How to GPG sign and publish an aar directly to Maven Central?

Question

I'm working on properly setting up my Gradle scripts for publishing an .aar directly to Maven Central (with JFrog sunsetting Bintray , numerous resources about publishing to Bintray are no longer relevant). One of the prerequisites is to have all artifacts (aar, sources jar, java-doc jar, pom.xml) uploaded alongside corresponding GPG-signature files (eg sources.jar.asc ).

Following these two guides (which are very much alike), I've largely managed to do so:

• https://medium.com/@nmauti/sign-and-publish-on-maven-central-a-project-with-the-new-maven-publish-gradle-plugin-22a72a4bfd4b
• https://www.albertgao.xyz/2018/01/18/how-to-publish-artifact-to-maven-central-via-gradle/

However, though well describing the solution using Gradle, both guides seem to focus on plain.jar's rather than.aar's. In particular, I wasn't sure about what to set up as a project archive in order to put on the automated sign+publish list, as suggested:

project.artifacts {
    archives sourceJar // Ok, I have a sourceJar task - will be signed and uploaded
    archives javadocJar // I use Dokka, but got that to work by registering my dokka task
    archives jar // What's "jar"? this doesn't help much!... :-/
}

I even tried registering the output .aar file, explicitly:

publications {
    android.libraryVariants.all { variant ->
        if (shouldPublishVariant(variant)) {
          // ...
          // ...

          variant.outputs.forEach { output ->
              project.artifacts {
                  archives output.outputFile // The full path of the .aar to publish!
              }
          }
        }
    }
}

But that seemed to have resulted in this flaky error:

Execution failed for task ':detox:publishMavenFullReleaseAarPublicationToMavenRepository'.
> Failed to publish publication 'mavenFullReleaseAar' to repository 'maven'
   > Invalid publication 'mavenFullReleaseAar': artifact file does not exist: '.../build/outputs/aar/library-full-release.aar.asc'

I'm looking for a stable, bullet-proof solution that would sort this out end-to-end, with no flaky errors.

Answer 1

As a solution, I've found that registering the task generating the .aar as a project archive -- rather than registering the file itself, does the trick (much like as done for the sources and javadoc jars):

publications {
    android.libraryVariants.all { variant ->
        if (shouldPublishVariant(variant)) {
          // ...
          // ...

          variant.outputs.forEach { output ->
              project.artifacts {
                  // For example: bundleProdReleaseAar is the task that generates library-prod-release.aar
                  archives project.tasks["bundle${variant.name.capitalize()}Aar"]
              }
          }
        }
    }
}