fix: use the correct parent ClassLoader on Quarkus

core/core-impl/src/main/java/ai/timefold/solver/core/impl/domain/common/accessor/gizmo/GizmoClassLoader.java

@@ -5,16 +5,25 @@
 
 /**
  * Loads a class if we have the Gizmo-generated bytecode for it,
- * otherwise the current {@link Thread}'s context {@link ClassLoader}.
+ * otherwise uses the current {@link Thread}'s context {@link ClassLoader}.
  * This implementation is thread-safe.
  */
 public final class GizmoClassLoader extends ClassLoader {
 
     private final Map<String, byte[]> classNameToBytecodeMap = new HashMap<>();
 
+    public GizmoClassLoader() {
+        /*
+         * As parent, Gizmo needs to use the same ClassLoader that loaded its own class.
+         * Otherwise, issues will arise in Quarkus with MemberAccessors which were first loaded by Quarkus
+         * and then loaded again by Gizmo, which uses the default parent ClassLoader.
+         */
+        super(GizmoClassLoader.class.getClassLoader());
+    }
+
     @Override
     public String getName() {
-        return "Timefold Gizmo SolutionCloner ClassLoader";
+        return "Timefold Solver Gizmo ClassLoader";
     }
 
     @Override

core/core-impl/src/test/java/ai/timefold/solver/core/impl/domain/common/accessor/MemberAccessorFactoryTest.java

@@ -4,6 +4,7 @@
 import static org.mockito.Mockito.mock;
 
 import java.lang.reflect.Member;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -109,4 +110,11 @@ void shouldUseGeneratedMemberAccessorIfExists() throws NoSuchMethodException {
         assertThat(memberAccessor)
                 .isSameAs(mockMemberAccessor);
     }
+
+    @Test
+    void gizmoUsesCorrectParentClassLoader() {
+        MemberAccessorFactory memberAccessorFactory = new MemberAccessorFactory(Collections.emptyMap());
+        assertThat(memberAccessorFactory.getGizmoClassLoader().getParent())
+                .isSameAs(memberAccessorFactory.getClass().getClassLoader());
+    }
 }

quarkus-integration/quarkus/deployment/src/main/java/ai/timefold/solver/quarkus/deployment/TimefoldProcessor.java

@@ -90,7 +90,7 @@ class TimefoldProcessor {
 
     @BuildStep
     FeatureBuildItem feature() {
-        return new FeatureBuildItem("timefold");
+        return new FeatureBuildItem("timefold-solver");
     }
 
     @BuildStep