On iOS I’ve got

-Xobjc-generics

enabled. However when trying to run a release build I get:

cannot specialize non-generic type

Seems like Kotlin Generics are only working for debug builds. Is there any additional config needed?

Can you post your detailed config and error message in context?

Sorry it took me a bit longer. Using Kotlin 1.3.61:

kotlin {
  def sdkName = System.getenv("SDK_NAME")
  if (sdkName != null && sdkName.startsWith("iphoneos")) {
    iosArm64("ios")
  } else {
    iosX64("ios")
  }

  cocoapods {
    summary = "BeCoachShared"
    homepage = "<https://becoach.app/>"
  }

  // When using cocoapods plugin we can't configure the Framework directly.
  targets.ios.binaries
      .findAll { it instanceof org.jetbrains.kotlin.gradle.plugin.mpp.Framework }
      .every {
        it.embedBitcode("YES".equals(System.getenv("ENABLE_BITCODE")) ? "bitcode" : "marker")
        it.setFreeCompilerArgs(it.getFreeCompilerArgs() + "-Xobjc-generics")
      }
}

When trying to run my iOS App for an iPhone 11 with a Debug Build Configuration everything works. When I switch to release I’m getting: ErrorHandling.swift7344: Cannot specialize non-generic type ‘SuccessFailure’ This is the generated class (Release Build Configuration):

__attribute__((swift_name("SuccessFailure")))
@interface DatabaseSuccessFailure : KotlinBase
@end;

which obviously is missing the Type declaration. This is the generated class (Debug Build Configuration):

__attribute__((swift_name("SuccessFailure")))
@interface DatabaseSuccessFailure<T> : KotlinBase
@end;

in Kotlin the class looks like this:

// T : Any so that Swift understand that T can never be null.
sealed class SuccessFailure<T : Any>