Output stacktrace when Gradle samples fails to build

Author: wilkinsona

buildSrc/src/main/groovy/org/springframework/restdocs/build/SampleBuildConfigurer.groovy

@@ -16,12 +16,14 @@
 
 package org.springframework.restdocs.build
 
+import org.gradle.StartParameter
 import org.gradle.api.GradleException
 import org.gradle.api.Project
 import org.gradle.api.Task
 import org.gradle.api.tasks.Exec
 import org.gradle.api.tasks.Copy
 import org.gradle.api.tasks.GradleBuild
+import org.gradle.logging.ShowStacktrace
 
 public class SampleBuildConfigurer {
 
@@ -85,9 +87,12 @@ public class SampleBuildConfigurer {
 Task gradleBuild = project.tasks.create("${name}Gradle", GradleBuild)
 gradleBuild.description = "Builds the ${name} sample with Gradle"
 gradleBuild.group = "Build"
-gradleBuild.dir = this.workingDir
-gradleBuild.tasks = ['clean', 'build']
 gradleBuild.dependsOn dependencies
+StartParameter startParameter = new StartParameter()
+startParameter.showStacktrace = ShowStacktrace.ALWAYS
+startParameter.taskNames = ['clean', 'build']
+startParameter.currentDir = new File(this.workingDir)
+gradleBuild.startParameter = startParameter
 
 gradleBuild.doFirst {
 replaceVersion(new File(this.workingDir, 'build.gradle'),