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Kotlin 1.4.20

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@woainikk woainikk released this 19 Nov 10:57
· 23 commits to 1.4.20 since this release



  • KT-42121 Deprecate Kotlin Android Extensions compiler plugin
  • KT-42267 Platform declaration clash error in IDE when using
  • KT-42406 Long or infinite code analysis on simple files modification

Backend. Native

  • KT-27534 Bridges to Nothing-returning methods have incorrect signature
  • KT-30284 Native: Nothing? type for expression override and crash
  • KT-36430 Optimize when with in range cases
  • KT-38787 Missing optimization for "in range" check
  • KT-39100 Make Native behaviour of property initialization consistent with JVM
  • KT-39798 Override equals/hashCode in functional interface wrappers on Native
  • KT-39800 equals/hashCode on adapted function references on Native
  • KT-41394 Compilation failed: Backend Internal error: Exception during IR lowering
  • KT-41907 Framework test segfaults on GC on watchos_x86 compiled with -opt


New Features

  • KT-21147 JEP 280: Indify String Concatenation (StringConcatFactory)
  • KT-34178 Scripts should be able to access imports objects
  • KT-35549 Support kotlin-android-extensions in JVM IR backend (for use with Jetpack Compose projects)
  • KT-31567 Support special semantics for underscore-named catch block parameters

Performance Improvements

  • KT-20571 Coroutines: Reduce number of local variables stored at suspension point
  • KT-28016 Coroutine state-machines spill/unspill shall be optimized using data-flow analysis
  • KT-33394 UI freezes triggered by QualifiedExpressionResolver.resolveToPackageOrClassPrefix
  • KT-36814 Support optimized delegated properties in JVM_IR
  • KT-36829 Optimize 'in' expressions (operator fun contains) in JVM_IR
  • KT-41741 NI: "AssertionError: Empty intersection for types" with generic Java collection
  • KT-42195 NI: prohibitively long compilation time for values of nested data structures with type inference
  • KT-42221 Native compiler never finishes frontend phase after migrating to Kotlin 1.4.10


  • KT-11713 Refine visibility check for synthetic property with protected setter
  • KT-16222 Coroutine should be clearing any internal state as soon as possible to avoid memory leaks
  • KT-25519 Extra inline marks inside suspending function callable reference bytecode
  • KT-33226 Object INSTANCE field not annotated with NotNull in generated bytecode
  • KT-35495 FIR: forbid non-Java synthetic properties
  • KT-35651 Kotlin stdlib has greater resolution priority than jars added via @file:DependsOn annotation
  • KT-35716 Using @JvmOverloads in @JvmStatic functions in interface companion objects causes a ClassFormatError
  • KT-35730 FIR: consider creating fake overrides for objects
  • KT-36951 IllegalStateException: Expected some types: Throwing exception when there is a type parameter upper bound for itself
  • KT-37321 [FIR] Support java array in type argument
  • KT-37431 [FIR] Support Builder Inference
  • KT-38272 FIR2IR: use lazy IR symbols for externals & fake overrides
  • KT-38333 FIR: CCE on red code with assignment used as expression
  • KT-38334 FIR: CCE when resolving try-as-expression
  • KT-38336 FIR: NPE with corrupted numeric constant literal
  • KT-38397 FIR: Exception while resolving contract definition
  • KT-38444 [FIR] Invoke extension lambda with safe call
  • KT-38470 FIR: ConeDefinitelyNotNullType in signature
  • KT-38471 FIR: ConeIntersectionType in signature
  • KT-38925 Internal error: wrong bytecode generated. (AssertionError: int type expected, but null was found in basic frames)
  • KT-38989 FIR: Refine sealed classes exhaustiveness in case of sealed subclass
  • KT-38992 FIR: Refine type resolution for inner classes
  • KT-39000 FIR: Support smartcast after reference equality check
  • KT-39005 FIR: Resolve plusAssign in a dependent context
  • KT-39008 FIR: Investigate strange effect of type alias and not-nullable bound on inference
  • KT-39012 FIR: Inference doesn't get through elvis to lambda parameter
  • KT-39028 FIR: Strange resolution to synthetic property with implicit extension receiver while there's an explicit receiver
  • KT-39032 FIR: Ambiguity in member scope of a type parameter with multiple bounds
  • KT-39033 FIR: Ambiguity when calling generic overridden property
  • KT-39034 FIR: Support nested extension function types
  • KT-39040 FIR: Deserialize annotations from compiled Kotlin binaries
  • KT-39043 FIR: Bare types incorrectly work with type aliases
  • KT-39044 FIR: Add fillInStackTrace to member scope of kotlin.Throwable
  • KT-39046 FIR: Implicit types in lambdas left when call argument is a type cast
  • KT-39048 FIR: Inference fails with integer literal used as Comparable
  • KT-39050 FIR: Type resolver doesn't see nested classes from super class of a local class
  • KT-39070 FIR: Ambiguity on super calls to hashCode/equals when having super interface and class
  • KT-39072 FIR: Subtyping check doesn't affect nullability of safe-call receiver
  • KT-39076 FIR: Synthetic property is not a var because of @nullable annotation on parameter
  • KT-39080 FIR: Smart casts remain incorrect if lambda is present in when branch
  • KT-39374 Wrong bytecode generated for suspend function call with EXACTLY_ONCE lambda capturing a variable initialized in when-subject
  • KT-39621 [FIR] Support when exhaustiveness checker for java enums
  • KT-40135 JVM IR does not generate restricted suspend lambdas
  • KT-40382 Missing proper jvmSignature for synthesized equals/hashCode/toString in inline classes
  • KT-40605 JVM IR: IndexOutOfBoundsException caused by inner class passed to generic outer class method with Nothing type argument
  • KT-40664 JVM: No bounds check in optimization of ULong in UInt..UInt
  • KT-40665 JVM: No resolved function check when optimizing in/contains with mismatched bound types
  • KT-41014 FIR2IR: when/where/how to determine the presence of a backing field for a property
  • KT-41018 FIR2IR: sort members during de/serialization
  • KT-41144 False positive "Redundant spread operator" in when statement and generic vararg argument
  • KT-41218 HMPP: arrayList declarations are visible both from stdlib-common and stdlib-jvm and lead to false-positive resolution ambiguity in IDE
  • KT-41374 JVM / IR: NoSuchMethodError in Android project compiler caused by combination of inline classes and coroutines
  • KT-41388 NI: Backend Internal error: Exception during IR lowering
  • KT-41429 Inline class returned from suspend function should be boxed on resume path
  • KT-41465 JVM / IR: "AssertionError: inconsistent parent function for CLASS LAMBDA_IMPL CLASS name" caused by inline method call into multiple constructors
  • KT-41484 JVM IR: support -Xemit-jvm-type-annotations
  • KT-41668 JVM IR: incorrect enclosing constructor for lambdas in initializers of inner classes
  • KT-41669 JVM IR: incorrect hashCode intrinsic is used in JVM target 1.8 for generic type substituted with primitive
  • KT-41693 NI: Type inference in nested expression incorrectly assumes non-nullable return type of Java function, causing NullPointerException
  • KT-41729 NI: UnsupportedOperationException with invalid callable reference
  • KT-41761 JVM IR: CCE from backend on generating typeOf for non-reified type parameter with star projection in upper bound
  • KT-41789 Missing DebugMetadata in inlined suspend lambda
  • KT-41913 NI: Kotlin 1.4 type inference breaks valid code
  • KT-41934 NI: a type variable for lambda parameter has been inferred to nullable type instead of not null one
  • KT-42005 JVM / IR: "NullPointerException: Parameter specified as non-null is null" when toString is called on inline class with not primitive property
  • KT-42450 NI: "IllegalStateException: Error type encountered: NonFixed:" with coroutines
  • KT-42523 Missed DefaultImpls for interface in -jvm-default=all mode on inheriting it from interface compiled in old scheme
  • KT-42524 Wrong specialization diagnostic is reported on inheriting from java interface with default with -Xjvm-default=all-compatibility
  • KT-42546 HMPP: incorrect subtyping of nullable types & overload resolution ambiguity on using and expect-function declaration with nullable expect in a signature
  • KT-17691 Wrong argument order in resolved call with varargs
  • KT-25114 Prohibit @JvmStatic on functions in private companions
  • KT-33917 Prohibit to expose anonymous types from private inline functions
  • KT-35870 Forbid secondary enum class constructors which do not delegate to the primary constructor
  • KT-39098 NI: parameter of anonymous function can be inferred to Any? if another parameter's type is specified
  • KT-41176 NI with Gson: "ClassCastException: java.util.ArrayList cannot be cast to java.lang.Void"
  • KT-41194 ClassCastException on returning Result.failure from lambda within suspend function
  • KT-42438 NI: ClassCastException: cannot be cast to java.lang.Void caused by when statement in run function
  • KT-42699 False positive NON_JVM_DEFAULT_OVERRIDES_JAVA_DEFAULT diagnostic in new jvm-default modes
  • KT-42706 Kotlin 1.4 infers generic is Nothing instead of actual Foo class (Android project)

Docs & Examples

  • KT-42318 No documentation for kotlin.js.js


New Features

  • KT-20775 More kotlin kinds in new kotlin file/class menu
  • KT-31331 Improve: Optimize Import should remove unused unresolved imports
  • KT-31500 Smart enter: support get() clause
  • KT-39231 Injection: Add receiver of kotlin.text.toPattern to standard Kotlin injections
  • KT-39844 Add specific highlight for Enum class

Performance Improvements

  • KT-39353 Implement EnterBetweenBracesNoCommitDelegate
  • KT-39720 A lot of freezes in Kotlin project
  • KT-41634 Deadlock in org.jetbrains.kotlin.idea.framework.LibraryEffectiveKindProviderImpl.getEffectiveKind
  • KT-41936 Impossible to work with Kotlin 1.4 in 202 idea, idea eats all cpu


  • KT-10790 "Move statement up" for @file-targeted annotation moves package declaration to bottom of file
  • KT-15262 "Generate toString()" is ignoring property if it has a getter
  • KT-24352 Method separators: displayed between properties, not displayed between companion object and function
  • KT-29364 "Extend selection" can't select lambda body with parameters
  • KT-32403 Clickable links in annotation parameters (like in TODOs)
  • KT-32409 Organizing imports should not remove imports while there are unresolved symbols
  • KT-34566 Too small indent after line break for multi line strings
  • KT-34587 "Move statement down" doesn't work for statement in constructor with end-of-line comment
  • KT-34705 "Move statement down" for penultimate statement with end-of-line comment in constructor leads to moving comma to the end of comment
  • KT-34707 "Move statement up" for last statement with end-of-line comment in constructor leads to moving comma to the end of comment
  • KT-35424 FIR IDE: Kotlin project does not see stdlib
  • KT-35732 URLs in String literals are not clickable
  • KT-35859 Language injection doesn't work with named arguments in different position
  • KT-37210 UAST: KtLightClassForSourceDeclaration.isInheritor sometimes returns the wrong result
  • KT-37219 File level OptIn annotation is not recognized by the IDE
  • KT-38959 IDE: False negative EXPLICIT_DELEGATION_CALL_REQUIRED, "IllegalArgumentException: Range must be inside element being annotated"
  • KT-39398 Wrong import of unrelated object member is suggested for receiver
  • KT-39457 Separate decompiled declarations Light implementation from LightClasses infrastructure
  • KT-39899 KotlinOptimizeImportsRefactoringHelper: ISE: Attempt to modify PSI for non-committed Document
  • KT-40578 UAST: write accesses to Kotlin properties should resolve to setter
  • KT-41290 KotlinClassViaConstructorUSimpleReferenceExpression resolves to PsiMethod instead of PsiClass
  • KT-42029 HMPP, IDE: NPE from FacetSerializationKt.getFacetPlatformByConfigurationElement on project opening
  • KT-43202 On 1.4.20-RC version AS ask for xml compatibility update for EAP version of plugin
  • KT-42883 No highlighting for elements marked as @deprecated in stdlib

IDE. Android

  • KT-42406 Long or infinite code analysis on simple files modification
  • KT-42061 Highlighting is broken in Android activity
  • KT-41930 Android Studio 4.2 cannot start after updating to 1.4.20 plugin with error: Missing essential plugin:

IDE. Completion

  • KT-26235 Kotlin methods/fields don't have icons in Java completion

IDE. Debugger

  • KT-37486 Kotlin plugin keeps reference to stream debugger support classes after stream debugger plugin is disabled
  • KT-38659 Evaluate Expression: toString() on variable returns error when breakpoint is in commonTest sourceset
  • KT-39309 Debugger: Prolonged "Collecting data" for variables when breakpoint is inside respondHtml
  • KT-39435 "Collecting data..." in debugger variables view never finishes
  • KT-39717 Debugger shows "Collecting data..." forever for instances of some class
  • KT-40386 Memory leak detected: 'org.jetbrains.kotlin.idea.debugger.coroutine.view.XCoroutineView'
  • KT-40635 Coroutines Debugger: make IDE plugin accept coroutines 1.3.8-rc* versions as well
  • KT-41505 Coroutines Debugger: “Access is allowed from event dispatch thread with IW lock only.”

IDE. Decompiler, Indexing, Stubs

  • KT-28732 Stub file element types should be registered early enough
  • KT-41346 IDE: "AssertionError: Stub type mismatch: USER_TYPE!=REFERENCE_EXPRESSION" with CollapsedDumpParser class from IDEA SDK
  • KT-41859 File analysis never ending with kotlinx.cli (AssertionError: Stub type mismatch: TYPEALIAS!=CLASS)
  • KT-41640 "Project roots have changed" happened during indexing because of org.jetbrains.kotlin.idea.core.script.ucache.ScriptClassRootsUpdater$notifyRootsChanged increases overall indexing time.
  • KT-41646 "AssertionError: ContentElementType: FILE"; Code analysis never finishes on some files from my project

IDE. Gradle Integration

  • KT-34271 Support pureKotlinSourceFolders for MPP projects
  • KT-37106 Gradle + IDE integration: on creating source roots from Project tree IDEA creates incorrect settings
  • KT-38830 addTransitiveDependenciesOnImplementedModules performance is slowing down Android Studio Gradle Sync
  • KT-41703 Kotlin plugin not functional: PluginException: While loading class org.jetbrains.kotlin.idea.core.script.KotlinScriptDependenciesClassFinder

IDE. Gradle. Script

  • KT-35092 “Unable to get Gradle home directory” popup and no build.gradle.kts highlighting right after creating a new project
  • KT-37590 Wrong notification for precompiled build script
  • KT-39523 Go to Declaration navigates to decompiled classfile instead of sources in case of jumping to Gradle plugin sources in buildSrc
  • KT-39542 EA-218043: java.util.NoSuchElementException: No element of given type found (GradleBuildRootsManager)
  • KT-39790 List of standalone script should be saved between IDE restarts
  • KT-39910 build.gradle.kts isn't highlighted after import
  • KT-39916 init.gradle.kts isn't highlighted
  • KT-40243 gradle.kts: standalone script under build root isn't highlighted as standalone
  • KT-41141 Gradle Kotlin DSL: "cannot access 'java.lang.Comparable'. Check your module classpath" with empty JDK in Project structure
  • KT-41281 Multiple Script Definitions warning shown in git project having multiple Gradle projects

IDE. Hints

  • KT-32368 Rework Inline hints settings so that they look appropriate with the new UI in 2019.3
  • KT-38027 Support Code Vision feature in Kotlin
  • KT-42014 ClassNotFoundException in Android Studio 4.2 after installing 1.4.20 plugin

IDE. Hints. Parameter Info

  • KT-24172 Parameter info marks signature as inapplicable when using argument labels
  • KT-41617 Parameter Info shows nothing inside already present type arguments of supertype
  • KT-41645 Add support for mixed named arguments to parameter info popup

IDE. Inspections and Intentions

New Features

  • KT-14578 Suggest "Convert lambda to reference" intention for generic extension function
  • KT-19321 Warn if method with nullable return type always returns non-null
  • KT-20718 Add a quick fix for "this class has no constructor" error on 'expect' annotation classes
  • KT-21223 Add inspection for incomplete destructuring
  • KT-22420 Intention to replace a = b with b.also { a = it }
  • KT-39930 Add inspection for nullable Boolean in if condition
  • KT-40016 Replace 'a.toLowerCase() == b.toLowerCase()' with 'a.equals(b, ignoreCase = true)' inspection
  • KT-40283 Inspection which replaces also/apply with nested forEach to onEach
  • KT-40769 Add intention to replace isBlank/isNotBlank method negation


  • KT-12222 Intention 'Convert to block body' should take nullability of overriden method into account when expression is of platform type
  • KT-14395 Lambda to Reference doesn't work for generic types
  • KT-15846 'Change lambda expression return type' quick fix does nothing
  • KT-15944 IDEA doesn't suggest to replace deprecated get set operator functions when it used as operator
  • KT-17222 "Convert reference to lambda" creates red code for method with default argument values
  • KT-18125 "Wrap with let {...}" intention not available in all cases
  • KT-20438 Naming convention inspections: factory functions that are named like classes are flagged
  • KT-24138 Incorrect behavior in "convert reference to lambda" with new inference enabled, on function reference with default arguments
  • KT-29844 "Create class from usage" should mark constructor of created class as internal if its parameters have internal visibility
  • KT-30928 "Show hints for suspend calls" is too easy to enable and hard to disable
  • KT-31749 "Surround with null check" produces incorrect check for 'in' expression
  • KT-32963 Don't suggest java directory of a JVM source set in multiplatform project as a target for Create actual quick fix
  • KT-33211 Quickfix "add parameter" for method references should infer functional type instead of KFunction
  • KT-33258 "Merge 'if's" intention drops comment before nested if
  • KT-34572 Convert to block body action improperly works with suppress annotations
  • KT-35128 Intention Convert member to extension hides property delegate text with single line comment
  • KT-35214 Intention Put parameters on one line: don't suggest if parameters has end-of-line comments
  • KT-35320 False positive "Replace explicit parameter 'x' with 'it'" in 'when' expression which returns lambda
  • KT-35525 False positive intention for 'run': "Convert to 'let'" when invoked without receiver
  • KT-35526 Intention "Eliminate argument of 'when'" is broken for 'when' expression without 'else' branch
  • KT-35805 FoldInitializerAndIfToElvis: should not add new line for multiline initializer
  • KT-36051 IfThenToSafeAccessInspection: do not report if condition is SENSELESS_COMPARISON
  • KT-37748 "Convert anonymous function to lambda expression" intention does not add necessary lambda type parameter
  • KT-37841 IllegalStateException after "add non-null asserted call" on nullable function reference
  • KT-38139 False negative "Add suspend modifier" quickfix when suspend function is called in inline lambda
  • KT-38267 False positive "Call on collection type may be reduced" with Java platform types: suggested to reduce 'mapNotNull' call to 'map'
  • KT-38282 False positive "Remove redundant spread operator" inspection with array as class property or fun argument
  • KT-38915 "Remove explicit type specification" intention should be disabled in explicit API mode
  • KT-38981 "Specify return type explicitly" inspection is not reported for declaration annotated with @PublishedApi in Explicit Api mode
  • KT-39026 'Specify return type explicitly' intention duplicates compiler warning in Explicit api mode
  • KT-39200 False positive "Redundant qualifier name" with same-named member object and companion property
  • KT-39263 False positive "Variable should be inlined" for override value in initialized object
  • KT-39311 Batch quick fix name for "Change file's package" is truncated
  • KT-39393 "Convert anonymous function to lambda expression" intention does not add necessary lambda type parameter for outer function
  • KT-39454 False positive "Unused symbol" with private anonymous object property
  • KT-39467 False negative "Move variable declaration into when" if a variable declaration is placed on a new line
  • KT-39490 'Wrap with ?.let' quickfix put the receiver in let lambda
  • KT-39552 Merge 'if's intention drops comment after nested if
  • KT-39604 "Package directive doesn't match file location" quick fix does not insert a space between keyword package and the package name
  • KT-39772 "Redundant 'Unit'" should support lambdas
  • KT-40215 "Create abstract function" quick fix suggested even though surrounding class is non-abstract
  • KT-40448 "Convert call chain into sequence": support functions added in Kotlin 1.4
  • KT-40558 False positive "Move to class body" intention on data class constructor property
  • KT-41338 False positive "Redundant 'asSequence' call" when Map.Entry properties are used.
  • KT-41615 "Unused equals expression" inspection: highlight whole expression with yellow background
  • KT-43037 Disable "Incomplete destructuring declaration" in 1.4.20


  • KT-20421 J2K: SUPERTYPE_NOT_INITIALIZED for object extending base class
  • KT-37298 J2K: implicit widening conversion for whole argument expression is transformed to cast on subexpression
  • KT-38879 J2K loses class annotations when converting class to object
  • KT-39149 J2K fails with augmented assignment operators when multiplying int by a non-int
  • KT-40359 J2K: Conversion of invalid octal numbers throws NumberFormatException
  • KT-40363 J2K: Converting HEX integer literal in for-loop throws NumberFormatException


  • KT-39319 KJS: Support debugging through new Intellij 202 API
  • KT-41328 KJS / Gradle: explicitApi mode doesn't work


  • KT-17926 IDE should show documentation for a class if the constructor has no docs.
  • KT-19069 KDoc: show default argument values
  • KT-37132 Redundant @NotNull annotation in a Quick Documentation pop-up

IDE. Misc

  • KT-39327 Get rid of usages of internal classes ModuleOrderEntryImpl and LibraryImpl
  • KT-40455 Improve support for EditorConfig

IDE. Navigation

  • KT-24616 Find usages fails to find setter usage
  • KT-38762 "Cannot access '' which is a supertype of 'kotlin.Int'" brokes navigation to constructor parameter declaration
  • KT-39558 Call Hierarchy shows references from KDoc
  • KT-40788 "Find usages" on Java getter overridden in Kotlin doesn't find synthetic property usage when it is called without base declaration
  • KT-40960 Unable to find usages in java of Kotlin constructor in library when sources is attached.

IDE. Project View

  • KT-37528 'Add Kotlin File/Class' suggests file before class

IDE. Refactorings

  • KT-19744 "Change Signature" is not available on constructor keyword in primary constructor
  • KT-22170 "Change Signature" ignores Java usages of methods marked with @JvmStatic
  • KT-37517 Invalid qualified name on copy-paste in build.gradle.kts

IDE. Run Configurations

  • KT-24463 MPP, Intellij runner: Run does not add resource directory to classpath
  • KT-36370 Hide run gutter icons for not yet implemented targets in multiplatform projects
  • KT-39788 MPP, Gradle runner: Run does not add resource directory to classpath on project reopen without Gradle sync

IDE. Scratch

  • KT-40557 IDE / Scratch: .kt files are treated as Kotlin scratches, opening fails

IDE. Script

  • KT-35825 Custom kotlin scripts have no project import suggestions in sub modules.
  • KT-39796 Performance of KotlinScriptDependenciesClassFinder
  • KT-41622 IDE: Kotlin scripting support can't find context class from same project
  • KT-41905 IDE / Script: FilePathPattern parameter in @KotlinScript annotation is not reflected correctly in Pattern / Extension
  • KT-42206 Cannot load script definitions using org.jetbrains.kotlin.jsr223.ScriptDefinitionForExtensionAndIdeConsoleRootsSource

IDE. Tests Support

  • KT-28854 Run/Debug configurations: "Redirect input from" option is not available for Kotlin apps
  • KT-36909 IDE attempts to run non-JVM tests launched from context menu as JVM ones
  • KT-37799 Don't show a target choice in context menu for a test launched on specific platform

IDE. Wizards

  • KT-37965 New Project wizard 1.4+: adding JUnit5 test library add dependency to runner
  • KT-40527 Node.JS application template in New Project Wizard
  • KT-40874 Open new project wizard help page in browser when clicking help button in new project wizard
  • KT-41417 Add react template to new project wizard
  • KT-41418 Wizard: Support KJS compiler choice
  • KT-41958 New project wizard: Backend/Console applications template with Groovy DSL missing compileTestKotlin block
  • KT-42372 Rrename test classes in wizard template to avoid name clashing


  • KT-38136 JS IR BE: add an ability to generate separate js files for each module and maybe each library
  • KT-38868 [MPP / JS / IR] IllegalStateException: "Serializable class must have single primary constructor" for expect class without primary constructor with @serializable annotation
  • KT-39088 [ KJS / IR ] IllegalStateException: Concrete fake override IrBasedFunctionHandle
  • KT-39367 KJS: .d.ts generation not working for objects
  • KT-39378 KJS / IR: "IllegalStateException: Operation is unsupported" with binaries.executable() and external function inside for loop with Iterator as return type
  • KT-41275 KJS / IR: "IllegalStateException: Can't find name for declaration FUN" caused by default value in constructor parameter
  • KT-41627 KJS / IR / Serialization: IllegalStateException: Serializable class must have single primary constructor
  • KT-37829 Kotlin JS IR: "Properties without fields are not supported" for companion objects
  • KT-39740 KJS / IR: Can't use Serializable and JsExport annotations at the same time

KMM Plugin

  • KT-41522 KMM: exceptions for Mobile Multiplatform plugin are suggested to report to Google, not JetBrains
  • KT-42065 [KMM plugin] iOS apps fail to launch on iOS simulator with Xcode 12


  • KT-41799 String.replace performance improvements
  • KT-43306 Deprecate createTempFile and createTempDir functions in
  • KT-19192 Provide file system extensions/APIs based on java.nio.file.Path
  • KT-41837 Remove @ExperimentalStdlibApi from CancellationException

Middle-end. IR

  • KT-40193 IR: pluginContext.referenceClass() is not resolving typealias
  • KT-41181 Kotlin/Native 1.4.0 compiler fails on data class with >120 fields

Native. C and ObjC Import

  • KT-41250 [C-interop] Stubs for C functions without parameter names should have non-stable names
  • KT-41639 Use LazyIR for enums and structs from cached libraries
  • KT-41655 Native: "type cnames.structs.S of return value is not supported here: doesn't correspond to any C type" when accessing forward-declared-struct-typed C global variable

Native. ObjC Export

  • KT-38641 Kotlin-Multiplatform: Objective-C description method name collision in Swift
  • KT-39206 New line characters in @deprecated annotation cause syntax error in Kotlin/native exported header

Native. Platform libraries

Native. Runtime. Memory

  • KT-42275 "Memory.cpp:1605: runtime assert: Recursive GC is disallowed" sometimes when using Kotlin from Swift deinit

Native. Stdlib

Tools. Android Extensions

  • KT-42342 Build fails with java.lang.RuntimeException: Duplicate class found in modules on checkDebug(Release)DuplicateClasses task when both kotlin-parcelize and kotlin-android-extensions plugins are applied

Tools. CLI

  • KT-35111 Extend CLI compilers help with link to online docs
  • KT-41916 Add JVM target bytecode version 15

Tools. Commonizer

  • KT-41220 [Commonizer] Short-circuit type aliases
  • KT-41247 [Commonizer] Missed supertypes in commonized class
  • KT-41643 Commonizer exception for targets [ios_x64], [macos_x64]
  • KT-42574 HMPP: unresolved platform.* imports in nativeMain source set

Tools. Compiler Plugins

  • KT-36329 Provide diagnostic in kotlinx.serialization when custom serializer mismatches property type
  • KT-40030 Move the Parcelize functionality out of the Android Extensions plugin

Tools. Gradle

  • KT-33908 Make Kotlin Gradle plugin compatible with the Gradle configuration cache
  • KT-35341 KotlinCompile: Symlinked friend paths are no longer supported

Tools. Gradle. JS

New Features

  • KT-35330 Allow to customise generated package.json
  • KT-39825 Provide single point of Webpack configuration in Gradle script
  • KT-41054 Support Yarn resolutions
  • KT-41340 Add flag to suppress kotlin2js deprecation message
  • KT-41566 Kotlin/JS: Support JavaScript Library distribution
  • KT-42222 KJS / Gradle: "Cannot find package@version in yarn.lock" when npm dependencies of one package but with different version are used in project
  • KT-42339 Support dukat binaries generation


  • KT-39515 package.json is regenerated without a visible reason
  • KT-39838 Kotlin/JS Gradle tooling: NPM dependencies of different kinds with different versions of the same package fail with "Cannot find package@version in yarn.lock"
  • KT-39995 Collect statistic about generateExternals feature
  • KT-40087 Kotlin/JS, IR backend: browserRun: update in continuous mode fails: "ENOENT: no such file or directory" referring output .js
  • KT-40159 Implement workaround / fix for webpack's "window is not defined"
  • KT-40178 Browser run task prints output in TeamCity format
  • KT-40201 Kotlin/JS: Gradle: public package.json has empty devDependencies {}
  • KT-40202 Kotlin/JS: Gradle: NPM version range operators are written into package.json as escape sequences
  • KT-40342 [Gradle, JS, Maven] "Cannot find module" generating fake NPM module from Maven dependendency
  • KT-40462 Collect statistic about usages of kotlin.js.generate.executable.default option
  • KT-40753 Type script definition file is not referenced as types in the package.json
  • KT-40812 Node.JS run working directory
  • KT-40865 KJS / Gradle: Registering a task with a type that directly extends AbstractTask has been deprecated
  • KT-40986 KJS / Gradle: BuildOperationQueueFailure when two different versions of js library are used as dependencies
  • KT-41125 Bump NPM versions in 1.4.20
  • KT-41286 KJS / Gradle: args order in runTask is changed in 1.4.0
  • KT-41475 KJS / Gradle: debug mode doesn't support custom launchers in karma config
  • KT-41662 Kotlin/JS: with CSS support mode == "extract" browser test fails even without CSS usage: "Error in config file!"
  • KT-42494 KJS / Gradle: "Configuration cache state could not be cached" caused by Gradle configuration cache

Tools. Gradle. Native

  • KT-39764 Assertions are disabled when running K/N compiler in Gradle process
  • KT-39999 Cocoapods plugin's dummy header cannot be compiled
  • KT-40999 CocoaPods Gradle plugin: Support custom cinterop options when declaring a pod dependency.
  • KT-41367 CocoaPods Gradle plugin: support git repository dependency
  • KT-41844 Kotlin 1.4.10 gradle configuration error with cocoapods using multiple multiplatform modules
  • KT-42531 Gradle task "podGenIos" fails if a Pod with a static library is added.

Tools. Incremental Compile

  • KT-37446 Incremental analysis for Java sources fails when run on JDK 11

Tools. Parcelize

  • KT-39981 Android parcel 'java.lang.VerifyError: Bad return type'
  • KT-42267 Platform declaration clash error in IDE when using
  • KT-42958 False positive IDE error on classes with kotlinx.parcelize.Parcelize on project initial import
  • KT-43290 Typo in error message for ErrorsParcelize.DEPRECATED_ANNOTATION - kotlin.parcelize instead of kotlinx.parcelize
  • KT-43291 Diagnostic deprecation messages should not be shown in case kotlin-android-extensions plugin is applied

Tools. Scripts

  • KT-37987 Kotlin script: hyphen arguments not forwarded to script
  • KT-38404 Scripting API: Provide Location of Annotation Usage
  • KT-39502 Scripting: reverse order of Severity enum so that ERROR > INFO
  • KT-42335 No "caused by" info about an exception that thrown in Kotlin Script

Tools. kapt

  • KT-25960 Interfaces annotated with JvmDefault has wrong modifiers during annotation processing
  • KT-37732 Kapt task is broken after update to 1.3.70/1.3.71
  • KT-42915 Kapt generates invalid stubs for static methods in interfaces in Kotlin 1.4.20-M2


File Sha256 11db93a4d6789e3406c7f60b9f267eba26d6483dcd771eff9f85bb7e9837011f
kotlin-native-prebuilt-linux-1.4.20.tar.gz b65cc8b1510b21f23587c5457a74dc9e7cd4a6294fa38c00d688837f8d52d554
kotlin-native-prebuilt-macos-1.4.20.tar.gz 9040ab932f01696b91608a6fd46f78b2f5f399d3a1132a344af6d83c7570f1a9 80c26b36b358a1a2fdba184a354a758b00b6f27e719dc2086cf5d287f92f12a3