one](https://github.com/NVIDIA/NeMo/actions/runs/11958751953/job/33339268893) is failing.
> I would recommend ensuring that on the NeMo side the checkpointing logic ensures that we don't save twice to the same directory, otherwise that could lead to silent errors.

You're right, I completely agree. Currently on main, async save will crash if the dir exists. Non-async save will just print warning and skip saving. Looks like this change is exposing that problem in one of the tests. 

What I don't understand is why we aren't running the PTL logic that appends a version counter ([1](https://github.com/Lightning-AI/pytorch-lightning/blob/master/src/lightning/pytorch/callbacks/model_checkpoint.py#L661-L665), [2](https://github.com/Lightning-AI/pytorch-lightning/blob/master/src/lightning/pytorch/callbacks/model_checkpoint.py#L685-L689)) >Currently on main, async save will crash if the dir exists. Non-async save will just print warning and skip saving. Looks like this change is exposing that problem in one of the tests.

With this PR, both async and synchronous checkpointing will error if we try to save to an existing directory, which I think is what we want, right? In that case, maybe we can just update the test to save to different directories ran the failing test locally with your changes, I think FSDPStrategy is missing `import os` so removing previous last checkpoint will fail: https://github.com/NVIDIA/NeMo/blob/main/nemo/lightning/pytorch/strategies/fsdp_strategy.py#L198-L205 > ran the failing test locally with your changes, I think FSDPStrategy is missing `import os` so removing previous last checkpoint will fail: https://github.com/NVIDIA/NeMo/blob/main/nemo/lightning/pytorch/strategies/fsdp_strategy.py#L198-L205

Hm yeah, I noticed that and tried to update but looks like there was a problem with pushing my changes. Let me try again [🤖]: Hi @ashors1 👋,

We wanted to let you know that a [CICD pipeline](https://github.com/NVIDIA/NeMo/actions/runs/12001688420) for this PR just finished successfully

So it might be time to merge this PR or get some approvals

I'm just a bot so I'll leave it you what to do next.

//cc @pablo-garay @ko3n1g <!-- pylint-output-strict-mode-false -->

beep boop 🤖: 🙏 The following files have warnings. In case you are familiar with these, please try helping us to improve the code base.

---

Your code was analyzed with PyLint. The following annotations have been identified:

```
************* Module nemo.lightning.io.pl
nemo/lightning/io/pl.py:82:0: C0301: Line too long (130/119) (line-too-long)
nemo/lightning/io/pl.py:58:0: C0115: Missing class docstring (missing-class-docstring)
nemo/lightning/io/pl.py:64:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/lightning/io/pl.py:73:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/lightning/io/pl.py:282:4: C0116: Missing function or method docstring (missing-function-docstring)
************* Module nemo.lightning.pytorch.strategies.fsdp_strategy
nemo/lightning/pytorch/strategies/fsdp_strategy.py:86:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/lightning/pytorch/strategies/fsdp_strategy.py:92:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/lightning/pytorch/strategies/fsdp_strategy.py:117:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/lightning/pytorch/strategies/fsdp_strategy.py:143:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/lightning/pytorch/strategies/fsdp_strategy.py:152:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/lightning/pytorch/strategies/fsdp_strategy.py:162:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/lightning/pytorch/strategies/fsdp_strategy.py:170:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/lightning/pytorch/strategies/fsdp_strategy.py:178:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/lightning/pytorch/strategies/fsdp_strategy.py:199:4: C0116: Missing function or method docstring (missing-function-docstring)

-----------------------------------
Your code has been rated at 9.47/10
```

---

Thank you for improving NeMo's documentation! <!-- pylint-output-strict-mode-false -->

beep boop 🤖: 🙏 The following files have warnings. In case you are familiar with these, please try helping us to improve the code base.

---

Your code was analyzed with PyLint. The following annotations have been identified:

```
************* Module nemo.lightning.io.pl
nemo/lightning/io/pl.py:82:0: C0301: Line too long (130/119) (line-too-long)
nemo/lightning/io/pl.py:58:0: C0115: Missing class docstring (missing-class-docstring)
nemo/lightning/io/pl.py:64:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/lightning/io/pl.py:73:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/lightning/io/pl.py:282:4: C0116: Missing function or method docstring (missing-function-docstring)
************* Module nemo.lightning.pytorch.strategies.fsdp_strategy
nemo/lightning/pytorch/strategies/fsdp_strategy.py:86:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/lightning/pytorch/strategies/fsdp_strategy.py:92:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/lightning/pytorch/strategies/fsdp_strategy.py:117:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/lightning/pytorch/strategies/fsdp_strategy.py:143:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/lightning/pytorch/strategies/fsdp_strategy.py:152:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/lightning/pytorch/strategies/fsdp_strategy.py:162:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/lightning/pytorch/strategies/fsdp_strategy.py:170:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/lightning/pytorch/strategies/fsdp_strategy.py:178:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/lightning/pytorch/strategies/fsdp_strategy.py:199:4: C0116: Missing function or method docstring (missing-function-docstring)

-----------------------------------
Your code has been rated at 9.47/10
```

---

Thank you for improving NeMo's documentation! [🤖]: Hi @ashors1 👋,

We wanted to let you know that a [CICD pipeline](https://github.com/NVIDIA/NeMo/actions/runs/12014964851) for this PR just finished successfully

So it might be time to merge this PR or get some approvals

I'm just a bot so I'll leave it you what to do next.

//cc @pablo-garay @ko3n1g
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