JaCoCo reports not working

[alvarosanchez]

At some point (perhaps with a Gradle update?) the JaCoCo reports stopped working. For example:

https://github.com/micronaut-projects/micronaut-openapi/actions/runs/5329318280/jobs/9654878870?pr=1059

No coverage report can be found with sonar.coverage.jacoco.xmlReportPaths='/home/runner/work/micronaut-openapi/micronaut-openapi/build/reports/jacoco/testCodeCoverageReport/testCodeCoverageReport.xml'. Using default locations: target/site/jacoco/jacoco.xml,target/site/jacoco-it/jacoco.xml,build/reports/jacoco/test/jacocoTestReport.xml

The aggregator project certainly doesn't contain the report. But neither the individual projects. If I try to run jacocoTestReport directly, I get:

Exception in thread "OkHttp TaskRunner" java.lang.NoClassDefFoundError: kotlin/jvm/internal/Ref$IntRef
        at okhttp3.internal.http2.Http2Connection.shutdown(Http2Connection.kt:419)
        at okhttp3.internal.http2.Http2Connection.close$okhttp(Http2Connection.kt:449)
        at okhttp3.internal.http2.Http2Connection$ReaderRunnable.invoke(Http2Connection.kt:627)
        at okhttp3.internal.http2.Http2Connection$ReaderRunnable.invoke(Http2Connection.kt:609)
        at okhttp3.internal.concurrent.TaskQueue$execute$1.runOnce(TaskQueue.kt:98)
        at okhttp3.internal.concurrent.TaskRunner.runTask(TaskRunner.kt:116)
        at okhttp3.internal.concurrent.TaskRunner.access$runTask(TaskRunner.kt:42)
        at okhttp3.internal.concurrent.TaskRunner$runnable$1.run(TaskRunner.kt:65)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
        at java.base/java.lang.Thread.run(Thread.java:833)
Caused by: java.lang.ClassNotFoundException: kotlin.jvm.internal.Ref$IntRef
        ... 11 more

Build is successful, but no report is created.