Kotlin v1.3.21 release, JVM-based programming language

Kotlin JVM-based programming language

Kotlin is a statically typed, cross-platform, general-purpose programming language with type inference. Kotlin is designed to interoperate fully with Java, and the JVM version of its standard library depends on the Java Class Library, but type inference allows its syntax to be more concise. Kotlin mainly targets the JVM but also compiles to JavaScript or native code (via LLVM). Kotlin is sponsored by JetBrains, a software development company based in Prague, and is also backed by Google under the Kotlin Foundation.

Kotlin is officially supported by Google for mobile development on Android. Since the release of Android Studio 3.0 in October 2017, Kotlin is included as an alternative to the standard Java compiler. The Android Kotlin compiler lets the user choose between targeting Java 6 or Java 8 compatible bytecode.

Changelog v1.3.21



  • KT-29475 IllegalArgumentException at getAbstractTypeFromDescriptor with deeply nested expression inside function named with a right parenthesis
  • KT-29479 WARN: Could not read file on Java classes from JDK 11+
  • KT-29360 Kotlin 1.3.20-eap-100: This marker function should never been called. Looks like compiler did not eliminate it properly. Please, report an issue if you caught this exception.



  • KT-29486 Throwable: “Could not find correct module information” through IdeaKotlinUastResolveProviderService.getBindingContext() and ReplaceWithAnnotationAnalyzer.analyzeOriginal()
  • KT-29394 Kotlin 1.3.20 EAP: Excess log messages with kotlin.parallel.tasks.in.project=true
  • KT-29474 Regression in 1.3.20: Kotlin IDE plugin parses all *.gradle.kts files when any class in buildSrc is opened
  • KT-29290 Warning “function returning deferred with a name that does not end with async” should not be displayed for let/also/apply…
  • KT-29494 Don’t report BooleanLiteralArgumentInspection in batch (offline) mode with INFORMATION severity
  • KT-29525 turning on parallel tasks causes java.lang.NoClassDefFoundError: Could not initialize class kotlin.Unit sometimes
  • KT-27769 Change the DSL marker icon
  • KT-29118 Log polluted with multiple “Kotlin does not support alternative resolve” reports