Memory consumption using "kill switch"

While building JUnit 5 on Travis CI using jdk-9-b168 on branch [1] I used the "kill switch" to allow Gradle/Groovy perform their work with illegal accesses allowed. The build failed due to an OutOfMemoryException. See [2] for the logs.

When I replace the "kill switch" with "--add-opens" options, the build runs. See [3] or current master [4] for details.

Is the logging copied from [2] produced by --permit-illegal-access a memory devourer?

WARNING: --permit-illegal-access will be removed in the next major release

WARNING: Illegal access by worker.org.gradle.internal.reflect.JavaMethod (file:/home/travis/.gradle/caches/3.5/workerMain/gradle-worker.jar) to method java.lang.ClassLoader.getPackages() (permitted by --permit-illegal-access)

WARNING: Illegal access by org.codehaus.groovy.reflection.CachedClass (file:/home/travis/.gradle/wrapper/dists/gradle-3.5-bin/daoimhu7k5rlo48ntmxw2ok3e/gradle-3.5/lib/groovy-all-2.4.10.jar) to method java.lang.Object.finalize() (permitted by --permit-illegal-access)

[...]

Cheers,

Christian

[1] https://github.com/junit-team/junit5/pull/842/commits

[2] https://travis-ci.org/junit-team/junit5/jobs/232398716#L947

[3] https://travis-ci.org/junit-team/junit5/jobs/232406998

[4] https://github.com/junit-team/junit5