If I try to run the `strikt` package in `strikt-co...

# failgood

[robfletcher]

If I try to run the strikt package in strikt-core I get this error

Internal Error occurred.
org.junit.platform.commons.JUnitException: TestEngine with ID 'failfast' failed to discover tests
	at org.junit.platform.launcher.core.EngineDiscoveryOrchestrator.discoverEngineRoot(EngineDiscoveryOrchestrator.java:111)
	at org.junit.platform.launcher.core.EngineDiscoveryOrchestrator.discover(EngineDiscoveryOrchestrator.java:85)
	at org.junit.platform.launcher.core.DefaultLauncher.discover(DefaultLauncher.java:92)
	at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:75)
	at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:71)
	at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
	at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:221)
	at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:54)
Caused by: failfast.FailFastException: unknown selector in discovery request: org.junit.platform.launcher.core.DefaultDiscoveryRequest@491cc5c9
	at failfast.junit.FailFastJunitTestEngine.findContexts(FailFastJunitTestEngine.kt:196)
	at failfast.junit.FailFastJunitTestEngine.discover(FailFastJunitTestEngine.kt:36)
	at org.junit.platform.launcher.core.EngineDiscoveryOrchestrator.discoverEngineRoot(EngineDiscoveryOrchestrator.java:103)
	... 7 more