Merge pull request #5512 from rob-baily/issues-5465

* pr/5512:
  Polish contribution
  Add check for non empty list of factories

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/EnableAutoConfigurationImportSelector.java

@@ -140,8 +140,12 @@ public class EnableAutoConfigurationImportSelector
 	 */
 	protected List<String> getCandidateConfigurations(AnnotationMetadata metadata,
 			AnnotationAttributes attributes) {
-		return SpringFactoriesLoader.loadFactoryNames(
+		List<String> configurations = SpringFactoriesLoader.loadFactoryNames(
 				getSpringFactoriesLoaderFactoryClass(), getBeanClassLoader());
+		Assert.notEmpty(configurations,
+				"No auto configuration classes found in META-INF/spring.factories. If you" +
+						"are using a custom packaging, make sure that file is correct.");
+		return configurations;
 	}
 
 	/**