fix: force kotlin-stdlib to 2.0.

Author: autonomousapps

build-logic/convention/src/main/kotlin/com/autonomousapps/convention/LibKotlinConventionPlugin.kt

@@ -2,28 +2,27 @@
 // SPDX-License-Identifier: Apache-2.0
 package com.autonomousapps.convention
 
-import com.autonomousapps.convention.internal.kotlin.configureDokka
-import com.autonomousapps.convention.internal.kotlin.configureKotlin
+import com.autonomousapps.convention.internal.kotlin.KotlinConfigurer
 import com.vanniktech.maven.publish.JavadocJar
 import com.vanniktech.maven.publish.KotlinJvm
 import com.vanniktech.maven.publish.MavenPublishBaseExtension
 import org.gradle.api.Plugin
 import org.gradle.api.Project
-import org.gradle.api.artifacts.VersionCatalogsExtension
 
 public abstract class LibKotlinConventionPlugin : Plugin<Project> {
 
   override fun apply(target: Project): Unit = target.run {
     pluginManager.apply("org.jetbrains.kotlin.jvm")
     BaseConventionPlugin(this).configure()
 
-    val versionCatalog = extensions.getByType(VersionCatalogsExtension::class.java).named("libs")
-
-    configureDokka(versionCatalog)
-    configureKotlin(versionCatalog)
+    configureKotlin()
     configurePublishing()
   }
 
+  private fun Project.configureKotlin() {
+    KotlinConfigurer(this).configure()
+  }
+
   private fun Project.configurePublishing() {
     extensions.getByType(MavenPublishBaseExtension::class.java).run {
       configure(

build-logic/convention/src/main/kotlin/com/autonomousapps/convention/PluginConventionPlugin.kt

@@ -2,8 +2,7 @@
 // SPDX-License-Identifier: Apache-2.0
 package com.autonomousapps.convention
 
-import com.autonomousapps.convention.internal.kotlin.configureDokka
-import com.autonomousapps.convention.internal.kotlin.configureKotlin
+import com.autonomousapps.convention.internal.kotlin.KotlinConfigurer
 import com.gradle.publish.PublishTask
 import com.vanniktech.maven.publish.GradlePublishPlugin
 import com.vanniktech.maven.publish.MavenPublishBaseExtension
@@ -27,9 +26,8 @@ public abstract class PluginConventionPlugin : Plugin<Project> {
 
     val versionCatalog = extensions.getByType(VersionCatalogsExtension::class.java).named("libs")
 
-    configureDokka(versionCatalog)
     configureGroovy(versionCatalog)
-    configureKotlin(versionCatalog)
+    configureKotlin()
     configurePlugins()
     configurePublishing()
     disableConfigurationCache()
@@ -45,6 +43,10 @@ public abstract class PluginConventionPlugin : Plugin<Project> {
     }
   }
 
+  private fun Project.configureKotlin() {
+    KotlinConfigurer(this).configure()
+  }
+
   /**
    * @see <a href="https://github.com/gradle/gradle/issues/22600">Enable stricter validation of plugins by default for validatePlugins task</a>
    */

build-logic/convention/src/main/kotlin/com/autonomousapps/convention/internal/kotlin/KotlinConfigurer.kt

@@ -0,0 +1,71 @@
+// Copyright (c) 2025. Tony Robalik.
+// SPDX-License-Identifier: Apache-2.0
+package com.autonomousapps.convention.internal.kotlin
+
+import org.gradle.api.Project
+import org.gradle.api.artifacts.VersionCatalogsExtension
+import org.jetbrains.kotlin.gradle.dsl.JvmTarget
+import org.jetbrains.kotlin.gradle.dsl.KotlinJvmProjectExtension
+import org.jetbrains.kotlin.gradle.dsl.KotlinVersion
+import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
+
+internal class KotlinConfigurer(private val project: Project) {
+
+  private val versionCatalog = project.extensions.getByType(VersionCatalogsExtension::class.java).named("libs")
+
+  private val dokka = versionCatalog.findLibrary("kotlin.dokka").get()
+  private val javaTarget = versionCatalog.findVersion("javaTarget").orElseThrow().requiredVersion
+  private val kotlin = versionCatalog.findVersion("kotlin").get().requiredVersion
+
+  // this function expects strings of the form 2.x, not 2.x.y
+  private val kotlinVersion = KotlinVersion.fromVersion(kotlin.substringBeforeLast('.'))
+
+  private val kotlinJvmExtension = project.extensions.getByType(KotlinJvmProjectExtension::class.java)
+
+  fun configure(): Unit = project.run {
+    kotlinJvmExtension.explicitApi()
+
+    configureDokka()
+    configureKotlinTarget()
+    configureKotlinVersion()
+  }
+
+  private fun Project.configureDokka() {
+    dependencies.add("dokkaHtmlPlugin", dokka)
+  }
+
+  private fun Project.configureKotlinTarget() {
+    tasks.withType(KotlinCompile::class.java).configureEach { t ->
+      t.compilerOptions {
+        // Ensure compatibility with Gradle 8.x. See https://docs.gradle.org/9.0.0/userguide/compatibility.html.
+        apiVersion.set(kotlinVersion)
+        languageVersion.set(kotlinVersion)
+        jvmTarget.set(JvmTarget.fromTarget(javaTarget))
+        freeCompilerArgs.add(
+          // equivalent to JavaCompile's `options.release`
+          "-Xjdk-release=$javaTarget",
+        )
+      }
+    }
+  }
+
+  /**
+   * @see <a href="https://github.com/autonomousapps/dependency-analysis-gradle-plugin/issues/1537#issuecomment-3293306966">Issue 1537</a>
+   */
+  private fun Project.configureKotlinVersion() {
+    configurations.configureEach { c ->
+      if (c.isCanBeResolved) {
+        c.resolutionStrategy { r ->
+          r.eachDependency { details ->
+            val requested = details.requested
+
+            if (requested.group == "org.jetbrains.kotlin" && requested.name == "kotlin-stdlib") {
+              details.useVersion(kotlin)
+              details.because("Downgrading the stdlib for enhanced compatibility")
+            }
+          }
+        }
+      }
+    }
+  }
+}