Add a workaround for KT-72933

Author: osipxd

build-settings-logic/src/main/kotlin/ConfigurationCacheWorkarounds.kt

@@ -0,0 +1,43 @@
+/*
+ * Copyright 2014-2025 JetBrains s.r.o and contributors. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+import sun.misc.Unsafe
+import java.lang.reflect.Field
+
+@Suppress("UNCHECKED_CAST")
+internal object ConfigurationCacheWorkarounds {
+    private val ignoreBeanFieldsField = Class.forName("org.gradle.internal.serialize.beans.services.Workarounds")
+        .getDeclaredField("ignoredBeanFields")
+        .apply { isAccessible = true }
+
+    private val unsafe = runCatching {
+        Unsafe::class.java.getDeclaredField("theUnsafe")
+            .apply { isAccessible = true }
+            .get(null) as Unsafe
+    }.getOrNull()
+
+    private var ignoreBeanFields = ignoreBeanFieldsField.get(null) as Array<Pair<String, String>>
+        set(value) {
+            val isSet = runCatching { unsafe?.setFinalStatic(ignoreBeanFieldsField, value) }.getOrNull() != null
+            if (isSet) {
+                field = value
+            } else {
+                // If we can't set a new array to the field, fallback to replacing array's content with new values
+                for (i in 0..minOf(field.lastIndex, value.lastIndex)) field[i] = value[i]
+            }
+        }
+
+    /** Registers fields that should be excluded from configuration cache. */
+    fun addIgnoredBeanFields(vararg fields: Pair<String, String>) {
+        ignoreBeanFields = fields as Array<Pair<String, String>> + ignoreBeanFields
+    }
+}
+
+@Suppress("DEPRECATION")
+private fun Unsafe.setFinalStatic(field: Field, value: Any) {
+    val fieldBase = staticFieldBase(field)
+    val fieldOffset = staticFieldOffset(field)
+
+    putObject(fieldBase, fieldOffset, value)
+}

build-settings-logic/src/main/kotlin/ktorbuild.configuration-cache.settings.gradle.kts

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2014-2025 JetBrains s.r.o and contributors. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+import org.gradle.kotlin.dsl.support.serviceOf
+
+val features = serviceOf<BuildFeatures>()
+
+if (features.configurationCache.requested.get()) {
+    // KT-72933: Storing these fields leads to OOM
+    ConfigurationCacheWorkarounds.addIgnoredBeanFields(
+        "transformationParameters" to "org.jetbrains.kotlin.gradle.plugin.mpp.MetadataDependencyTransformationTask",
+        "parameters" to "org.jetbrains.kotlin.gradle.targets.native.internal.CInteropMetadataDependencyTransformationTask",
+    )
+
+    // Mark these tasks as incompatible with configuration cache as we partially exclude their state from CC
+    gradle.beforeProject {
+        tasks.matching { it::class.java.simpleName.contains("MetadataDependencyTransformationTask") }
+            .configureEach { notCompatibleWithConfigurationCache("Workaround for KT-72933") }
+    }
+
+    println("Configuration Cache: Workaround for KT-72933 was applied")
+}

gradle.properties

@@ -56,6 +56,9 @@ kotlin.mpp.applyDefaultHierarchyTemplate=false
 kotlin.apple.xcodeCompatibility.nowarn=true
 kotlin.suppressGradlePluginWarnings=IncorrectCompileOnlyDependencyWarning
 kotlin.daemon.useFallbackStrategy=false
+# Enable new project model to be prepared for enabling isolated projects
+# TODO: Remove when we enable isolated projects in Gradle
+kotlin.kmp.isolated-projects.support=enable
 
 # dokka
 # workaround for resolving platform dependencies, see https://github.com/Kotlin/dokka/issues/3153

settings.gradle.kts

@@ -12,6 +12,7 @@ plugins {
     id("org.gradle.toolchains.foojay-resolver-convention") version "0.9.0"
     id("conventions-dependency-resolution-management")
     id("conventions-develocity")
+    id("ktorbuild.configuration-cache")
 }
 
 rootProject.name = "ktor"