## 事象
- [2021-07-30は成功](https://github.com/tadashi-aikawa/jumeaux/actions/runs/1080577848)
- [2021-07-31に失敗](https://github.com/tadashi-aikawa/jumeaux/actions/runs/1084003262)
### 失敗ログ
```
Installing collected packages: pycparser, urllib3, idna, charset-normalizer, cffi, certifi, zipp, requests, msgpack, jeepney, cryptography, webencodings, six, SecretStorage, pyparsing, pylev, ptyprocess, lockfile, importlib-resources, importlib-metadata, filelock, distlib, dataclasses, crashtest, cachecontrol, appdirs, virtualenv, tomlkit, shellingham, requests-toolbelt, poetry-core, pkginfo, pexpect, packaging, keyring, html5lib, entrypoints, cleo, cachy, poetry
Successfully installed SecretStorage-3.3.1 appdirs-1.4.4 cachecontrol-0.12.6 cachy-0.3.0 certifi-2021.5.30 cffi-1.14.6 charset-normalizer-2.0.4 cleo-1.0.0a4 crashtest-0.3.1 cryptography-3.4.7 dataclasses-0.8 distlib-0.3.2 entrypoints-0.3 filelock-3.0.12 html5lib-1.1 idna-3.2 importlib-metadata-1.7.0 importlib-resources-5.2.2 jeepney-0.7.1 keyring-22.3.0 lockfile-0.12.2 msgpack-1.0.2 packaging-20.9 pexpect-4.8.0 pkginfo-1.7.1 poetry-1.2.0a1 poetry-core-1.1.0a6 ptyprocess-0.7.0 pycparser-2.20 pylev-1.4.0 pyparsing-3.0.0b2 requests-2.26.0 requests-toolbelt-0.9.1 shellingham-1.4.0 six-1.16.0 tomlkit-0.7.2 urllib3-1.26.6 virtualenv-20.4.4 webencodings-0.5.1 zipp-3.5.0
Creating virtualenv jumeaux-9iSjC3Iy-py3.6 in /home/runner/.cache/pypoetry/virtualenvs
Installing dependencies from lock file
AttributeError
can't set attribute
at /opt/hostedtoolcache/Python/3.6.14/x64/lib/python3.6/site-packages/poetry/packages/dependency_package.py:38 in __setattr__
34│ def __setattr__(self, key: str, value: Any) -> None:
35│ if key in {"_dependency", "_package"}:
36│ return super().__setattr__(key, value)
37│
→ 38│ setattr(self._package, key, value)
39│
40│ def __str__(self) -> str:
41│ return str(self._package)
42│
```
## 原因
`poetry-core`が`1.1.0a6`にアップデートされたからぽい。
- [AttributeError: can't set attribute on "poetry install" · Issue #4334 · python-poetry/poetry](https://github.com/python-poetry/poetry/issues/4334)
直接原因は必要ないので調べていない。
## 対策
以下のいずれか。
### 安定版を使う
`--pre`フラグを外す。
```diff
- python -m pip install --upgrade pip poetry --pre
+ python -m pip install --upgrade pip poetry
```
### 不安定版のバージョンを下げる
`poetry-core`を`1.1.0a5`にする。
```shell
pip install poetry-core==1.1.0a5
```