[FIXED JENKINS-12995] specify absolute path of build script.

src/main/java/hudson/plugins/phing/PhingBuilder.java

@@ -157,7 +157,7 @@ public boolean perform(AbstractBuild<?, ?> build, Launcher launcher, BuildListen
             return false;
         }
 
-        args.add("-buildfile", buildScript.getName());
+        args.add("-buildfile", buildScript.getRemote());
 
         // Targets
         String expandedTargets = Util.replaceMacro(env.expand(targets), vr);
@@ -185,7 +185,8 @@ public boolean perform(AbstractBuild<?, ?> build, Launcher launcher, BuildListen
         // Working Directory
         // since 0.9
         FilePath working = useModuleRoot ? build.getModuleRoot() : buildScript.getParent();
-
+        listener.getLogger().println(Messages.Phing_WorkingDirectory(working));
+
         final long startTime = System.currentTimeMillis();
         try {
             PhingConsoleAnnotator pca = new PhingConsoleAnnotator(listener.getLogger(), build.getCharset());

src/main/resources/hudson/plugins/phing/Messages.properties

@@ -8,3 +8,4 @@ Phing.ProjectConfigNeeded = Maybe you need to configure the job to choose one of
 Phing.NotAPHPCommand = {0} doesn''t exists.
 Phing.DirectoryNotAllowed = {0} seems to be directory.
 Phing.NotFoundABuildScript = buildfile ''{0}'' not found.
+Phing.WorkingDirectory = use ''{0}'' as a working directory. 

src/main/resources/hudson/plugins/phing/Messages_ja.properties

@@ -8,3 +8,4 @@ Phing.ProjectConfigNeeded = \u30a4\u30f3\u30b9\u30c8\u30fc\u30eb\u3057\u305fPhin
 Phing.NotAPHPCommand = {0}\u304c\u5b58\u5728\u3057\u307e\u305b\u3093\u3002
 Phing.DirectoryNotAllowed= {0} \u306f\u30c7\u30a3\u30ec\u30af\u30c8\u30ea\u3067\u3059\u3002
 Phing.NotFoundABuildScript = \u30d3\u30eb\u30c9\u30d5\u30a1\u30a4\u30eb''{0}''\u304c\u5b58\u5728\u3057\u307e\u305b\u3093\u3002
+Phing.WorkingDirectory = ''{0}'' \u3092\u30ef\u30fc\u30ad\u30f3\u30b0\u30c7\u30a3\u30ec\u30af\u30c8\u30ea\u3068\u3057\u3066\u4f7f\u7528\u3057\u307e\u3059\u3002 

src/main/resources/hudson/plugins/phing/PhingBuilder/config.jelly

@@ -24,7 +24,7 @@
         </f:entry>
         <f:entry title="">
             <label>
-              <f:checkbox name="phingBuilder.useModuleRoot" checked="${instance.useModuleRoot}" />
+              <f:checkbox name="phingBuilder.useModuleRoot" default="true" checked="${instance.useModuleRoot}" />
               ${%Use ModuleRoot as working directory}
             </label>
         </f:entry>