Tests fail locally on Windows

[pkch]

Locally, I am getting:

FAILURE #17 check stubs

typeshed\stdlib\3\ntpath.pyi:1: error: Name 'posixpath' is not defined
typeshed\stdlib\3\macpath.pyi:1: error: Name 'posixpath' is not defined

The entire contents of each of those files is just posixpath.pyi.

But somehow everything passes on CI.

[gvanrossum]

Check the recent PR that fixes symlinks. There is a git setting.

[gvanrossum]

In particular #3213.

We need to add instructions for developers on Windows to README.md. Once those are there (and you've got it working for yourself) we can close this.

[pkch]

So far my experience is that it works as long as the user has permissions for creating symlinks.

Theoretically, the permissions should be already enabled for anyone with the current version of Windows 10 running in developer mode. In practice, it only worked for me when I ran git clone from the Administrator command prompt. (I followed instructions from here and it didn't help.)

I'll let someone else test this out before closing this issue.

[gvanrossum]

Heh. I had no idea that Windows even supported symlinks at all. I have no idea what I was thinking the fix did (I think I believed it made git interpret the symlinks itself. :-) Neat.

I have no way to test this myself so I'll keep it open.

[pkch]

To whoever plans to test it more:

It seems there's a glitch with Microsoft implementation of permissions which means that if you are a member of an Administrator group, you will not be able to use symlinks from a regular command prompt, even if you've followed all the instructions (such as setting the right group policy or enabling Developer mode in Windows 10).

These workaround have been proposed:

1. remove yourself from the Administrator group
2. run all git commands as a non-Adminstrator user (using runas)
3. use Adminstrator (elevated) instead of a regular command prompt (yes, it's counter-intuitive)

I only tested option (3), and it worked for me.

I have been unable to convert an existing repo to a repo with symlinks; I had to make a new one. Before deleting / overwriting the old repo, make sure you are ok with losing:

• unreachable commits (and reflog history itself)
• unpushed commits in branches
• uncommited changes in the working directory, including untracked or ignored file
• probably some other stuff like local-only tags, etc.

[JelleZijlstra]

Thanks for looking into this. Since the symlinks are only in the typeshed submodule, do you really have to fully delete your old repo? I think you should be able to just rm -rf typeshed/ and then again git submodule init/git submodule update.

[pkch]

I thought we also have one in mypy:

./test-data/.flake8@ -> ../typeshed/.flake8

It's less important than the others. If we remove it, and make sure to never add symlinks to mypy itself, what you said should work.

It's only worth it if we think future contributors will first clone the repo without RTFM, and only then start looking things up when they notice tests don't work :)

[gvanrossum]

Yeah, let's remove the one symbolic link in the mypy repo itself.

[pkch]

In addition, I found that to switch between commits (using git checkout) that have any difference in symlinks (e.g., one is added or deleted), one needs to be using Administrator command prompt on Windows (or else Git gets confused and git checkout deletes the file instead of updating the symlink -- at least on my version of Windows 10).

Not a problem, as long as it's documented.

[gvanrossum]

This worries me a bit.

I wonder if a solution that requires one to do many crucial Git manipulations as Administrator isn't too brittle. Maybe we need to reopen python/typeshed#1175 ?

[JukkaL]

I'm also worried about this. Let's reconsider the use of symlinks on Windows?

…

On Sun, Apr 30, 2017 at 05:03 Guido van Rossum ***@***.***> wrote: This worries me a bit. I wonder if a solution that requires one to do many crucial Git manipulations as Administrator isn't too brittle. Maybe we need to reopen python/typeshed#1175 <python/typeshed#1175> ? — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#3222 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABDnx6ZFaRA3H4qosPaw2hqLsoNgDxJHks5r1AgQgaJpZM4NFIgV> .