diff --git a/src/r8/r8.targets b/src/r8/r8.targets
index fff9a42d62e..5d4c7d0abd1 100644
--- a/src/r8/r8.targets
+++ b/src/r8/r8.targets
@@ -5,7 +5,7 @@
 
   <PropertyGroup>
     <!--NOTE: we don't want a gradle daemon locking directories on Windows-->
-    <_GradleArgs>--no-daemon</_GradleArgs>
+    <_GradleArgs>--stacktrace --no-daemon</_GradleArgs>
     <BuildDependsOn>
       ResolveReferences;
       _BuildR8;
diff --git a/tests/CodeGen-Binding/Xamarin.Android.LibraryProjectZip-LibBinding/Xamarin.Android.LibraryProjectZip-LibBinding.targets b/tests/CodeGen-Binding/Xamarin.Android.LibraryProjectZip-LibBinding/Xamarin.Android.LibraryProjectZip-LibBinding.targets
index 41684fc8429..af15fcf79ab 100644
--- a/tests/CodeGen-Binding/Xamarin.Android.LibraryProjectZip-LibBinding/Xamarin.Android.LibraryProjectZip-LibBinding.targets
+++ b/tests/CodeGen-Binding/Xamarin.Android.LibraryProjectZip-LibBinding/Xamarin.Android.LibraryProjectZip-LibBinding.targets
@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <UsingTask AssemblyFile="..\..\..\bin\Build$(Configuration)\xa-prep-tasks.dll" TaskName="Xamarin.Android.BuildTools.PrepTasks.ReplaceFileContents" />
   <Target Name="BuildNativeLibs"
       DependsOnTargets="AndroidPrepareForBuild"
       Inputs="jni\simple-lib.c;jni\Android.mk"
@@ -38,15 +39,24 @@
         WorkingDirectory="$(OutputPath)\native-lib-2"
     />
   </Target>
+  <Target Name="_ReplaceGradleFile"
+      Inputs="java\JavaLib\library\build.gradle.in"
+      Outputs="java\JavaLib\library\build.gradle">
+    <ReplaceFileContents
+        SourceFile="java\JavaLib\library\build.gradle.in"
+        DestinationFile="java\JavaLib\library\build.gradle"
+        Replacements="@BUILD_TOOLS_VERSION@=$(XABuildToolsFolder)"
+    />
+  </Target>
   <Target Name="BuildJavaLibs"
-      DependsOnTargets="AndroidPrepareForBuild"
-      Inputs="java\JavaLib\project.properties"
+      DependsOnTargets="AndroidPrepareForBuild;_ReplaceGradleFile"
+      Inputs="java\JavaLib\project.properties;java\JavaLib\library\build.gradle"
       Outputs="$(OutputPath)JavaLib.zip">
     <PropertyGroup>
       <_Jdk9Modules Condition="$(_JdkVersion.StartsWith ('9'))">JAVA_OPTS="--add-modules java.xml.bind"</_Jdk9Modules>
     </PropertyGroup>
     <Exec
-        EnvironmentVariables="ANDROID_HOME=$(AndroidSdkDirectory);JAVA_HOME=$(JavaSdkDirectory)"
+        EnvironmentVariables="ANDROID_HOME=$(AndroidSdkDirectory);ANDROID_NDK_HOME=$(AndroidNdkDirectory);JAVA_HOME=$(JavaSdkDirectory)"
         Command="$(_Jdk9Modules) .\gradlew assembleDebug --stacktrace --no-daemon"
         WorkingDirectory="$(MSBuildThisFileDirectory)java\JavaLib"
     />
diff --git a/tests/CodeGen-Binding/Xamarin.Android.LibraryProjectZip-LibBinding/java/JavaLib/library/.gitignore b/tests/CodeGen-Binding/Xamarin.Android.LibraryProjectZip-LibBinding/java/JavaLib/library/.gitignore
index 796b96d1c40..2498defbaf7 100644
--- a/tests/CodeGen-Binding/Xamarin.Android.LibraryProjectZip-LibBinding/java/JavaLib/library/.gitignore
+++ b/tests/CodeGen-Binding/Xamarin.Android.LibraryProjectZip-LibBinding/java/JavaLib/library/.gitignore
@@ -1 +1,3 @@
 /build
+# Generated
+/build.gradle
\ No newline at end of file
diff --git a/tests/CodeGen-Binding/Xamarin.Android.LibraryProjectZip-LibBinding/java/JavaLib/library/build.gradle b/tests/CodeGen-Binding/Xamarin.Android.LibraryProjectZip-LibBinding/java/JavaLib/library/build.gradle.in
similarity index 92%
rename from tests/CodeGen-Binding/Xamarin.Android.LibraryProjectZip-LibBinding/java/JavaLib/library/build.gradle
rename to tests/CodeGen-Binding/Xamarin.Android.LibraryProjectZip-LibBinding/java/JavaLib/library/build.gradle.in
index 7e19e28a8d2..de12d4af7f5 100644
--- a/tests/CodeGen-Binding/Xamarin.Android.LibraryProjectZip-LibBinding/java/JavaLib/library/build.gradle
+++ b/tests/CodeGen-Binding/Xamarin.Android.LibraryProjectZip-LibBinding/java/JavaLib/library/build.gradle.in
@@ -2,7 +2,7 @@ apply plugin: 'com.android.library'
 
 android {
     compileSdkVersion 25
-    buildToolsVersion "25.0.2"
+    buildToolsVersion "@BUILD_TOOLS_VERSION@"
 
     defaultConfig {
         minSdkVersion 19