<setpermission> requires Ant 1.10+. For the (nightly) build it is not that important.

build.xml

@@ -16,7 +16,7 @@
    See the License for the specific language governing permissions and
    limitations under the License.
 -->
-<project name="apache-ant" default="main" basedir=".">
+<project name="apache-ant" default="main" basedir="." xmlns:if="ant:if">
 
   <!-- Give user a chance to override without editing this file
        (and without typing -D on each invocation) -->
@@ -100,6 +100,7 @@
        ===================================================================
   -->
   <property name="debug" value="true"/>
+  <antversion property="ant1.10+" atleast="1.10"/>
   <property name="setpermissions.fail" value="true"/>
   <property name="deprecation" value="false"/>
   <property name="optimize" value="true"/>
@@ -121,7 +122,6 @@
   <property name="junit.collector.dir" value="${build.dir}/failingTests"/>
   <property name="junit.collector.class" value="FailedTests"/>
 
-
   <!--
        ===================================================================
          Set the paths used in the build
@@ -913,13 +913,13 @@
       <include name="*.pl"/>
     </fixcrlf>
 
-    <setpermissions mode="755" failonerror="${setpermissions.fail}">
+    <setpermissions mode="755" failonerror="${setpermissions.fail}" if:set="ant1.10+">
       <dirset dir="${dist.dir}"/>
     </setpermissions>
-    <setpermissions mode="644" failonerror="${setpermissions.fail}">
+    <setpermissions mode="644" failonerror="${setpermissions.fail}" if:set="ant1.10+">
       <fileset dir="${dist.dir}"/>
     </setpermissions>
-    <setpermissions mode="755" failonerror="${setpermissions.fail}">
+    <setpermissions mode="755" failonerror="${setpermissions.fail}" if:set="ant1.10+">
       <fileset dir="${dist.bin}">
         <include name="**/ant"/>
         <include name="**/antRun"/>
@@ -1027,13 +1027,13 @@
       </fileset>
     </copy>
 
-    <setpermissions mode="755" failonerror="${setpermissions.fail}">
+    <setpermissions mode="755" failonerror="${setpermissions.fail}" if:set="ant1.10+">
       <dirset dir="${dist.dir}"/>
     </setpermissions>
-    <setpermissions mode="644" failonerror="${setpermissions.fail}">
+    <setpermissions mode="644" failonerror="${setpermissions.fail}" if:set="ant1.10+">
       <fileset dir="${dist.dir}"/>
     </setpermissions>
-    <setpermissions mode="755" failonerror="${setpermissions.fail}">
+    <setpermissions mode="755" failonerror="${setpermissions.fail}" if:set="ant1.10+">
       <fileset dir="${dist.bin}">
         <include name="**/ant"/>
         <include name="**/antRun"/>
@@ -1147,13 +1147,13 @@
       <exclude name="${tests.etc.dir}/taskdefs/fixcrlf/input/Junk?.java"/>
     </fixcrlf>
 
-    <setpermissions mode="755" failonerror="${setpermissions.fail}">
+    <setpermissions mode="755" failonerror="${setpermissions.fail}" if:set="ant1.10+">
       <dirset dir="${src.dist.dir}"/>
     </setpermissions>
-    <setpermissions mode="644" failonerror="${setpermissions.fail}">
+    <setpermissions mode="644" failonerror="${setpermissions.fail}" if:set="ant1.10+">
       <fileset dir="${src.dist.dir}"/>
     </setpermissions>
-    <setpermissions mode="755" failonerror="${setpermissions.fail}">
+    <setpermissions mode="755" failonerror="${setpermissions.fail}" if:set="ant1.10+">
       <fileset dir="${src.dist.dir}">
         <include name="**/*.sh"/>
         <include name="**/*.pl"/>