Gradlew check fails to run

[miakizz]

Describe the bug
In attempting to troubleshoot #660, I tried to get a dev environment running, but failed due to (I suspect) my version of Java being too new. I tried to compile with an older version, but I'm not super familiar with gradle so didn't get very far.

To Reproduce
Steps to reproduce the behaviour:

1. Clone project
2. Run gradlew check

Expected behaviour
Checks pass

Stack trace / error log

Kotlin does not yet support 25 JDK target, falling back to Kotlin JVM_24 JVM target
Kotlin does not yet support 25 JDK target, falling back to Kotlin JVM_24 JVM target
> Task :sample-kotlin:detekt FAILED
> Task :bigbone-rx:detekt FAILED

[Incubating] Problems report is available at: file:///Users/miakizz/coding/bigbone/build/reports/problems/problems-report.html

FAILURE: Build completed with 2 failures.

1: Task failed with an exception.
-----------
* What went wrong:
Execution failed for task ':sample-kotlin:detekt'.
> Invalid value (25) passed to --jvm-target, must be one of [1.6, 1.8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22]

* Try:
> Run with --stacktrace option to get the stack trace.
> Run with --info or --debug option to get more log output.
> Run with --scan to generate a Build Scan (powered by Develocity).
> Get more help at https://help.gradle.org.
==============================================================================

2: Task failed with an exception.
-----------
* What went wrong:
Execution failed for task ':bigbone-rx:detekt'.
> 25.0.2

* Try:
> Run with --stacktrace option to get the stack trace.
> Run with --info or --debug option to get more log output.
> Run with --scan to generate a Build Scan (powered by Develocity).
> Get more help at https://help.gradle.org.
==============================================================================

Deprecated Gradle features were used in this build, making it incompatible with Gradle 10.

You can use '--warning-mode all' to show the individual deprecation warnings and determine if they come from your own scripts or plugins.

For more on this, please refer to https://docs.gradle.org/9.2.0/userguide/command_line_interface.html#sec:command_line_warnings in the Gradle documentation.

BUILD FAILED in 629ms
12 actionable tasks: 2 executed, 1 from cache, 9 up-to-date

Desktop (please complete the following information):

• OS: MacOS 26
• Java version [e.g. 21]: openjdk 25.0.2 2026-01-20