Extras of a dependency's dependency are not installed

• I am on the latest Poetry version.
• I have searched the issues of this repo and believe that this is not a duplicate.
• If an exception occurs when executing a command, I executed it again in debug mode (-vvv option).

• OS version and name: Ubuntu 18.04
• Poetry version: 0.12.17 and 1.0.0b5
• Link of a Gist with the contents of your pyproject.toml file: https://github.com/hukkinj1/bug-poetry-dependency-extras/blob/master/pyproject.toml

Issue

Poetry does not install extras of a dependency’s dependency, if the dependency’s dependency is also referenced without the extra.

Here’s the pyproject.toml. The generated poetry.lock lockfile is here.

Pyproject.toml requires PyOTA package, which requires requests[security]. The security extra is not installed though. This can be observed by the fact the the lockfile has no pyOpenSSL entry, which is a part of the security extra of requests.

Note that we remove requests = "*" from pyproject.toml, then the security extra will be installed as expected. It seems the issue only occurs when the package that needs extras is referenced elsewhere with no mention of the extras.

[mvoitko]

@abn updating helped

[sdispater]

The only way we can solve the extras issues currently is by always resolving the extra dependencies even though they were not opted in. That would fix the issue but it might introduce another which is that resolution conflict might be raised by extra dependencies even though they were never opted in.

I don’t see a perfect solution for this at the moment. The Python ecosystem is so unique and complex (some might say convoluted) that coming up with a perfect dependency resolver is almost impossible and will sometimes require the help of the end user by hinting it on how it should proceed.