As reported at robolectric/robolectric#11204, running local tests against Java 26 will raise the exception:
java.lang.IllegalArgumentException: Unsupported class file major version 70
at org.objectweb.asm.ClassReader.<init>(ClassReader.java:200)
at org.objectweb.asm.ClassReader.<init>(ClassReader.java:180)
at org.objectweb.asm.ClassReader.<init>(ClassReader.java:166)
at org.robolectric.internal.bytecode.ClassNodeProvider.createClassNode(ClassNodeProvider.java:24)
at org.robolectric.internal.bytecode.ClassNodeProvider.getClassNode(ClassNodeProvider.java:16)
at org.robolectric.internal.bytecode.InstrumentingClassWriter.typeInfo(InstrumentingClassWriter.java:114)
at org.robolectric.internal.bytecode.InstrumentingClassWriter.getCommonSuperClass(InstrumentingClassWriter.java:36)
at org.objectweb.asm.SymbolTable.addMergedType(SymbolTable.java:1286)
at org.objectweb.asm.Frame.merge(Frame.java:1311)
at org.objectweb.asm.Frame.merge(Frame.java:1218)
at org.objectweb.asm.MethodWriter.computeAllFrames(MethodWriter.java:1612)
at org.objectweb.asm.MethodWriter.visitMaxs(MethodWriter.java:1548)
at org.objectweb.asm.MethodVisitor.visitMaxs(MethodVisitor.java:787)
at org.objectweb.asm.tree.MethodNode.accept(MethodNode.java:767)
at org.objectweb.asm.tree.MethodNode.accept(MethodNode.java:647)
at org.objectweb.asm.tree.ClassNode.accept(ClassNode.java:468)
at org.robolectric.internal.bytecode.ClassInstrumentor.instrumentToBytes(ClassInstrumentor.java:132)
at org.robolectric.internal.bytecode.ClassInstrumentor.lambda$instrument$1(ClassInstrumentor.java:147)
at org.robolectric.util.PerfStatsCollector.measure(PerfStatsCollector.java:52)
at org.robolectric.internal.bytecode.ClassInstrumentor.instrument(ClassInstrumentor.java:147)
at org.robolectric.internal.bytecode.SandboxClassLoader.maybeInstrumentClass(SandboxClassLoader.java:172)
at org.robolectric.internal.bytecode.SandboxClassLoader.lambda$loadClass$0(SandboxClassLoader.java:155)
at org.robolectric.util.PerfStatsCollector.measure(PerfStatsCollector.java:52)
at org.robolectric.internal.bytecode.SandboxClassLoader.loadClass(SandboxClassLoader.java:155)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:502)
at org.robolectric.Shadows.reset(Shadows.java:2808)
at org.robolectric.android.internal.AndroidTestEnvironment.resetState(AndroidTestEnvironment.java:605)
at org.robolectric.RobolectricTestRunner.lambda$finallyAfterTest$0(RobolectricTestRunner.java:351)
at org.robolectric.util.PerfStatsCollector.measure(PerfStatsCollector.java:83)
at org.robolectric.RobolectricTestRunner.finallyAfterTest(RobolectricTestRunner.java:349)
at org.robolectric.internal.SandboxTestRunner.executeInSandbox(SandboxTestRunner.java:509)
at org.robolectric.internal.SandboxTestRunner.access$900(SandboxTestRunner.java:67)
at org.robolectric.internal.SandboxTestRunner$7.evaluate(SandboxTestRunner.java:442)
at org.junit.runners.BlockJUnit4ClassRunner$1.evaluate(BlockJUnit4ClassRunner.java:100)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:366)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:103)
at org.robolectric.internal.SandboxTestRunner.access$600(SandboxTestRunner.java:67)
at org.robolectric.internal.SandboxTestRunner$6.evaluate(SandboxTestRunner.java:333)
at org.robolectric.internal.SandboxTestRunner$3.evaluate(SandboxTestRunner.java:233)
at org.robolectric.internal.SandboxTestRunner$5.lambda$evaluate$0(SandboxTestRunner.java:317)
at org.robolectric.internal.bytecode.Sandbox.lambda$runOnMainThread$0(Sandbox.java:101)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:330)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1090)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:614)
at java.base/java.lang.Thread.run(Thread.java:1516)
Until a new Robolectric version is released with ASM 9.9+ (https://asm.ow2.io/versions.html), we'll need to pin the asm version ourselves.