Issue
You are receiving errors or build failures from a buildpack developed and maintained by an entity other than Heroku.
Resolution
If the buildpack is hosted in the Buildpack Registry, the author may have provided a support URL. You can view this URL by running a command like:
$ heroku buildpacks:info jkutner/minecraft
=== jkutner/minecraft
description: A buildpack for running a Minecraft server on Heroku
category: tools
license: MIT License
support: https://github.com/jkutner/heroku-buildpack-minecraft/issues
In this example the support URL is https://github.com/jkutner/heroku-buildpack-minecraft/issues.
When running the heroku buildpacks:info -a jkutner/minecraft command Replace jkutner/minecraft with the namespace and name of the buildpack you are trying to use. The command may display either a support URL or an email address - please note however that some buildpacks may no longer be supported by the original maintainers.
Heroku Support are not able to assist with any issues related to buildpacks that are not included on the officially supported buildpacks list.
If you are using a Github URL when adding the buildpack, instead of a buildpack from the registry, you can open a Github Issue on the repository's web page.