I actually removed everything I could from the project. The only dependency I have is to kotlintest. I have one spec with one test and still:

mypackage.MyTest > should return the length of the string FAILED
    org.opentest4j.AssertionFailedError at MyTest.kt:10

mypackage.MyTest > mypackage.MyTest > executionError FAILED
    org.opentest4j.AssertionFailedError at MyTest.kt:10