Can't load pegasus models.
Hi, 

I've tried uploading Peagsus from PreTrainedModel and PreTrainedTokenizer but run into KeyError, I have transformers 3.0.2 - any idea why that might be happening?
Not sure what you mean here. Can you please post the traceback and the code that resulted in the error ?<|||||>This is what I got:
```
KeyError                                  Traceback (most recent call last)

<ipython-input-18-eb1fb8795ed4> in <module>()
      2 from transformers import AutoTokenizer, AutoModelWithLMHead
      3 
----> 4 tokenizer = AutoTokenizer.from_pretrained("google/pegasus-multi_news")
      5 
      6 cla = AutoModelWithLMHead.from_pretrained("google/pegasus-multi_news")

1 frames

/usr/local/lib/python3.6/dist-packages/transformers/tokenization_auto.py in from_pretrained(cls, pretrained_model_name_or_path, *inputs, **kwargs)
    204         config = kwargs.pop("config", None)
    205         if not isinstance(config, PretrainedConfig):
--> 206             config = AutoConfig.from_pretrained(pretrained_model_name_or_path, **kwargs)
    207 
    208         if "bert-base-japanese" in str(pretrained_model_name_or_path):

/usr/local/lib/python3.6/dist-packages/transformers/configuration_auto.py in from_pretrained(cls, pretrained_model_name_or_path, **kwargs)
    204 
    205         if "model_type" in config_dict:
--> 206             config_class = CONFIG_MAPPING[config_dict["model_type"]]
    207             return config_class.from_dict(config_dict, **kwargs)
    208         else:

KeyError: 'pegasus'
```<|||||>Yep, I've got this too.
![image](https://user-images.githubusercontent.com/17177967/90961867-b83c8e80-e4a3-11ea-8167-fe045b731c0c.png)
<|||||>@HenryDashwood , @Kejia  I can load both of these models on master branch.

What version of transformers are you using, try doing this with master as it's not available in 3.0.2 release.

`pip install -U git+https://github.com/huggingface/transformers.git`<|||||>Ah of course. Cheers!<|||||>@patil-suraj I tried installing the master version using the shared URL but still it wasn't updated to master version.
Can you share more details for installing Transformers Master version?<|||||>Sorry, typo. should be `-U` and not `-u`

`pip install -U git+https://github.com/huggingface/transformers.git`<|||||>I can't load the `PegasusTokenizer` for the checkpoint `google/pegasus-pubmed`:
```Python
tokenizer = PegasusTokenizer.from_pretrained("google/pegasus-pubmed")
```
Error:
```
Traceback (most recent call last):
  File "src/download_model.py", line 17, in <module>
    tokenizer = PegasusTokenizer.from_pretrained(config['model_name'])
  File "/home/rafael/miniconda3/envs/torch/lib/python3.8/site-packages/transformers/tokenization_utils_base.py", line 1584, in from_pretrained
    raise EnvironmentError(
OSError: Model name 'google/pegasus-pubmed' was not found in tokenizers model name list (google/pegasus-xsum). We assumed 'google/pegasus-pubmed' was a path, a model identifier, or url to a directory containing vocabulary files named ['spiece.model'] but couldn't find such vocabulary files at this path or url.
```

When using the `AutoTokenizer`:
```
tokenizer = AutoTokenizer.from_pretrained("google/pegasus-pubmed")
Traceback (most recent call last):
  File "/home/rafael/miniconda3/envs/torch/lib/python3.8/site-packages/transformers/configuration_utils.py", line 368, in get_config_dict
    resolved_config_file = cached_path(
  File "/home/rafael/miniconda3/envs/torch/lib/python3.8/site-packages/transformers/file_utils.py", line 957, in cached_path
    raise EnvironmentError("file {} not found".format(url_or_filename))
OSError: file google/pegasus-pubmed/config.json not found
```

ping @sshleifer 

I just installed it from master, still not working for me.

Environment Info:
- `transformers` version: 3.4.0
- Platform: Linux-5.4.0-51-generic-x86_64-with-glibc2.10
- Python version: 3.8.5
- PyTorch version (GPU?): 1.6.0 (True)
- Tensorflow version (GPU?): not installed (NA)
- Using GPU in script?: no
- Using distributed or parallel set-up in script?: no<|||||>Can't replicate on master. Please post `transformers-cli env` info when having download issues, and try solutions above in the thread before posting.<|||||>Ok I solved my issue. 
**FYI:** The problem was that I saved the loaded model in the directory `google/pegesus-pubmed` once in an invalid way and from now on the `from_pretrained` method tried to load it from the local path first which did not work. Sorry for bothering you!