Recent bump to 3.7.4.2 fails projects that depend on typing

[vkuzmin-uber]

After recent bump https://github.com/python/typing/blob/master/setup.py we started to see problem:

"ERROR: You need Python 2.7 or 3.4 to install the typing package."

It introduces problem for projects that used py 2.7 and 3.7 if it used "typing" w/o pinned version

[jviebach]

I'm seeing same error message when installing a package (couchbase-python-sdk) that includes 'typing' in requirements.txt on Py 3.6.10 (AWS Linux/Elastic Beanstalk). Just started after 3.7.4.2 release.

[gvanrossum]

Does pinning typing to 3.7.4.1 work?

[vkuzmin-uber]

Yes, as workaround.

I use project Neuropod, that has setup script:

https://github.com/uber/neuropod/blob/master/source/python/setup.py

so, now I need to do the following:

# pin typing version that works with all python versions.
pip install typing=="3.7.4.1"
python .neuropod/source/python/setup.py install

but still, if some version of product is "released', this is broken really. Frankly, I guess we need typing 3.7.4.3 that fixes the issue.

[jviebach]

I was also able to pin to 3.7.4.1 to allow containing package to load-- but doing so in Elastic Beanstalk is cumbersome to say the least. Most pip packages load via a requirements.txt file, but since I can't override order of install from a requirements.txt file, I had to create an .ebextension file to install typing before requirements.txt.

`
commands:

07-command:

    command: /opt/python/run/venv/bin/pip install typing==3.7.4.1`

[gvanrossum]

Why can’t you edit the requirements.txt file to pin the version? (Or for that matter to require typing only for Python 3.4?)

[vkuzmin-uber]

I can do it for "master" and release a new version of my lib/package. But there are already "released" versions with their dependencies to "typing" w/o pinned version.

It means users of the libraries and packages that has dependencies on "typing", need to upgrade now. And some users just can't upgrade to latest, if they use 2.0 and don't want 3.0 or 3.1 need to produce for them packages with "minor" fix 2.1 now.

[gvanrossum]

Okay okay I will see what I can do next week. It seems no good deed goes unpunished. :-)

[gvanrossum]

I have a request though. Can you test that the new version of typing actually works with your app apart from the version checks in setup.py? You should be able to test this by cloning the repo and reverting these two diffs:

• c850161 (HEAD -> master, tag: 3.7.4.2, origin/master, origin/HEAD) Bump version to 3.7.4.2
• 0b0e248 Disallow installation on 3.5+

If that doesn't work we'd just be doing the same dance next week.

Same for others who piled on this issue.

[vkuzmin-uber]

I cannot help much with test. I am not using package in my project. I use Neuropod that uses "typing" for tests as I understand:

https://github.com/uber/neuropod/blob/master/source/python/setup.py

I even uninstall it after "setup" from virtual environment to have no extra dependencies (I don't run tests fo Neuropod in my project and so don't need this dependency).

[gvanrossum]

Well, you claimed to have a workaround that pins the version of typing. Can't you modify that workaround to instead pin a version in a forked version of typing that has the changes I suggested? I don't have access to AWS so I am flying blind here.

[vkuzmin-uber]

I can confirm that in my case it works, I used this command to pin it:

pip install git+https://github.com/python/typing.git@520d31b0c5616e12b56c05079d86dae5fba3aff0

[gvanrossum]

Okay, there's now a 3.7.4.3 that's the same as 3.7.4.2 except for the setup.py changes. Can you give it a spin before I close this issue?

https://pypi.org/project/typing/3.7.4.3/ (give PyPI a few minutes to update its cache)

[jviebach]

It works now for me without work around. Thank you.
Specifics:
Python 3.6.10 installing package 'couchbase-python-client==2.5.12' that includes 'typing' (no pin) as a requirement. Tests pass.