This happens because poetry vendors dependencies in a really bad manner, and then inserts them onto the PYTHONPATH using the python version major.minor. I've been working on packaging the dependency tree properly... some things are now packaged, let me see if I can finally get this complete now!

...

I sort of don't like the idea of packaging beta releases for a semver major update just to get some vendored dependencies in the correct directory. Let's see if we can do better. ;)

```
$ pacman -Ql poetry | grep --color=never _vendor/py3 | awk '{print $2}' | awk -F'/' '{print $7}' | uniq
py3.4
py3.5
py3.6
py3.7
```

So, the PKGBUILD for poetry https://git.archlinux.org/svntogit/community.git/tree/trunk/PKGBUILD?h=packages/poetry

download the file https://github.com/sdispater/poetry/releases/download/0.12.17/poetry-0.12.17-linux.tar.gz

https://github.com/sdispater/poetry/releases/tag/0.12.17

and this file does not contains py3.8...

Here is a quickfix:
```
guillaume:~ 𝝿 sudo pacman -S poetry
...
guillaume:~ 𝝿 cd /usr/lib/poetry/poetry/_vendor/py3.7
guillaume:/usr/lib/poetry/poetry/_vendor/py3.7 𝝿 cd ..
guillaume:/usr/lib/poetry/poetry/_vendor 𝝿 sudo ln -s py3.7 py3.8
guillaume:/usr/lib/poetry/poetry/_vendor 𝝿
guillaume:/usr/lib/poetry/poetry/_vendor 𝝿 ls
py2.7 py3.4 py3.5 py3.6 py3.7 py3.8
guillaume:/usr/lib/poetry/poetry/_vendor 𝝿 poetry
Poetry 0.12.17

Usage:
command [options] [arguments]

...

```

I've just uploaded python-poetry 0.12.17-1 to community, which will replace 'poetry'. This completes a long-term goal I had agreed upon with svenstaro: the package now uses the same pkgname style as other python ecosystem tools like pip, and, relevant to this bug, it builds from source and uses system-packaged versions of its dependencies rather than vendoring a copy for every single python release other than the one archlinux actually provides. ;)

We're now also running the project unittests, and overall we should be much better able to cope with new versions of python and stuff. Try it out!

Basic testing didn't show any issues so far, thanks for the update.

Thanks a ton, Eli.