Hi!

Poetry support has just been added to the Heroku Python buildpack:

• https://devcenter.heroku.com/changelog-items/3050
• Add support for Poetry heroku/heroku-buildpack-python#1682

This means using a separate buildpack (such as this one) is no longer required.

Switching from this buildpack to the built-in Python buildpack Poetry support also means that dependencies will be installed by Poetry directly, rather than the poetry.lock file first being exported to requirements.txt and then being installed by pip - which should result in faster builds that more closely match your local development environments.

To switch over, you will need to remove this buildpack from your app configuration, since otherwise the requirements.txt file generated by this buildpack will take precedence over poetry.lock. (I implemented it this way for now to ensure backwards compatibility and to allow people to migrate their apps in their own time. Though in the future the presence of multiple package manager files will be made an error to improve the UX in the case where users have accidentally ended up with several files in their repo - something that results in support tickets from time to time.)

In order to raise awareness of the built-in Python buildpacks support, it would be great if this buildpack could emit a message during the build. Also, given #74 IMO it makes sense to call this a deprecation. (I'll open a PR for this now.)