Index: extra-targets.xml
===================================================================
--- extra-targets.xml	(revision 1555925)
+++ extra-targets.xml	(working copy)
@@ -105,7 +105,10 @@
     <groovy taskname="svn" classpathref="svnkit.classpath"><![CDATA[
       import org.tmatesoft.svn.core.*;
       import org.tmatesoft.svn.core.wc.*;
+      import org.apache.tools.ant.Project;
       
+      def RECOMMENDED_SVNKIT_18 = '1.8.2';
+      
       SVNClientManager manager = SVNClientManager.newInstance();
       SVNStatusClient statusClient = manager.getStatusClient();
       SVNWCClient wcClient = manager.getWCClient();
@@ -115,6 +118,24 @@
       def convertRelative = {
         file -> '.' + file.getAbsolutePath().substring(baseLen).replace(File.separatorChar, (char)'/');
       }
+
+      // do some fake check, to verify if this is valid SVN working copy. If this fails ignore checks but log some useful message.
+      try {
+        statusClient.doStatus(basedir, false);
+      } catch (SVNException ex) {
+        int code = ex.getErrorMessage().getErrorCode().getCode();
+        if (code == SVNErrorCode.WC_UNSUPPORTED_FORMAT.getCode()) {
+          task.log('WARNING: Unsupported SVN working copy version! Disabling checks...', Project.MSG_WARN);
+          task.log('If your working copy is on version 1.8 already, please pass -Dsvnkit.version=' + RECOMMENDED_SVNKIT_18 + ' to successfully run checks.', Project.MSG_INFO);
+          return;
+        } else if (code == SVNErrorCode.WC_NOT_DIRECTORY.getCode() || code == SVNErrorCode.WC_NOT_FILE.getCode()) {
+          task.log('WARNING: Development directory is not an SVN checkout! Disabling checks...', Project.MSG_WARN);
+          return;
+        } else {
+          task.log('WARNING: Development directory is not a valid SVN checkout (' + ex.getErrorMessage() + '). Disabling checks...', Project.MSG_WARN);
+          return;
+        }
+      }
       
       Set missingProps = new TreeSet(), unversioned = new TreeSet(), changed = new TreeSet();