try to make ant create the "missing" folder
diff --git a/development/org.eclipse.wst.sse.sieditor.repository/pom.xml b/development/org.eclipse.wst.sse.sieditor.repository/pom.xml
index d6af739..a3525f6 100644
--- a/development/org.eclipse.wst.sse.sieditor.repository/pom.xml
+++ b/development/org.eclipse.wst.sse.sieditor.repository/pom.xml
@@ -52,6 +52,7 @@
 								</goals>
 								<configuration>
 									<tasks>
+										<mkdir dir="${snapshotRepository}"/>
 										<delete includeemptydirs="false">
 											<fileset dir="${snapshotRepository}">
 												<include name="**" />