How to spring-boot 2.4.0 and kotlin 1.4.20

Question

I am trying to build a spring-boot Microservice. The build is using releasee 2.4.0 of spring-boot. I am trying to compile this build with the new release 1.4.20 of kotlin.

How can I build this without failures? Try to create a kotlin Microservice with start.spring.io . Edit the pom to use the newest kotlin release...

When building:

Execution compile of goal org.jetbrains.kotlin:kotlin-maven-plugin:1.4.20:compile failed: A required class was missing while executing org.jetbrains.kotlin:kotlin-maven-plugin:1.4.20:compile: kotlin/reflect/KDeclarationContainer
...

If you choose kotlin as main language (as one should) and picks java 15, one get the following error:

Compilation failure
[ERROR] Unknown JVM target version: 15
[ERROR] Supported versions: 1.6, 1.8, 9, 10, 11, 12, 13, 14

There is something fundamentally wrong with the spring-boot configuration provided from start.spring.io as the target of the new kotlin version 1.4.20 is java 15: what's new in kotlin 1.4.20

Answer 1

The error seemed to be a bug only visible on Mac OS Big Sur (intel version), but was solved by updating to kotlin release 1.4.21

Answer 2

updating kotlin version works for me.