Upgrading to plugin 2.13.1 causes build failures

[matthewjamesadam]

We have recently tried to upgrade to 2.13.1 so that we can build plugins for JB 2026 IDEs. After updating I get the attached opaque error message -- I am following the error instructions to file this as a bug.

I fully admit I am not a JB plugin expert so perhaps something here is obvious -- if true, apologies. Any help would be appreciated. Thanks!

[hsz]

Could you please share any details about the issue you're facing?

[matthewjamesadam]

Apologies @hsz -- I'm not sure what happened but the logs didn't attach.

Here are the logs. The issue is that the build fails -- mostly I'm just following the instructions in the build output to file an issue here. Thanks!

Untitled-1.txt

[matthewjamesadam]

And to outline the changes we made:

In our build.gradle.kts changed:

id("org.jetbrains.intellij.platform") version "2.4.0"

to:

id("org.jetbrains.intellij.platform") version "2.13.1"

[hsz]

Most likely, something's off with Kotlin or Gradle versions. Can you please share your build.gradle.kts or prepare a minimal reproducible project so I can verify it on my end?

[halirutan]

@matthewjamesadam Did you also update your Gradle version and wrapper to 9.4.1 (or at least to 9+)?

Edit: If you like, you can check what I changed in the Key Promoter X when updating it from an ancient version to the current one

halirutan/IntelliJ-Key-Promoter-X@3943014

[matthewjamesadam]

@halirutan thanks for the feedback -- we are using gradle 9.2.1 (I haven't changed it recently) -- I also tried building with gradle 9.4.1 and got the same result.

I've cut our build.gradle.kts down to a small file (follows) and it still fails -- gradle won't even sync in IntelliJ. I'm going to guess that this is a problem outside of intellij-platform-gradle-plugin -- this plugin is held in a monorepo with many other Kotlin projects and I suspect the version of kotlin used in the rest of the monorepo, or the serialization library, is causing problems. I will keep looking into this and will let you know if I figure it out.

plugins {
    id("java")
    id("org.jetbrains.intellij.platform") version "2.13.1"
    kotlin("jvm")
}

repositories {
    mavenCentral()
    google()
    gradlePluginPortal()

    intellijPlatform {
        defaultRepositories()
    }
}

dependencies {
    implementation(project(":projects:libs:lib-kotlin", configuration = "default"))
}

intellijPlatform {
    pluginConfiguration {
    }
}

dependencies {
    implementation(libs.intellij.structure.plugin)

    intellijPlatform {
        intellijIdea("2026.1")
        pluginVerifier()
        bundledPlugin("Git4Idea")
    }
}

[hsz]

Thanks for sharing, @matthewjamesadam
Adding a dependency on Kotlin is most likely the reason for your issues:

dependencies {
    implementation(project(":projects:libs:lib-kotlin", configuration = "default"))
}

Please remove that and try again. The IntelliJ Platform already includes bundled Kotlin, Coroutines, and Serialization libraries, so introducing a different version of any of these libraries may lead to unexpected problems.