Fix segmentation fault
Fix segmentation fault that started happening yesterday night.
Following the fix from #2205 that could be reproduced using circle ci ssh access.

~Currently fixing the unforeseen event with Python 2.~ The error with Python 2 was due to Regex releasing a new version (2019.12.17) that couldn't be built on Python 2.7.
# [Codecov](https://codecov.io/gh/huggingface/transformers/pull/2207?src=pr&el=h1) Report
> Merging [#2207](https://codecov.io/gh/huggingface/transformers/pull/2207?src=pr&el=desc) into [master](https://codecov.io/gh/huggingface/transformers/commit/f061606277322a013ec2d96509d3077e865ae875?src=pr&el=desc) will **increase** coverage by `1.13%`.
> The diff coverage is `83.33%`.

[![Impacted file tree graph](https://codecov.io/gh/huggingface/transformers/pull/2207/graphs/tree.svg?width=650&token=9qOlN6Hb1c&height=150&src=pr)](https://codecov.io/gh/huggingface/transformers/pull/2207?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master    #2207      +/-   ##
==========================================
+ Coverage   80.32%   81.46%   +1.13%     
==========================================
  Files         122      122              
  Lines       18342    18345       +3     
==========================================
+ Hits        14734    14945     +211     
+ Misses       3608     3400     -208
```


| [Impacted Files](https://codecov.io/gh/huggingface/transformers/pull/2207?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [transformers/file\_utils.py](https://codecov.io/gh/huggingface/transformers/pull/2207/diff?src=pr&el=tree#diff-dHJhbnNmb3JtZXJzL2ZpbGVfdXRpbHMucHk=) | `70.42% <83.33%> (-1.01%)` | :arrow_down: |
| [transformers/modeling\_openai.py](https://codecov.io/gh/huggingface/transformers/pull/2207/diff?src=pr&el=tree#diff-dHJhbnNmb3JtZXJzL21vZGVsaW5nX29wZW5haS5weQ==) | `81.51% <0%> (+1.32%)` | :arrow_up: |
| [transformers/modeling\_ctrl.py](https://codecov.io/gh/huggingface/transformers/pull/2207/diff?src=pr&el=tree#diff-dHJhbnNmb3JtZXJzL21vZGVsaW5nX2N0cmwucHk=) | `96.47% <0%> (+2.2%)` | :arrow_up: |
| [transformers/modeling\_xlnet.py](https://codecov.io/gh/huggingface/transformers/pull/2207/diff?src=pr&el=tree#diff-dHJhbnNmb3JtZXJzL21vZGVsaW5nX3hsbmV0LnB5) | `74.54% <0%> (+2.32%)` | :arrow_up: |
| [transformers/modeling\_roberta.py](https://codecov.io/gh/huggingface/transformers/pull/2207/diff?src=pr&el=tree#diff-dHJhbnNmb3JtZXJzL21vZGVsaW5nX3JvYmVydGEucHk=) | `71.76% <0%> (+12.35%)` | :arrow_up: |
| [transformers/tests/modeling\_tf\_common\_test.py](https://codecov.io/gh/huggingface/transformers/pull/2207/diff?src=pr&el=tree#diff-dHJhbnNmb3JtZXJzL3Rlc3RzL21vZGVsaW5nX3RmX2NvbW1vbl90ZXN0LnB5) | `97.41% <0%> (+17.24%)` | :arrow_up: |
| [transformers/modeling\_tf\_pytorch\_utils.py](https://codecov.io/gh/huggingface/transformers/pull/2207/diff?src=pr&el=tree#diff-dHJhbnNmb3JtZXJzL21vZGVsaW5nX3RmX3B5dG9yY2hfdXRpbHMucHk=) | `92.15% <0%> (+83%)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/huggingface/transformers/pull/2207?src=pr&el=continue).
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> Powered by [Codecov](https://codecov.io/gh/huggingface/transformers/pull/2207?src=pr&el=footer). Last update [f061606...14cc752](https://codecov.io/gh/huggingface/transformers/pull/2207?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
<|||||>is this issue related to https://github.com/scipy/scipy/issues/11237, which also started happening yesterday.<|||||>Indeed, this is related to that issue. I've just tested on the CircleCI machine directly, the segmentation fault happens when importing torch after tensorflow, when scipy is installed on the machine.<|||||>@LysandreJik I get this error on transfomers 2.2.2 on PyPi. When it will be updated?

```
>>> import transformers
Segmentation fault (core dumped)
```

```
root@261246f307ae:~/src# python --version
Python 3.6.8
```<|||||>This is due to an upstream issue related to scipy 1.4.0.  Please pin your scipy version to one earlier than 1.4.0 and you should see this segmentation fault resolved.<|||||>@LysandreJik thank you this issue is destroying everything 🗡 <|||||>Did pinning the scipy version fix your issue?<|||||>@LysandreJik I'm now pinning `scipy==1.3.3` that is the latest version before RC1.4.x<|||||>I confirm that with 1.3.3 works, but they have just now pushed `scipy==1.4.1`.  We have tested it and it works as well.

 - https://github.com/scipy/scipy/issues/11237#issuecomment-567550894
Thank you!<|||||>Glad you could make it work!