diff --git a/stf.build/include/top.xml b/stf.build/include/top.xml
index 069978e..eca9ba4 100644
--- a/stf.build/include/top.xml
+++ b/stf.build/include/top.xml
@@ -5,7 +5,7 @@ Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at
 
-     http://www.apache.org/licenses/LICENSE-2.0
+	 http://www.apache.org/licenses/LICENSE-2.0
 
 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
@@ -19,14 +19,18 @@ limitations under the License.
 	<!-- Set a property for accessing environment variables.  -->
 	<property environment="env"/>
 
+	<condition property="system_lib_dir" value="${env.SYSTEM_LIB_DIR}" else="${source_root}/../../systemtest_prereqs">
+    	<isset property="env.SYSTEM_LIB_DIR"/>
+	</condition>
+
+	<echo message="System Library Directory: ${system_lib_dir}"/>
 	<!-- Set default prereqs_root.  -->
 	<!-- If source has been checked out to /home/user/git/stf, default location for prereqs is /home/user/systemtest_prereqs.  -->
-	<property name="prereqs_root" location="${source_root}/../../systemtest_prereqs"/>
+	<property name="prereqs_root" location="${system_lib_dir}"/>
 
 	<!-- Test specific prereqs may have been added to prereqs-root (in path1;path2;path3 notation).
-	     Here the property first_prereqs_root is set containing just the first path in prereqs_root
-	     which is assumed to be where the make configure prereqs are installed. -->
-	<property name="prereqs_root" location="${source_root}/../../systemtest_prereqs"/>
+		 Here the property first_prereqs_root is set containing just the first path in prereqs_root
+		 which is assumed to be where the make configure prereqs are installed. -->
 	<loadresource property="first_prereqs_root" encoding="UTF-8">
 		<concat>${prereqs_root}</concat>
 		<filterchain>
@@ -37,7 +41,7 @@ limitations under the License.
 	<!-- Platform dependent settings.  -->
 	<condition property="exe_suffix" value=".exe" else="" >
 	   <os family="windows" />
-    </condition>
+	</condition>
 	<condition property="is_windows" value="true" else="false" >
 		<os family="windows" />
 	</condition>
@@ -182,7 +186,7 @@ limitations under the License.
 		<property name="ant_dir" location="${first_prereqs_root}/apache-ant"/>
 		<property name="ant_file" value="lib/ant-launcher.jar"/>
 		<property name="ant" location="${ant_dir}/${ant_file}"/>
-	    <available file="${ant}" property="ant_available"/>
+		<available file="${ant}" property="ant_available"/>
 	</target>
 
 	<!--
@@ -195,7 +199,7 @@ limitations under the License.
 		<unzip src="${java.io.tmpdir}/apache-ant/apache-ant-bin.zip" dest="${java.io.tmpdir}/apache-ant"/>
 		<copydir src="${java.io.tmpdir}/apache-ant/apache-ant-${ant-version}" dest="${first_prereqs_root}/apache-ant"/>
 		<delete dir="${java.io.tmpdir}/apache-ant"/>
-	    <available file="${ant}" property="ant_available"/>
+		<available file="${ant}" property="ant_available"/>
 	</target>
 
 	<!-- Target to check if junit is available. -->
@@ -271,7 +275,7 @@ limitations under the License.
 	<target name="check-for-windows-sysinternals" unless="check_prereqs_run">
 		<property name="windows_sysinternals_dir" location="${first_prereqs_root}/windows_sysinternals"/>
 		<!-- We're just using the existence of pskill.exe to determine whether the tools are installed. -->
-	    <available file="${windows_sysinternals_dir}/pskill.exe" property="windows_sysinternals_available"/>
+		<available file="${windows_sysinternals_dir}/pskill.exe" property="windows_sysinternals_available"/>
 	</target>
 
 	<target name="set-download-windows-sysinternals-required">
@@ -282,7 +286,7 @@ limitations under the License.
 					<isset property="windows_sysinternals_available"/>
 				</not>
 			</and>
-	    </condition>
+		</condition>
 	</target>
 	<!--
 		Get the windows sysinternals tools from https://download.sysinternals.com/files/SysinternalsSuite.zip
@@ -293,7 +297,7 @@ limitations under the License.
 		<unzip src="${java.io.tmpdir}/windows_sysinternals/SysinternalsSuite.zip" dest="${windows_sysinternals_dir}"/>
 		<delete dir="${java.io.tmpdir}/windows_sysinternals"/>
 		<!-- We're just using the existence of pskill.exe to determine whether the tools are installed. -->
-	    <available file="${windows_sysinternals_dir}/pskill.exe" property="windows_sysinternals_available"/>
+		<available file="${windows_sysinternals_dir}/pskill.exe" property="windows_sysinternals_available"/>
 	</target>
 	<!--
 		Target to check if there is a tools.jar already copied to PREREQS_ROOT/tools.
@@ -317,7 +321,7 @@ limitations under the License.
 				</and>
 			</or>
 		</condition>
-	    <available file="${tools_jar_dir}/${tools_jar_file}" property="tools_jar" value="${tools_jar_dir}/${tools_jar_file}"/>
+		<available file="${tools_jar_dir}/${tools_jar_file}" property="tools_jar" value="${tools_jar_dir}/${tools_jar_file}"/>
 	</target>
 
 	<!--
@@ -361,10 +365,10 @@ limitations under the License.
 	</condition>
 
 	<condition property="MAKE" value="gmake" else="make">
-	    <or>
-	        <equals arg1="${os.name}" arg2="AIX"/>
-	        <contains string="${os.name}" substring="BSD"/>
-	    </or>
+		<or>
+			<equals arg1="${os.name}" arg2="AIX"/>
+			<contains string="${os.name}" substring="BSD"/>
+		</or>
 	</condition>
 
 	<macrodef name="download-file" description="Use curl to download a file">
@@ -456,7 +460,7 @@ limitations under the License.
 					<isset property="windows_sysinternals_available"/>
 				</not>
 			</and>
-	    </condition>
+		</condition>
 	</target>
 
 	<target name="really-print-windows-sysinternals-error" if="${print_windows_sysinternals_error_required}">