[TensorExpr] Add error checking in mem_arena

[jansel]

Gives an error message (rather than a segfault) if you forget KernelScope().

[facebook-github-bot]

💊 CI failures summary and remediations

As of commit eb43a32 (more details on the Dr. CI page):

---

✅ None of the CI failures appear to be your fault 💚

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• 1/1 tentatively recognized as flaky ❄️
  • Click here to rerun these jobs

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❄️ 1 failure tentatively classified as flaky

but reruns have not yet been triggered to confirm:

pytorch_windows_vs2019_py38_cuda11.1_build (1/1)

Step: "Build" (full log | diagnosis details | 🔁 rerun) ❄️

("Connection broken: ConnectionResetError(10054...ly closed by the remote host', None, 10054, None))

C:\Users\circleci\project>call C:\Jenkins\Miniconda3\Scripts\activate.bat C:\Jenkins\Miniconda3 

(base) C:\Users\circleci\project>if "" == "" (
call conda install -y -q python=3.8 numpy cffi pyyaml boto3  
 call conda install -y -q -c conda-forge cmake  
 call conda install -y -q -c conda-forge libuv=1.39 
) 
Collecting package metadata (current_repodata.json): ...working... done
Solving environment: ...working... done

("Connection broken: ConnectionResetError(10054, 'An existing connection was forcibly closed by the remote host', None, 10054, None)", ConnectionResetError(10054, 'An existing connection was forcibly closed by the remote host', None, 10054, None))


## Package Plan ##

  environment location: C:\Jenkins\Miniconda3

  added / updated specs:
    - boto3
    - cffi
    - numpy

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[facebook-github-bot]

@jansel has imported this pull request. If you are a Facebook employee, you can view this diff on Phabricator.

[bertmaher]

Good call!

[facebook-github-bot]

@jansel has imported this pull request. If you are a Facebook employee, you can view this diff on Phabricator.

[facebook-github-bot]

@jansel merged this pull request in ab70e1e.