Changelog

Backend. Wasm

• KT-82649 K/Wasm: Rewrite StringBuilder to use JsString
• KT-83995 K/Wasm: 2.3.0 -> 2.3.20-Beta1 degradation in arrow tests
• KT-83839 K/Wasm: CMP. Load time on Safari significantly increased with Kotlin = 2.3.20-Beta1

Compiler

• KT-83372 compileDebugKotlinAndroid hangs in 2.3.0 with SQLDelight
• KT-83849 False-positive NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS for Optional.orElse(null) call
• KT-84192 "Member overrides different '[@Throws](https://github.com/Throws)' filter from" caused by overriding in different module
• KT-83697 Native: increased bitcode produced with enabled safe casts
• KT-83984 Data races around kotlinx.serialization plugin protobuf extensions registration
• KT-83031 K2: unstable resolution of EnhancedNullability from type-use NotNull in presence of unused code
• KT-83824 Delegated property in Gradle DSL fails to compile
• KT-81700 flaky overload resolution behaviors (false-positive errors, different final candidates, compile-time failures)
• KT-78443 Refactor session component initialization for multi-target compilation

Compose compiler

• b/481953005, b/481769383 Cache stability inference results during session
• b/481735904 Fix Compose codegen crash in inline function
• b/479646393 Add groups to inline functions with two or more inline parameters

JavaScript

• KT-83572 KJS/Wasm: Cannot access [@JsModule](https://github.com/JsModule)-declared class from non-modular project
• KT-84134 KJS/CMP: "IrLinkageError: Function 'get' can not be called: No function found for symbol"
• KT-64951 Kotlin-Multiplatform does not allow JSExport of expect

Klibs

• KT-84273 [Klib] Added IrOffsetsChecker broke backward klib compatibility

Native

• KT-83542 Switch the default GC back to PMCS in 2.3.20-RC

Native. ObjC Export

• KT-83736 Objective-C export with objcExportBlockExplicitParameterNames generates invalid block signature when lambda parameter is named id

Tools. Build Tools API

• KT-83971 BTA: OperationCancelledException cannot be thrown properly from isolated classloader

Tools. Compiler plugins. Compose

• KT-84055 Reference to lambda in lambda in function 'TextField' can not be evaluated

Tools. Gradle

• KT-82885 Run tests against Gradle 9.3.0

Tools. Gradle. Multiplatform

• KT-82090 Kotlin JVM + Android Shared Source set fails Import with the Project Isolation enabled
• KT-83917 compileCommonMainKotlinMetadata fails in CMP core repository with Kotlin 2.3.20-Beta1