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[FEATURE] Support for Java 26 (Unsupported class file major version 70) #4019

Description

@mplushnikov

Some Users are currently testing the new HTTP/3 client features in the early access builds of Java 26. While the project compiles and runs via the command line with Maven, it fails when building through IntelliJ IDEA (latest EAP).

The issue seems to be that Lombok's internal ASM version does not yet recognize the class file major version 70 used by Java 26.

Steps to reproduce:

  • Use a Java 26 EA build (JDK 26).
  • Use the latest Lombok version.

Attempt to compile a project containing Lombok annotations (e.g., @SneakyThrows or any bytecode-transforming annotation) using the IntelliJ JPS builder.

Expected behavior
The project should compile without errors, similar to how it behaves under Java 25.

Actual behavior
The compilation fails with a java.lang.IllegalArgumentException: Unsupported class file major version 70 originating from Lombok's PostCompiler.

Stacktrace

java: Error during the transformation of 'x.y.z.Foo'; post-compiler 'lombok.bytecode.SneakyThrowsRemover' caused an exception: java.lang.IllegalArgumentException: Unsupported class file major version 70
  	at org.lombokweb.asm.ClassReader.<init>(ClassReader.java:200)
  	at org.lombokweb.asm.ClassReader.<init>(ClassReader.java:180)
  	at org.lombokweb.asm.ClassReader.<init>(ClassReader.java:166)
  	at lombok.bytecode.AsmUtil.fixJSRInlining(AsmUtil.java:37)
  	at lombok.bytecode.SneakyThrowsRemover.applyTransformations(SneakyThrowsRemover.java:46)
  	at lombok.core.PostCompiler.applyTransformations(PostCompiler.java:44)
  	at lombok.core.PostCompiler$1.close(PostCompiler.java:87)
    ... (rest of the stacktrace)

Environment:
Java version: Java 26 EA
Lombok version: 1.18.42
IDE: IntelliJ IDEA (Latest EAP)
Build tool: Maven / JPS

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