I have a module containing convention plugins and ...

# gradle

[Albert Chang]

I have a module containing convention plugins and I'm applying kotlin-dsl plugin to the module. When I try to use Enum.entries in the module, I get two errors:
• The feature "enum entries" is only available since language version 1.9
• This declaration needs opt-in. Its usage must be marked with '@kotlin.ExperimentalStdlibApi' or '@OptIn(kotlin.ExperimentalStdlibApi::class)'
Even if I add @OptIn(kotlin.ExperimentalStdlibApi::class), the first error still persists.
But if I use embedded-kotlin instead of kotlin-dsl, the errors go away. Any reasons why?
I'm using Gradle 8.6 and the bundled Kotlin version is 1.9.20.

[Albert Chang]

https://github.com/gradle/gradle/blob/e3764184b3ec7d3c88f5f610e4cc7062a0ec3593/pla[…]n/org/gradle/kotlin/dsl/plugins/dsl/KotlinDslCompilerPlugins.kt
Okay seems that Kotlin DSL plugin explicitly sets the language version to 1.8. Not sure why.

[vladimirsitnikov]

It is for backward compatibility: target 1.8 enables running the generated plugin with Gradle 8.0+

[Vampire]

Also check here: https://docs.gradle.org/current/userguide/compatibility.html

[Vampire]

Gradle 9 likely will increase the language version to 1.9 or whatever is current by then.

[Albert Chang]

Understood. Thank you!

[mbonnin]

If it's convention plugins that are not published, you don't really care about compatibility with other versions of Gradle, you can safely override that. This post is a bit old but still applies: https://handstandsam.com/2022/04/13/using-the-kotlin-dsl-gradle-plugin-forces-kotlin-1-4-compatibility/

[Vampire]

Except for one detail, starting with Gradle 8.1 you do not afterEvaluate anymore as also that plugin is not using it anymore since then. :-)

[mbonnin]

OMG yes afterEvaluate{} needs to die blob upside down !