KSP task (non-)registration happens too soon

[ZacSweers]

I have a gradle plugin that tries to conditionally enable KSP and add relevant KSP processors to it. However, I found that KSP's task registration can be unintentionally deleted by a simple project.afterEvaluate in gradle, resulting in the task never being registered and thus not run.

Example

// in build.gradle.kts, or a gradle plugin

project.afterEvaluate {
  if (enableKsp) {
    pluginManager.apply("com.google.devtools.ksp")

    dependencies.add("ksp", "some.ksp:processor:1.0.0")
  }
}

will result in KSP being applied but no ksp*Kotlin task ever being registered and thus never running. If I add any dependency to the ksp configuration (even one without any KSP processors in it), it works and picks up the later-added dependency too.

I think I would expect this to always register the KSP task, then conditionally no-op at task-action-time rather than try to conditionally avoid adding the task.

[ZacSweers]

Sorry it looks like this is actually after two afterEvaluate calls, not just one level. Which is admittedly a somewhat edge case :). That said, still would be nice if there was a way to defer this to task-time instead