Add inputs to gradle bootRepackage task

See gh-1113

spring-boot-samples/spring-boot-sample-web-ui/build.gradle

@@ -25,6 +25,10 @@ apply plugin: 'spring-boot'
 
 mainClassName = "sample.ui.SampleWebUiApplication"
 
+springBoot {
+    classifier = 'exec'
+}
+
 jar {
 	baseName = 'spring-boot-sample-web-ui'
 	version =  '0.0.0'

spring-boot-tools/spring-boot-gradle-plugin/src/main/groovy/org/springframework/boot/gradle/repackage/RepackagePluginFeatures.java

@@ -93,6 +93,7 @@ public class RepackagePluginFeatures implements PluginFeatures {
 				File file = archive.getArchivePath();
 				String classifier = this.task.getClassifier();
 				if (classifier != null) {
+					this.task.getInputs().file(archive);
 					String withClassifer = file.getName();
 					withClassifer = StringUtils.stripFilenameExtension(withClassifer)
 							+ "-" + classifier + "."