Upgrading from 0.1.x to 0.2.x reports "Could not get unknown property 'me' for root project 'main'"

[centic9]

We use japicmp in Apache POI for comparing APIs across releases.

When I try to upgrade from 0.1.2 to 0.2.9, I always get "Could not get unknown property 'me' for root project 'main'"

I have now narrowed down the build-file to a very simple one which still shows this error, so I don't see anything that I could adjust in the build-files.

What am I missing here?

My reproducing project only has a single build.gradle with the following contents:

plugins {
    id 'me.champeau.gradle.japicmp' version '0.2.9'
}

apply plugin: 'java'

sourceCompatibility = 1.8
targetCompatibility = 1.8

task(japicmp, type: me.champeau.gradle.ArtifactJapicmpTask, dependsOn: jar) {
}

Stacktrace is

Caused by: groovy.lang.MissingPropertyException: Could not get unknown property 'me' for root project 'main' of type org.gradle.api.Project.
        at org.gradle.internal.metaobject.AbstractDynamicObject.getMissingProperty(AbstractDynamicObject.java:85)
        at org.gradle.groovy.scripts.BasicScript$ScriptDynamicObject.getMissingProperty(BasicScript.java:156)
        at org.gradle.internal.metaobject.AbstractDynamicObject.getProperty(AbstractDynamicObject.java:62)
        at org.gradle.groovy.scripts.BasicScript.getProperty(BasicScript.java:65)
        at build_d7kyjflcwiyjrkvon1xjy5su7.run(/tmp/test-japicmp/main/build.gradle:10)
        at org.gradle.groovy.scripts.internal.DefaultScriptRunnerFactory$ScriptRunnerImpl.run(DefaultScriptRunnerFactory.java:91)
        ... 119 more

Gradle version is 6.6.1