Bug report to Kotlin devs for this issue.
- Make sure your
JAVA_HOME
points to a JDK7 gradlew clean build
- Rename the
build
directory tobuildjdk7
- Switch your
JAVA_HOME
to a JDK8 - Compare the .class files in
build/classes
andbuildjdk7/classes
with your favorite decompiler
build/classes/KotlinTest.class
should have a variable typed ConcurrentHashMap.KeySetView
, but not build/classes/JavaTest.class