Kotlin no longer compiled with JVM 1.8 target


It seems Kotlin is now compiled on codingame with JVM 1.6 target instead of JVM 1.8, probably since the last Kotlin 1.3 update.

Code that was working last summer using java 8 features (Comparator.comparingInt(…)) no longer compiles on codingame, and the error message indicates that a JVM 1.6 target is used :

error: calls to static methods in Java interfaces are prohibited in JVM target 1.6. Recompile with ‘-jvm-target 1.8’.


Hi @kgautron,

Ok we’ll try. Do you know if this kotlinc jvm-target option (and potentially others) is documented somewhere?



Hi @_CG_XorMode,

I could not find any kotlinc documentation either (I usually let my IDE compile for me).

But by looking at the following classes from kotlin git repo, i would guess that the option to pass is : ‘jvmTarget’, and the value to use (for JDK 8) : ‘1.8’.


Also there must be someone in the team who has already done it, because i remember a post on the forum about going from jvm 1.5 to jvm 1.8 for kotlin.

Good luck :wink:


Fixed! See https://www.codingame.com/forum/t/languages-update/1574/98