Python 3.7 stopped working

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26 Feb, 2019 11:58 AM

It seems Python 3.7 builds are failing (they never failed before):

The other Python verions (3.5 and 3.6) are working as expected:

Source code:

  1. Support Staff 1 Posted by Owen McDonnell on 27 Feb, 2019 01:04 AM

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    Python was updated in latest platform update. What version are you using locally to build successfully?

  2. 2 Posted by osbrain-ci on 27 Feb, 2019 08:52 AM

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    I am using Python 3.7.2 locally, which I think is the latest Python 3.7 version.

  3. Support Staff 3 Posted by Owen McDonnell on 27 Feb, 2019 11:06 PM

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    I don't know too much about tox, but i installed latest python (3.7.2) on my local dev machine (windows) and tried to run your build script and ran into the same error as on the build VMs.
    Are there any other special steps i should take to make it build locally?

  4. 4 Posted by osbrain-ci on 27 Feb, 2019 11:59 PM

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    Not reallly. Can you confirm you can run `tox -e py36` or `tox -e py35` but not `tox -e py37`?

    I am assuming you do have Python 3.7 available in your system, and that it is installed under C:\\Python37-x64, as it (should be?) installed in AppVeyor. At least that is what I have configured in the `.appveyor.yml` file, and used to work fine up until now..

  5. Support Staff 5 Posted by Owen McDonnell on 28 Feb, 2019 01:16 AM

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    Yes i can confirm that. I also rolled back to python 3.7.0 and your exact command worked (tox -e py -- -n 2 --color=yes).
    See attached screenshots.

  6. 6 Posted by osbrain-ci on 28 Feb, 2019 10:49 PM

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    I opened this issue in Tox's repository:

    Apparently, it cannot be reproduced in Azure pipelines either.

    As I mention in that issue, I tried downgrading Tox (3.5.0) and virtualenv (16.1.0) and retriggered AppVeyor pipelines, but they failed again:

    Do you think there is no way it could be an AppVeyor problem? Maybe not, but I am not sure who to report this issue at this point. :-/

  7. Support Staff 7 Posted by Owen McDonnell on 01 Mar, 2019 05:24 PM

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    I did some more testing locally and was able to make this command run if i skipped production of a virtualenv.
    Again, I don't have much experience with python development (especially tox testing) but it seems that tox creates its own virtualenv and so there is some confusion between which python.exe to use?

    Here is a build of your repo with the same approach which succeeds.

  8. 8 Posted by osbrain-ci on 04 Mar, 2019 09:05 AM

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    Thanks Owen for having a look at it.

    Why do you think Tox would only get confused with Python 3.7 and not 3.5 or 3.6? Is it possible that AppVeyor's Python 3.7 is installed differently somehow? Or a path be missing somewhere?

    I ask because Tox is able to successfully run those pipelines with all Python versions in Azure Pipelines, Travis and locally, so it maybe is an AppVeyor-only problem.

  9. Support Staff 9 Posted by Owen McDonnell on 04 Mar, 2019 05:28 PM

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    Well as i demonstrated earlier, it's not an AppVeyor-only problem since it's on my local machine as well.
    Feel free to ask me any questions about my local machine, if you'd like to figure out the differences between it and your local machine.

    On travis, you're building on linux I assume?... not really comparable.

    What do you make of skipping virtualenv production leading to a successful build? Does tox not create its own virtualenv?

  10. 10 Posted by osbrain-ci on 04 Mar, 2019 05:48 PM

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    Hi Owen,

    You are right, that works perfectly:

    It seems I was missing `%PYTHON%\Scripts` in the `PATH`, which you had in your builds. I did not see that the first time I had a look at them.

    Thanks for your help and for your patience.

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