Auto plugins are required to declare their project configurations

[huntc]

Auto plugins are required to register any configurations that they may introduce in order to allow a user to declare any addition configurations of their own. For example, given some other configuration named Backend:

lazy val root = (project in file("."))
  .enablePlugins(JavaAppPackaging)
  .configs(Backend)

...a bundle:dist will subsequently fail as the plugin's configurations are effectively zapped.

Each new auto plugin that introduces a configuration should declare the configurations that it provides so that they may be prepended to declarations such as the one above. The method to override for each auto plugin is projectConfigurations. Here's an example from sbt-bundle (pending a PR):

  override def projectConfigurations: Seq[Configuration] =
    Seq(
      Bundle,
      BundleConfiguration
    )

[muuki88]

So for example our DockerPlugin should have an additional line

  object autoImport extends DockerKeys {
    val Docker = config("docker") extend Universal
  }
  import autoImport._

override def projectConfigurations: Seq[Configuration] = Docker :: Nil

Does this have any effect on existing behaviour?

[huntc]

I understand that adding it is benign.

[huntc]

I took a look at the sbt source and the auto plugin config sequence is prepended to any user supplied config via this override.

Perhaps @eed3si9n can confirm the effect of overriding the method as the right thing to do though.

[huntc]

Nice work!

[muuki88]

Thanks :)