Well, this is weird. I just started getting a KotlinReflectionNotSupportedError exception on both IDEA 15 and 2016.1 when I try to run lein tasks.

And kotlin-reflect.jar is on both applications.

OK, known issue.

@ricardo: yeah, I thought this was a new issue in v2016.1 because people started reporting it right after the release, but it looks like it predates that.

Anyway, it’s fixed now.

@cfleming: I’m curious, what was the cause? I didn’t get it right after upgrading, but only until today, and it then showed up on both 15 and 2016.1, which had me thinking was an environment issue.

@ricardo: It’s weird, I can’t see why people wouldn’t have got this earlier.

This is using Kotlin:

val logger: Logger = Logger.getInstance(LeiningenCommandLineState::class.simpleName)

The trick there is that LeiningenCommandLineState::class returns a Kotlin class, not the Java class (I don’t fully understand the difference), and calling simpleName on the Kotlin one apparently requires the reflection classes.

Changing it to:

val logger: Logger = Logger.getInstance(LeiningenCommandLineState::class.java.simpleName)

returns the actual Java class, which works fine.

The only thing I can think of is that the latest plugin bundles a later version of Kotlin, and that behaviour has changed in Kotlin.

Interesting, thanks.