What could be the reason for getting an `Unsupported class file major version 64` message when I try...

# compiler

[Tóth István Zoltán]

What could be the reason for getting an Unsupported class file major version 64 message when I try to debug a plugin test built on AbstractKotlinCompilerTest ? Non-debug run works well, but when I try to debug I get this error.
Compiler: 1.9.0
Gradle 8.0

Error text:

FAILURE: Build failed with an exception.
* What went wrong:
Could not open cp_init generic class cache for initialization script '/private/var/folders/11/63l49c192nnbxhmjpxggc2640000gn/T/ijresolvers2.gradle' (/Users/tiz/.gradle/caches/8.0/scripts/7hfc6zkep672kceu7v66gggt9).
> BUG! exception in phase 'semantic analysis' in source unit '_BuildScript_' Unsupported class file major version 64

[hfhbd]

Java class Version 64 is Java 20, which isn’t supported by Gradle 8.2

[Tóth István Zoltán]

Oh, my! One of the projects haven't had the Java version set down, my bad.

[chanjungskim]

Is the default 20?

[chanjungskim]

I am using gradle 8.0.2 + K2

[Tóth István Zoltán]

I don't think 20 is the default in general. I have it installed, I guess it took the latest.