Index: test/java/org/apache/ivy/ant/IvyInstallTest.java
===================================================================
--- test/java/org/apache/ivy/ant/IvyInstallTest.java	(revision 0)
+++ test/java/org/apache/ivy/ant/IvyInstallTest.java	(revision 0)
@@ -0,0 +1,105 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You 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
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ */
+package org.apache.ivy.ant;
+
+import java.io.File;
+import java.io.IOException;
+
+import junit.framework.TestCase;
+
+import org.apache.ivy.TestHelper;
+import org.apache.ivy.core.IvyPatternHelper;
+import org.apache.tools.ant.BuildException;
+import org.apache.tools.ant.Project;
+import org.apache.tools.ant.taskdefs.Delete;
+
+
+public class IvyInstallTest extends TestCase {
+    private static final String IVY_RETRIEVE_PATTERN = "build/test/lib/[organisation]/[module]/ivy-[revision].xml";
+    private static final String RETRIEVE_PATTERN = "build/test/lib/[conf]/[artifact]-[revision].[type]";
+    private File _cache;
+    private IvyInstall _install;
+    private Project _project;
+
+    protected void setUp() throws Exception {
+        createCache();
+        cleanTestLib();
+        _project = new Project();
+        _project.setProperty("ivy.settings.file", "test/repositories/ivysettings.xml");
+
+        _install = new IvyInstall();
+        _install.setProject(_project);
+        _install.setCache(_cache);
+    }
+
+    private void createCache() {
+        _cache = new File("build/cache");
+        _cache.mkdirs();
+    }
+
+    protected void tearDown() throws Exception {
+        cleanCache();
+        cleanTestLib();
+    }
+
+    private void cleanCache() {
+        Delete del = new Delete();
+        del.setProject(new Project());
+        del.setDir(_cache);
+        del.execute();
+    }
+
+    private void cleanTestLib() {
+        Delete del = new Delete();
+        del.setProject(new Project());
+        del.setDir(new File("build/test/lib"));
+        del.execute();
+    }
+
+    public void testDependencyNotFoundFailure() {
+        _install.setOrganisation("xxx");
+        _install.setModule("yyy");
+        _install.setRevision("zzz");
+        _install.setFrom("test");
+        _install.setTo("1");
+        
+        try {
+            _install.execute();
+            fail("unknown dependency, failure expected (haltunresolved=true)");
+        } catch (BuildException be) {
+            // success
+            be.printStackTrace();
+        }  
+    }
+
+    public void testDependencyNotFoundSuccess() {
+        _install.setOrganisation("xxx");
+        _install.setModule("yyy");
+        _install.setRevision("zzz");
+        _install.setFrom("test");
+        _install.setTo("1");
+        _install.setHaltonunresolved(false);
+        
+        try {
+            _install.execute();
+        } catch (BuildException be) {
+            be.printStackTrace();
+            fail("unknown dependency, failure unexepected (haltunresolved=false)");
+        }  
+    }
+}
Index: src/java/org/apache/ivy/ant/IvyInstall.java
===================================================================
--- src/java/org/apache/ivy/ant/IvyInstall.java	(revision 531541)
+++ src/java/org/apache/ivy/ant/IvyInstall.java	(working copy)
@@ -25,12 +25,13 @@
 import org.apache.ivy.plugins.matcher.PatternMatcher;
 import org.apache.ivy.util.filter.FilterHelper;
 import org.apache.tools.ant.BuildException;
+import org.apache.ivy.core.report.ResolveReport;
+import org.apache.tools.ant.BuildException;
 
-
 /**
  * Allow to install a module or a set of module from repository to another one.
- * 
- * 
+ *
+ *
  * @author Xavier Hanin
  *
  */
@@ -38,13 +39,14 @@
     private String  _organisation;
     private String  _module;
     private String  _revision;
-    private File 	_cache; 
+    private File 	_cache;
     private boolean _overwrite = false;
     private String _from;
     private String _to;
     private boolean _transitive;
     private String _type;
     private String _matcher = PatternMatcher.EXACT;
+    private boolean _haltOnUnresolved = true;
     
     public void execute() throws BuildException {
         Ivy ivy = getIvyInstance();
@@ -58,12 +60,12 @@
         if (_module == null && PatternMatcher.EXACT.equals(_matcher)) {
             throw new BuildException("no module name provided for ivy publish task: It can either be set explicitely via the attribute 'module' or via 'ivy.module' property or a prior call to <resolve/>");
         } else if (_module == null && !PatternMatcher.EXACT.equals(_matcher)) {
-        	_module = PatternMatcher.ANY_EXPRESSION;
+            _module = PatternMatcher.ANY_EXPRESSION;
         }
         if (_revision == null && PatternMatcher.EXACT.equals(_matcher)) {
             throw new BuildException("no module revision provided for ivy publish task: It can either be set explicitely via the attribute 'revision' or via 'ivy.revision' property or a prior call to <resolve/>");
         } else if (_revision == null && !PatternMatcher.EXACT.equals(_matcher)) {
-        	_revision = PatternMatcher.ANY_EXPRESSION;
+            _revision = PatternMatcher.ANY_EXPRESSION;
         }
         if (_from == null) {
             throw new BuildException("no from resolver name: please provide it through parameter 'from'");
@@ -72,13 +74,25 @@
             throw new BuildException("no to resolver name: please provide it through parameter 'to'");
         }
         ModuleRevisionId mrid = ModuleRevisionId.newInstance(_organisation, _module, _revision);
+        ResolveReport report;
         try {
-            ivy.install(mrid, _from, _to, _transitive, doValidate(settings), _overwrite, FilterHelper.getArtifactTypeFilter(_type), _cache, _matcher);
+            report = ivy.install(mrid, _from, _to, _transitive, doValidate(settings), _overwrite, FilterHelper.getArtifactTypeFilter(_type), _cache, _matcher);
         } catch (Exception e) {
             throw new BuildException("impossible to install "+ mrid +": "+e, e);
         }
+        
+        if (report.getUnresolvedDependencies().length > 0 && isHaltonunresolved()) {
+            throw new BuildException("could not resolve dependencies - see output for details");
+        }
     }
-
+    
+    public boolean isHaltonunresolved() {
+        return _haltOnUnresolved;
+    }
+    public void setHaltonunresolved(boolean haltOnUnresolved) {
+        _haltOnUnresolved = haltOnUnresolved;
+    }
+    
     public File getCache() {
         return _cache;
     }
@@ -134,11 +148,11 @@
     public void setType(String type) {
         _type = type;
     }
-
+    
     public String getMatcher() {
         return _matcher;
     }
-
+    
     public void setMatcher(String matcher) {
         _matcher = matcher;
     }
Index: doc/doc/use/install.html
===================================================================
--- doc/doc/use/install.html	(revision 531541)
+++ doc/doc/use/install.html	(working copy)
@@ -56,6 +56,8 @@
         <td>No, defaults to false</td></tr>
     <tr><td>matcher</td><td>the name of the matcher to use to find the modules to install</td>
         <td>No, defaults to exact</td></tr>
+    <tr><td>haltonunresolved</td><td>true to fail build on unresolved dependencies</td>
+        <td>No, defaults to true</td></tr>
 </tbody>
 </table>
 <h1>Examples</h1>