aQute | Snippets that show the use of OSGi and bndtools | Application Framework library

Looks like you're creating an extension function on KotlinBuildScript which may or may not be the issue. Regardless, there's no need for extension functions since you can just use the DSL directly.

Gradle calls the shared build logic convention plugins: https://docs.gradle.org/current/samples/sample_convention_plugins.html#compiling_convention_plugins

So your Example.kt would become kotlin-conventions.gradle.kts:

No, you cannot use properties from dependencies.

If you need common properties, you can define them in a parent POM that is used by the different projects (this does not require them to be modules)

Ended up solving the issue with help from https://groups.google.com/forum/#!forum/bndtools-users having found two (three?) problems with my configuration.

The correct form for repository definition in build.bnd seems to be

I vaguely remember running into the same issue. If I am not mistaken, version 12 of the AEM Archetype had this issue. I believe it was fixed in version 13, although you may want to try the latest version (19) from the aem-project-archetype repository

Bamboo doesn't work with Java 11 yet. So plugin should be built with Java 8 as well

Without disecting the error message Caused by: java.lang.IllegalArgumentException: wrong number of arguments:

The way you build your plugin (Ant, Maven, Gradle, manually) doesn't make a difference, as long as you build a plugin that will be understood by the runtime. aQute.bnd.annotation.metatype.Meta points firmly into the OSGi world, and makes it almost certain that you'll need an OSGi module. You can build this with Ant, of course. Even in Ant you can embed tools like bnd, or you can write the proper Manifest.mf to include in your module manually (just kidding - you don't want to do it manually, but it would work).

Recommendation: Instead of moving everything over: Try to reproduce this with a minimal example in gradle or better Liferay Workspace (which is gradle based), just to get all the automatic wiring in. Check if it makes a difference and compare the generated output from your Ant build process with the workspace output. Pay specific attention to the Manifest.

In order to build the proper Manifest, you want to use bnd - if the Manifest turns out to be your issue: Find a way to embrace bnd - if that's by saying goodby to Ant, or by tweaking your build script remains your decision.

Currently the best practice for logging in OSGi is to use slf4j as front end.

It is unclear if bnd_version is defined in this line:

The answer is in the stack trace. It is missing classes: Caused by: java.lang.NoClassDefFoundError: com/google/gson/Gson. Usually, Gson should be part of AEM out-of-the-box. Check if it is there and export/import of the classes works.

Thank You Jens