I'm using Gradle 8.12, and when I try to use `HexFormat` inside `buildSrc`, I get the following erro...

# gradle

[Edoardo Luppi]

I'm using Gradle 8.12, and when I try to use HexFormat inside buildSrc, I get the following error.
Not sure how to actually fix it.

[mbonnin]

Something is setting apiLevel = 1.8, are you using kotlin-dsl maybe?

[Edoardo Luppi]

Yup!

[mbonnin]

This is my usual suspect

[mbonnin]

I would just use the regular org.jetbrains.kotlin.jvm plugin with sam-with-receiver plugin if you really need it

[Edoardo Luppi]

I think kotlin-dsl is what I use to declare plugins. For example, without it I cannot specify

gradlePlugin {
  plugins {
    register("projectModule") {
      ...
    }

    register("projectDocs") {
      ...
    }
  }
}

[mbonnin]

This is my usual suspect

suspect is confirmed
https://github.com/gradle/gradle/blob/a3cacb207fec727859be9354c1937da2e59004c1/pla[…]n/org/gradle/kotlin/dsl/plugins/dsl/KotlinDslCompilerPlugins.kt

[mbonnin]

For declaring plugins, you just need java-gradle-plugin

[Edoardo Luppi]

Damn, why such a low version. But thanks for finding out!

[mbonnin]

kotlin-dsl is doing wayyyy too many things

[mbonnin]

No idea why they set a language version that is not the same as the embedded version

[mbonnin]

Maybe it's for compatibility reasons but it's not Gradle's decision to make

[mbonnin]

Especially in buildSrc you control the build classpath so 🤷

[Edoardo Luppi]

After removing kotlin-dsl, I discovered its functions ended up EVERYWHERE in my Gradle files

[mbonnin]

If you want the syntaxic sugar for Kotlin (tasks.findByType<Foo>(), val task by registering , etc...), you can add gradleKotlinDsl() as a dependency

[mbonnin]

https://cookbook.gradle.org/plugin-development/kotlin-plugins/#difference-with-buildgradlekts-scripts

[Edoardo Luppi]

Thank you!

Btw, I found this

While it is supported to override the target language version when using the kotlin-dsl plugin to write build logic

Here https://github.com/gradle/gradle/pull/33041

[Edoardo Luppi]

However, it's not entirely clear what that means.

[mbonnin]

You can do some magic to override the kotlin-dsl defaults

[mbonnin]

https://handstandsam.com/2022/04/13/using-the-kotlin-dsl-gradle-plugin-forces-kotlin-1-4-compatibility/

[mbonnin]

This is a bit old now but I believe the concepts are similar

[mbonnin]

But really I would just use org.jetbrains.kotlin.jvm

[Edoardo Luppi]

I'm trying that route, but jvm + sam-with-receiver results in a gazillion errors

[Edoardo Luppi]

YESSS I DID IT!
I basically had to reproduce EXACTLY the kotlin-dsl setup, minus the Kotlin version obviously.

Lesson learnt, never blindly trust what is too easy to import and use, especially if for Gradle.

[Edoardo Luppi]

Thank you again!

[mbonnin]

That was one of the fastest solved buildSrc issues 😄