Find antcontrib

build.xml

 <project name="MQTT C Client" default="full">
 
-  <!-- taskdef resource="net/sf/antcontrib/antlib.xml"/ -->
-
-  <property name="output.folder" value="build/output" /> 
+  <taskdef resource="net/sf/antcontrib/antlib.xml">
+    <classpath>
+      <pathelement path="${classpath}" />
+      <pathelement location="${relengCommonBuilderDir}/lib/ant-contrib.jar" />
+      <pathelement location="${relengBuilderDir}/lib/ant-contrib.jar" />
+      <pathelement location="${thirdPartyJarsDir}/ant-contrib.jar" />
+      <pathelement location="/usr/share/java/ant-contrib.jar" />
+    </classpath>
+  </taskdef>
+
+  <property name="output.folder" value="${WORKSPACE}/build" /> 
   <property name="release.version" value="1.0.0.2" />
 
   <property name="libname" value="mqttv3c" />
@@ -11,7 +19,9 @@
   <property name="libname.async.ssl" value="mqttv3as" />
 	
   <target name="init">
-    <tstamp/>
+    <tstamp>
+      <format property="buildTimestamp" pattern="yyyyMMddHHmm" />
+    </tstamp>
 
     <fileset id="sync.source.fileset" dir="src">
       <include name="*.c"/>