Delegate kotlin.* classes to parent in RecipeClassLoader#7695
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When both the parent and a recipe jar ship kotlin-stdlib, types like kotlin.jvm.functions.Function1 get defined by both loaders. Jackson (parent-loaded) interacting with jackson-module-kotlin from the recipe jar then trips a LinkageError on loader-constraint violations. Mirror the existing slf4j/jackson rule and delegate kotlin.* to the parent, with the existing fallback to the child when the parent lacks the class. See moderneinc/customer-requests#2372.
nmck257
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May 15, 2026
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Summary
When both the parent and a recipe jar ship kotlin-stdlib, types like
kotlin.jvm.functions.Function1get defined by both loaders, and Jackson (parent-loaded) interacting withjackson-module-kotlinfrom the recipe jar trips aLinkageErroron loader-constraint violations. Mirror the existing slf4j/jackson rule and delegatekotlin.*to the parent, with the existing fallback to the child when the parent lacks the class.Test plan
kotlinClassesShouldDelegateToParenttest: parent and child both definekotlin.jvm.functions.Function1; asserts the parent's copy wins.kotlinClassesFallBackToChildWhenParentLacksThemtest: parent has no kotlin classes; the recipe loader still resolves the class from the child../gradlew :rewrite-core:test --tests RecipeClassLoaderTestis green.