PEFT Models are not resuming from checkpoint as expected.
### System Info

transformers : 4.30

### Who can help?

@llohann-speranca @younesbelkada 

### Information

- [ ] The official example scripts
- [ ] My own modified scripts

### Tasks

- [ ] An officially supported task in the `examples` folder (such as GLUE/SQuAD, ...)
- [ ] My own task or dataset (give details below)

### Reproduction

Please try below code snippet as per example:
```python
import os
from transformers import TrainingArguments
from datasets import load_dataset
from trl import SFTTrainer
from peft import LoraConfig

dataset = load_dataset("imdb", split="train")
output_dir = "test"

training_args = TrainingArguments(
    output_dir=output_dir,
    per_device_train_batch_size=1,
    per_device_eval_batch_size=1,
    max_steps=5,
    save_steps=1,
    save_strategy='steps'
)

peft_config = LoraConfig(
    r=16,
    lora_alpha=32,
    lora_dropout=0.05,
    bias="none",
    task_type="CAUSAL_LM",
)

trainer = SFTTrainer(
    "EleutherAI/gpt-neo-125m",
    train_dataset=dataset,
    args=training_args,
    dataset_text_field="text",
    peft_config=peft_config
)
trainer.train()
trainer.save_model(os.path.join(output_dir, "checkpoint-1"))
trainer.train()
```

For the above code snippet I have pulled @llohann-speranca's resume from checkpoint repo then replaced the installed transformers repo.

Inital version of trainer.train() is working without any issues.
As mentioned that I have overridden the model by using trainer.save_model(path of saved model).

For resuming from checkpoint i have updated num of epochs much higher than previous one.
while passing as trainer.train(resume from checkpoint=True) then it is showing as can't find a valid checkpoint.
Also while passing as trainer.train(resume from checkpoint = path of saved model)then it is showing as can't find a valid checkpoint.

The same issue persists in the transformers source installed version as well.


### Expected behavior

The model should be resumed from checkpoint.
Hi @techthiyanes 
Thank you very much for double checking, here are the snippets that I have ran and they work fine on my end using the branh you have mentioned:

<details><summary>Without `resume_from_checkpoint`</summary>

```python

import os
from transformers import TrainingArguments
from datasets import load_dataset
from trl import SFTTrainer
from peft import LoraConfig

dataset = load_dataset("imdb", split="train")
output_dir = "test"

training_args = TrainingArguments(
    output_dir=output_dir,
    per_device_train_batch_size=1,
    per_device_eval_batch_size=1,
    max_steps=5,
    save_steps=1,
    save_strategy='steps'
)

peft_config = LoraConfig(
    r=16,
    lora_alpha=32,
    lora_dropout=0.05,
    bias="none",
    task_type="CAUSAL_LM",
)

trainer = SFTTrainer(
    "EleutherAI/gpt-neo-125m",
    train_dataset=dataset,
    args=training_args,
    dataset_text_field="text",
    peft_config=peft_config
)
trainer.train()
trainer.save_model(os.path.join(output_dir, "checkpoint-1"))
trainer.train(resume_from_checkpoint=True)
```

</details>

<details><summary>With `resume_from_checkpoint`</summary>

```python

import os
from transformers import TrainingArguments
from datasets import load_dataset
from trl import SFTTrainer
from peft import LoraConfig

dataset = load_dataset("imdb", split="train")
output_dir = "test"

training_args = TrainingArguments(
    output_dir=output_dir,
    per_device_train_batch_size=1,
    per_device_eval_batch_size=1,
    max_steps=5,
    save_steps=1,
    save_strategy='steps'
)

peft_config = LoraConfig(
    r=16,
    lora_alpha=32,
    lora_dropout=0.05,
    bias="none",
    task_type="CAUSAL_LM",
)

trainer = SFTTrainer(
    "EleutherAI/gpt-neo-125m",
    train_dataset=dataset,
    args=training_args,
    dataset_text_field="text",
    peft_config=peft_config
)
trainer.train()
trainer.save_model(os.path.join(output_dir, "checkpoint-1"))
trainer.train()
```

</details>

Can you elaborate more on:

> For resuming from checkpoint i have updated num of epochs much higher than previous one.
while passing as trainer.train(resume from checkpoint=True) then it is showing as can't find a valid checkpoint.
Also while passing as trainer.train(resume from checkpoint = path of saved model)then it is showing as can't find a valid checkpoint.

Thanks! <|||||>> ```python
> ```python
> trainer.train(resume_from_checkpoint=True)
> ```
> 
> 
>     
>       
>     
> 
>       
>     
> 
>     
>   
> ```

So far I'm able to replicate the issue.

Steps I have followed:

Libaries Installed:
! pip install datasets  peft evaluate
!pip install git+https://github.com/huggingface/transformers

Clone PEFT resume from chekpoint branch:
!git clone https://github.com/llohann-speranca/transformers.git -b fix-resume-checkpoint-for-peftmodel

Replace this folder where the transformers library installed:
!cp -r /content/transformers /usr/local/lib/python3.10/dist-packages/transformers

Restart the run time.

Then below code snippet:

import os
from transformers import TrainingArguments
from datasets import load_dataset
from trl import SFTTrainer
from peft import LoraConfig

dataset = load_dataset("imdb", split="train")
output_dir = "test"

training_args = TrainingArguments(
    output_dir=output_dir,
    per_device_train_batch_size=1,
    per_device_eval_batch_size=1,
    max_steps=5,
    save_steps=1,
    save_strategy='steps'
)

peft_config = LoraConfig(
    r=16,
    lora_alpha=32,
    lora_dropout=0.05,
    bias="none",
    task_type="CAUSAL_LM",
)

trainer = SFTTrainer(
    "EleutherAI/gpt-neo-125m",
    train_dataset=dataset,
    args=training_args,
    dataset_text_field="text",
    peft_config=peft_config
)
trainer.train()
trainer.save_model(os.path.join(output_dir, "checkpoint-1"))
trainer.train(resume_from_checkpoint=True)

![image](https://github.com/huggingface/transformers/assets/25921035/8b2230d6-14a7-43f6-b8d3-d6df9d94704d)

@younesbelkada  @@llohann-speranca

I guess you would have run the snippet via already from modified trainer code that resides internally.

Could you please try running the code that is downloaded from git on specific branch?

Thanks a lot on your effort on validating this.
<|||||>Hi @techthiyanes 
Can you try to install `transformers` with the following command ?
```bash
pip install git+https://github.com/llohann-speranca/transformers.git@fix-resume-checkpoint-for-peftmodel
```
The line 1991 of your traceback doesn't match with the line 1991 of the fork: https://github.com/llohann-speranca/transformers/blob/e01a4aa77073b847b9451c92c2df718a67960df1/src/transformers/trainer.py#L1991 so I believe you did not installed correctly transformers from that branch<|||||>> ```shell
> pip install git+https://github.com/llohann-speranca/transformers.git@fix-resume-checkpoint-for-peftmodel
> ```

Thanks a lot on finding and fixing to help this issue.
Now I am able to resume from checkpoint. It's working for classification and seq2seq models as well.