Use asm unshadowed and upgrade to 9.4

src/functionalTest/groovy/com/autonomousapps/jvm/JavaToolchainSpec.groovy

@@ -0,0 +1,41 @@
+package com.autonomousapps.jvm
+
+import com.autonomousapps.jvm.projects.JavaToolchainProject
+
+import static com.autonomousapps.utils.Runner.build
+import static com.google.common.truth.Truth.assertThat
+
+final class JavaToolchainSpec extends AbstractJvmSpec {
+
+  def "does not fail with Java #javaToolchainVersion toolchain (#gradleVersion)"() {
+    given: "a Gradle project using Java toolchain version #javaToolchainVersion that has been built"
+    def project = new JavaToolchainProject(javaToolchainVersion)
+    gradleProject = project.gradleProject
+    build(gradleVersion, gradleProject.rootDir, 'build')
+
+    when: 'running buildHealth'
+    def result = build(gradleVersion, gradleProject.rootDir, 'buildHealth')
+
+    then: 'abiAnalysisMain and explodeByteCodeSourceMain tasks were ran'
+    // These two are the ones that were actually failing, sanity check that java library plugin is applied
+    assert result.tasks.any { (it.getPath() == ':proj:abiAnalysisMain') }
+    assert result.tasks.any { (it.getPath() == ':proj:explodeByteCodeSourceMain') }
+
+    and: 'the report should be empty'
+    assertThat(project.actualBuildHealth()).containsExactlyElementsIn(project.expectedBuildHealth)
+
+    where:
+    // Comment out all but the last for speed
+    // See https://docs.gradle.org/8.5/userguide/compatibility.html#java
+    gradleVersion | javaToolchainVersion
+//    GRADLE_7_5    | 18
+//    GRADLE_7_5    | 19
+//    GRADLE_7_6    | 18
+    GRADLE_7_6    | 19
+    // TODO(tsr): some errors running these two scenarios
+//    GRADLE_8_3    | 20
+//    GRADLE_8_5    | 21
+
+    classFileMajorVersion = javaToolchainVersion + 44 // 19 + 44 = 63, is this safe?
+  }
+}

src/functionalTest/groovy/com/autonomousapps/jvm/projects/JavaToolchainProject.groovy

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+package com.autonomousapps.jvm.projects
+
+import com.autonomousapps.AbstractProject
+import com.autonomousapps.kit.GradleProject
+import com.autonomousapps.kit.Source
+import com.autonomousapps.kit.SourceType
+import com.autonomousapps.kit.gradle.Plugin
+import com.autonomousapps.model.ProjectAdvice
+
+import static com.autonomousapps.AdviceHelper.actualProjectAdvice
+import static com.autonomousapps.AdviceHelper.emptyProjectAdviceFor
+import static com.autonomousapps.kit.gradle.Dependency.annotationProcessor
+import static com.autonomousapps.kit.gradle.Dependency.implementation
+
+final class JavaToolchainProject extends AbstractProject {
+
+  final GradleProject gradleProject
+
+  JavaToolchainProject(int javaToolchainVersion) {
+    this.gradleProject = build(javaToolchainVersion)
+  }
+
+  private GradleProject build(int javaToolchainVersion) {
+    return newGradleProjectBuilder()
+      .withSubproject('proj') { s ->
+        s.sources = sources
+        s.withBuildScript { bs ->
+          bs.plugins(Plugin.javaLibrary)
+          bs.dependencies(
+            implementation('org.projectlombok:lombok:1.18.24'),
+            annotationProcessor('org.projectlombok:lombok:1.18.24'),
+          )
+          bs.withGroovy("java { toolchain { languageVersion.set(JavaLanguageVersion.of(${javaToolchainVersion})) } }")
+        }
+      }.write()
+  }
+
+  private List<Source> sources = [
+    new Source(
+      SourceType.JAVA, "Country", "com/example",
+      """\
+      package com.example;
+
+      import lombok.AccessLevel;
+      import lombok.Getter;
+      import lombok.NoArgsConstructor;
+
+      @Getter
+      @NoArgsConstructor(access = AccessLevel.PROTECTED)
+      public class Country {
+        private Long id;
+        private String alpha2;
+        private String alpha3;
+        private String name;
+        private boolean active;
+
+        private Country(final String alpha2, final String alpha3, final String name) {
+          this.alpha2 = alpha2;
+          this.alpha3 = alpha3;
+          this.name = name;
+          this.active = Boolean.TRUE;
+        }
+
+        public static Country of(final String alpha2, final String alpha3, final String name) {
+          return new Country(alpha2, alpha3, name);
+        }
+
+        public void setActive(boolean active) {
+          this.active = active;
+        }
+      }
+      """.stripIndent()
+    )
+  ]
+
+  Set<ProjectAdvice> actualBuildHealth() {
+    return actualProjectAdvice(gradleProject)
+  }
+
+  // In reality we merely hope for unsupported class file major version error
+  final Set<ProjectAdvice> expectedBuildHealth = [
+    emptyProjectAdviceFor(':proj'),
+  ]
+}