fix: change exception logging when running in maven

sdk-extensions/autoconfigure/src/main/java/io/opentelemetry/sdk/autoconfigure/AutoConfiguredOpenTelemetrySdkBuilder.java

@@ -649,8 +649,18 @@ private ConfigProperties computeConfigProperties() {
   }
 
   // Visible for testing
+  @SuppressWarnings("SystemOut")
   Thread shutdownHook(OpenTelemetrySdk sdk) {
-    return new Thread(sdk::close);
+    return new Thread(
+        () -> {
+          try {
+            sdk.close();
+          } catch (Throwable e) {
+            // https://github.com/open-telemetry/opentelemetry-java/issues/6827
+            // logging deps might not be on the classpath at this point
+            System.out.printf("%s Flush failed during shutdown: %s%n", Level.WARNING, e);
+          }
+        });
   }
 
   private static <I, O1, O2> BiFunction<I, ConfigProperties, O2> mergeCustomizer(

sdk-extensions/autoconfigure/src/test/java/io/opentelemetry/sdk/autoconfigure/AutoConfiguredOpenTelemetrySdkTest.java

@@ -10,6 +10,7 @@
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatCode;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.jupiter.api.Assertions.fail;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.doThrow;
@@ -445,6 +446,22 @@ void builder_callAutoConfigureListeners() {
     verify(listener).afterAutoConfigure(sdk);
   }
 
+  @Test
+  void builder_catchesException() throws InterruptedException {
+    OpenTelemetrySdk sdk = mock(OpenTelemetrySdk.class);
+    doThrow(NoClassDefFoundError.class).when(sdk).close();
+
+    try {
+      Thread thread = builder.shutdownHook(sdk);
+      thread.start();
+      thread.join();
+    } catch (NoClassDefFoundError e) {
+      fail("shutdownHook threw unexpected NoClassDefFoundError", e);
+    }
+
+    verify(sdk).close();
+  }
+
   private static Supplier<Map<String, String>> disableExportPropertySupplier() {
     Map<String, String> props = new HashMap<>();
     props.put("otel.metrics.exporter", "none");