[MNG-4186] Provide an exact pointer to documentation specific to each known exception that can occur

git-svn-id: https://svn.apache.org/repos/asf/maven/maven-3/trunk@827792 13f79535-47bb-0310-9956-ffa450edef68

maven-compat/src/main/java/org/apache/maven/artifact/resolver/AbstractArtifactResolutionException.java

@@ -196,6 +196,9 @@ private static String constructMessageBase( String message,
         StringBuilder sb = new StringBuilder();
 
         sb.append( message );
+
+        if ( message == null || !message.contains( "from the specified remote repositories:" ) )
+        {
             sb.append( LS );
             sb.append( "  " + groupId + ":" + artifactId + ":" + type + ":" + version );
             sb.append( LS );
@@ -240,6 +243,8 @@ private static String constructMessageBase( String message,
 
             sb.append( constructArtifactPath( path, "" ) );
             sb.append( LS );
+        }
+
         return sb.toString();
     }
 

maven-compat/src/main/java/org/apache/maven/repository/LocalRepositoryNotAccessibleException.java

@@ -0,0 +1,44 @@
+package org.apache.maven.repository;
+
+/*
+ * 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.
+ */
+
+import java.io.IOException;
+
+/**
+ * Signals a failure to store files within the local repository.
+ * 
+ * @author Benjamin Bentmann
+ */
+public class LocalRepositoryNotAccessibleException
+    extends IOException
+{
+
+    public LocalRepositoryNotAccessibleException( String message, Throwable cause )
+    {
+        super( message );
+        initCause( cause );
+    }
+
+    public LocalRepositoryNotAccessibleException( String message )
+    {
+        super( message );
+    }
+
+}

maven-compat/src/main/java/org/apache/maven/repository/legacy/DefaultWagonManager.java

@@ -122,6 +122,8 @@ else if ( !artifact.getFile().exists() )
     public void getArtifact( Artifact artifact, List<ArtifactRepository> remoteRepositories, TransferListener downloadMonitor, boolean force )
         throws TransferFailedException, ResourceDoesNotExistException
     {
+        TransferFailedException tfe = null;
+
         for ( ArtifactRepository repository : remoteRepositories )
         {
             try
@@ -139,20 +141,31 @@ public void getArtifact( Artifact artifact, List<ArtifactRepository> remoteRepos
                 // This one we will eat when looking through remote repositories
                 // because we want to cycle through them all before squawking.
 
-                logger.debug( "Unable to find resource '" + artifact.getId() + "' in repository " + repository.getId() + " (" + repository.getUrl() + ")", e );
+                logger.debug( "Unable to find resource '" + artifact.getId() + "' in repository " + repository.getId()
+                    + " (" + repository.getUrl() + ")", e );
             }
             catch ( TransferFailedException e )
             {
-                logger.debug( "Unable to get resource '" + artifact.getId() + "' from repository " + repository.getId() + " (" + repository.getUrl() + ")", e );
+                tfe = e;
+
+                logger.debug( "Unable to get resource '" + artifact.getId() + "' from repository " + repository.getId()
+                    + " (" + repository.getUrl() + ")", e );
             }
         }
 
         // if it already exists locally we were just trying to force it - ignore the update
         if ( !artifact.getFile().exists() )
+        {
+            if ( tfe != null )
+            {
+                throw tfe;
+            }
+            else
             {
                 throw new ResourceDoesNotExistException( "Unable to download the artifact from any repository" );
             }
         }
+    }
 
     public void getArtifactMetadata( ArtifactMetadata metadata, ArtifactRepository repository, File destination, String checksumPolicy )
         throws TransferFailedException, ResourceDoesNotExistException

maven-core/src/main/java/org/apache/maven/DefaultMaven.java

@@ -29,9 +29,6 @@
 import java.util.Map;
 
 import org.apache.maven.artifact.ArtifactUtils;
-import org.apache.maven.exception.DefaultExceptionHandler;
-import org.apache.maven.exception.ExceptionHandler;
-import org.apache.maven.exception.ExceptionSummary;
 import org.apache.maven.execution.DefaultLifecycleEvent;
 import org.apache.maven.execution.DefaultMavenExecutionResult;
 import org.apache.maven.execution.DuplicateProjectException;
@@ -50,6 +47,7 @@
 import org.apache.maven.project.ProjectBuildingRequest;
 import org.apache.maven.project.ProjectBuildingResult;
 import org.apache.maven.repository.DelegatingLocalArtifactRepository;
+import org.apache.maven.repository.LocalRepositoryNotAccessibleException;
 import org.codehaus.plexus.PlexusContainer;
 import org.codehaus.plexus.component.annotations.Component;
 import org.codehaus.plexus.component.annotations.Requirement;
@@ -92,14 +90,18 @@ private void fireEvent( MavenSession session, ExecutionEventCatapult catapult )
 
     public MavenExecutionResult execute( MavenExecutionRequest request )
     {
+        MavenExecutionResult result;
+
         try
         {
-            return doExecute( request );
+            result = doExecute( request );
         }
         catch ( OutOfMemoryError e )
         {
-            return processResult( new DefaultMavenExecutionResult(), e );
+            result = processResult( new DefaultMavenExecutionResult(), e );
         }
+
+        return result;
     }
 
     private MavenExecutionResult doExecute( MavenExecutionRequest request )
@@ -114,7 +116,17 @@ private MavenExecutionResult doExecute( MavenExecutionRequest request )
         
         MavenExecutionResult result = new DefaultMavenExecutionResult();
 
-        DelegatingLocalArtifactRepository delegatingLocalArtifactRepository = new DelegatingLocalArtifactRepository( request.getLocalRepository() );
+        try
+        {
+            validateLocalRepository( request );
+        }
+        catch ( LocalRepositoryNotAccessibleException e )
+        {
+            return processResult( result, e );
+        }
+
+        DelegatingLocalArtifactRepository delegatingLocalArtifactRepository =
+            new DelegatingLocalArtifactRepository( request.getLocalRepository() );
         
         request.setLocalRepository( delegatingLocalArtifactRepository );        
 
@@ -229,6 +241,18 @@ private MavenExecutionResult doExecute( MavenExecutionRequest request )
         return result;
     }
 
+    private void validateLocalRepository( MavenExecutionRequest request )
+        throws LocalRepositoryNotAccessibleException
+    {
+        File localRepoDir = request.getLocalRepositoryPath();
+        localRepoDir.mkdirs();
+
+        if ( !localRepoDir.isDirectory() )
+        {
+            throw new LocalRepositoryNotAccessibleException( "Could not create local repository at " + localRepoDir );
+        }
+    }
+
     private Collection<AbstractMavenLifecycleParticipant> getLifecycleParticipants( Collection<MavenProject> projects )
     {
         Collection<AbstractMavenLifecycleParticipant> lifecycleListeners =
@@ -279,17 +303,11 @@ private Collection<AbstractMavenLifecycleParticipant> getLifecycleParticipants(
 
     private MavenExecutionResult processResult( MavenExecutionResult result, Throwable e )
     {
-        ExceptionHandler handler = new DefaultExceptionHandler();
-        
-        ExceptionSummary es = handler.handleException( e );                        
-
         if ( !result.getExceptions().contains( e ) )
         {
             result.addException( e );
         }
 
-        result.setExceptionSummary( es );    
-        
         return result;
     }
     

maven-core/src/main/java/org/apache/maven/exception/DefaultExceptionHandler.java

@@ -19,16 +19,17 @@
  * under the License.
  */
 
-import org.apache.maven.artifact.resolver.ArtifactNotFoundException;
+import java.net.UnknownHostException;
-import org.apache.maven.artifact.resolver.ArtifactResolutionException;
+import java.util.ArrayList;
-import org.apache.maven.plugin.CycleDetectedInPluginGraphException;
+import java.util.List;
+
+import org.apache.maven.model.building.ModelProblem;
+import org.apache.maven.plugin.AbstractMojoExecutionException;
 import org.apache.maven.plugin.MojoExecutionException;
 import org.apache.maven.plugin.MojoFailureException;
-import org.apache.maven.plugin.MojoNotFoundException;
+import org.apache.maven.plugin.PluginExecutionException;
-import org.apache.maven.plugin.PluginDescriptorParsingException;
+import org.apache.maven.project.ProjectBuildingException;
-import org.apache.maven.plugin.PluginNotFoundException;
+import org.apache.maven.project.ProjectBuildingResult;
-import org.apache.maven.plugin.PluginResolutionException;
-import org.apache.maven.plugin.prefix.NoPluginFoundForPrefixException;
 import org.codehaus.plexus.component.annotations.Component;
 import org.codehaus.plexus.util.StringUtils;
 
@@ -79,73 +80,162 @@
 public class DefaultExceptionHandler
     implements ExceptionHandler
 {
+
     public ExceptionSummary handleException( Throwable exception )
     {
-        String message;
+        return handle( "", exception );
-        
-        String reference = "http://";
-        
-        // Plugin problems
-        if ( exception instanceof PluginNotFoundException )
-        {
-            message = exception.getMessage();
-        }
-        else if ( exception instanceof PluginResolutionException )
-        {
-            message = exception.getMessage();           
-        }
-        else if ( exception instanceof PluginDescriptorParsingException )
-        {
-            message = exception.getMessage();           
-        }
-        else if ( exception instanceof CycleDetectedInPluginGraphException )
-        {
-            message = exception.getMessage();           
-        }        
-        else if ( exception instanceof NoPluginFoundForPrefixException )
-        {
-            message = exception.getMessage();                       
     }
 
-        // Project dependency downloading problems.
+    private ExceptionSummary handle( String message, Throwable exception )
-        else if ( exception instanceof ArtifactNotFoundException )
     {
-            message = exception.getMessage();
+        String reference = getReference( exception );
+
+        List<ExceptionSummary> children = null;
+
+        if ( exception instanceof ProjectBuildingException )
+        {
+            List<ProjectBuildingResult> results = ( (ProjectBuildingException) exception ).getResults();
+
+            children = new ArrayList<ExceptionSummary>();
+
+            for ( ProjectBuildingResult result : results )
+            {
+                ExceptionSummary child = handle( result );
+                if ( child != null )
+                {
+                    children.add( child );
                 }
-        else if ( exception instanceof ArtifactResolutionException )
-        {
-            message = exception.getMessage();
             }
 
-        // Mojo problems
+            message = "The build could not read " + children.size() + " project" + ( children.size() == 1 ? "" : "s" );
-        else if ( exception instanceof MojoNotFoundException )
+        }
+        else
         {
-            message = exception.getMessage();            
+            message = getMessage( message, exception );
+        }
+
+        return new ExceptionSummary( exception, message, reference, children );
+    }
+
+    private ExceptionSummary handle( ProjectBuildingResult result )
+    {
+        List<ExceptionSummary> children = new ArrayList<ExceptionSummary>();
+
+        for ( ModelProblem problem : result.getProblems() )
+        {
+            ExceptionSummary child = handle( problem );
+            if ( child != null )
+            {
+                children.add( child );
+            }
+        }
+
+        if ( children.isEmpty() )
+        {
+            return null;
+        }
+
+        String message =
+            "The project " + result.getProjectId() + " (" + result.getPomFile() + ") has " + children.size() + " error"
+                + ( children.size() == 1 ? "" : "s" );
+
+        return new ExceptionSummary( null, message, null, children );
+    }
+
+    private ExceptionSummary handle( ModelProblem problem )
+    {
+        if ( ModelProblem.Severity.ERROR.compareTo( problem.getSeverity() ) >= 0 )
+        {
+            return handle( problem.getMessage(), problem.getException() );
+        }
+        else
+        {
+            return null;
+        }
+    }
+
+    private String getReference( Throwable exception )
+    {
+        String reference = "";
+
+        if ( exception != null )
+        {
+            if ( exception instanceof MojoExecutionException )
+            {
+                reference = MojoExecutionException.class.getSimpleName();
             }
             else if ( exception instanceof MojoFailureException )
             {
-            message = ((MojoFailureException)exception).getLongMessage();
+                reference = MojoFailureException.class.getSimpleName();
-
+            }
-            if ( StringUtils.isEmpty( message ) )
+            else if ( exception instanceof LinkageError )
             {
-                message = exception.getMessage();
+                reference = LinkageError.class.getSimpleName();
+            }
+            else if ( exception instanceof PluginExecutionException )
+            {
+                reference = getReference( exception.getCause() );
+
+                if ( StringUtils.isEmpty( reference ) )
+                {
+                    reference = exception.getClass().getSimpleName();
                 }
             }
-        else if ( exception instanceof MojoExecutionException )
+            else if ( !( exception instanceof RuntimeException ) )
             {
-            message = ((MojoExecutionException)exception).getLongMessage();
+                reference = exception.getClass().getSimpleName();
-
-            if ( StringUtils.isEmpty( message ) )
-            {
-                message = exception.getMessage();
             }
         }
 
-        else
+        if ( StringUtils.isNotEmpty( reference ) && !reference.startsWith( "http:" ) )
         {
-            message = exception.getMessage();
+            reference = "http://cwiki.apache.org/confluence/display/MAVEN/" + reference;
         }
 
-        return new ExceptionSummary( exception, message, reference );
+        return reference;
     }
+
+    private String getMessage( String message, Throwable exception )
+    {
+        String fullMessage = ( message != null ) ? message : "";
+
+        for ( Throwable t = exception; t != null; t = t.getCause() )
+        {
+            String exceptionMessage = t.getMessage();
+
+            if ( t instanceof AbstractMojoExecutionException )
+            {
+                String longMessage = ( (AbstractMojoExecutionException) t ).getLongMessage();
+                if ( StringUtils.isNotEmpty( longMessage ) )
+                {
+                    exceptionMessage = longMessage;
+                }
+            }
+
+            if ( t instanceof UnknownHostException && !fullMessage.contains( "host" ) )
+            {
+                if ( fullMessage.length() > 0 )
+                {
+                    fullMessage += ": ";
+                }
+                fullMessage += "Unknown host " + exceptionMessage;
+            }
+            else if ( !fullMessage.contains( exceptionMessage ) )
+            {
+                if ( fullMessage.length() > 0 )
+                {
+                    fullMessage += ": ";
+                }
+                fullMessage += exceptionMessage;
+            }
+        }
+
+        if ( StringUtils.isEmpty( fullMessage ) && exception != null )
+        {
+            fullMessage = exception.toString();
+        }
+
+        return fullMessage.trim();
+    }
+
 }

maven-core/src/main/java/org/apache/maven/exception/ExceptionSummary.java

@@ -19,6 +19,9 @@
  * under the License.
  */
 
+import java.util.Collections;
+import java.util.List;
+
 // provide a
 // - the exception
 // - useful message
@@ -28,17 +31,26 @@
 
 public class ExceptionSummary
 {
+
     private Throwable exception;
 
     private String message;
 
     private String reference;
 
+    private List<ExceptionSummary> children;
+
     public ExceptionSummary( Throwable exception, String message, String reference )
+    {
+        this( exception, message, reference, null );
+    }
+
+    public ExceptionSummary( Throwable exception, String message, String reference, List<ExceptionSummary> children )
     {
         this.exception = exception;
-        this.message = message;
+        this.message = ( message != null ) ? message : "";
-        this.reference = reference;
+        this.reference = ( reference != null ) ? reference : "";
+        this.children = ( children != null ) ? children : Collections.<ExceptionSummary> emptyList();
     }
 
     public Throwable getException()
@@ -55,4 +67,10 @@ public String getReference()
     {
         return reference;
     }
+
+    public List<ExceptionSummary> getChildren()
+    {
+        return children;
+    }
+
 }

maven-core/src/main/java/org/apache/maven/execution/DefaultMavenExecutionRequest.java

@@ -426,6 +426,11 @@ public MavenExecutionRequest setLocalRepository( ArtifactRepository localReposit
     {
         this.localRepository = localRepository;
 
+        if ( localRepository != null )
+        {
+            setLocalRepositoryPath( new File( localRepository.getBasedir() ).getAbsoluteFile() );
+        }
+
         return this;
     }
 

maven-core/src/main/java/org/apache/maven/execution/DefaultMavenExecutionResult.java

@@ -26,7 +26,6 @@
 import java.util.Map;
 
 import org.apache.maven.artifact.resolver.ArtifactResolutionResult;
-import org.apache.maven.exception.ExceptionSummary;
 import org.apache.maven.project.MavenProject;
 
 /** @author Jason van Zyl */
@@ -41,8 +40,6 @@ public class DefaultMavenExecutionResult
 
     private List<Throwable> exceptions;
 
-    private ExceptionSummary exceptionSummary;
-
     private Map<MavenProject, BuildSummary> buildSummaries;
 
     public MavenExecutionResult setProject( MavenProject project )
@@ -103,18 +100,6 @@ public boolean hasExceptions()
         return !getExceptions().isEmpty();
     }
 
-    public MavenExecutionResult setExceptionSummary( ExceptionSummary exceptionSummary )
-    {
-        this.exceptionSummary = exceptionSummary;
-
-        return this;
-    }
-    
-    public ExceptionSummary getExceptionSummary()
-    {
-        return exceptionSummary;
-    }
-
     public BuildSummary getBuildSummary( MavenProject project )
     {
         return ( buildSummaries != null ) ? buildSummaries.get( project ) : null;

maven-core/src/main/java/org/apache/maven/execution/MavenExecutionResult.java

@@ -50,9 +50,6 @@ public interface MavenExecutionResult
 
     boolean hasExceptions();
 
-    MavenExecutionResult setExceptionSummary( ExceptionSummary exceptionSummary );
-    ExceptionSummary getExceptionSummary();
-
     /**
      * Gets the build summary for the specified project.
      * 

maven-core/src/main/java/org/apache/maven/plugin/BuildPluginManager.java

@@ -36,7 +36,7 @@ MojoDescriptor getMojoDescriptor( Plugin plugin, String goal, RepositoryRequest
         throws PluginNotFoundException, PluginResolutionException, PluginDescriptorParsingException, MojoNotFoundException, InvalidPluginDescriptorException;
 
     ClassRealm getPluginRealm( MavenSession session, PluginDescriptor pluginDescriptor )
-        throws PluginManagerException;
+        throws PluginResolutionException, PluginManagerException;
 
     void executeMojo( MavenSession session, MojoExecution execution )
         throws MojoFailureException, MojoExecutionException, PluginConfigurationException, PluginManagerException;

maven-core/src/main/java/org/apache/maven/plugin/DefaultBuildPluginManager.java

@@ -19,7 +19,6 @@
 import java.io.PrintStream;
 
 import org.apache.maven.artifact.repository.RepositoryRequest;
-import org.apache.maven.artifact.resolver.ArtifactResolutionException;
 import org.apache.maven.execution.MavenSession;
 import org.apache.maven.model.Plugin;
 import org.apache.maven.plugin.descriptor.MojoDescriptor;
@@ -75,7 +74,16 @@ public void executeMojo( MavenSession session, MojoExecution mojoExecution )
 
         Mojo mojo = null;
 
-        ClassRealm pluginRealm = getPluginRealm( session, mojoDescriptor.getPluginDescriptor() );            
+        ClassRealm pluginRealm;
+        try
+        {
+            pluginRealm = getPluginRealm( session, mojoDescriptor.getPluginDescriptor() );
+        }
+        catch ( PluginResolutionException e )
+        {
+            throw new PluginExecutionException( mojoExecution, project, e );
+        }
+
         ClassRealm oldLookupRealm = container.getLookupRealm();
         ClassLoader oldClassLoader = Thread.currentThread().getContextClassLoader();
 
@@ -110,22 +118,36 @@ public void executeMojo( MavenSession session, MojoExecution mojoExecution )
         {
             throw new PluginExecutionException( mojoExecution, project, e );
         }
+        catch ( NoClassDefFoundError e )
+        {
+            ByteArrayOutputStream os = new ByteArrayOutputStream( 1024 );
+            PrintStream ps = new PrintStream( os );
+            ps.println( "A required class was missing while executing " + mojoDescriptor.getId() + ": "
+                + e.getMessage() );
+            pluginRealm.display( ps );
+
+            Exception wrapper = new PluginContainerException( mojoDescriptor, pluginRealm, os.toString(), e );
+
+            throw new PluginExecutionException( mojoExecution, project, wrapper );
+        }
         catch ( LinkageError e )
         {
             ByteArrayOutputStream os = new ByteArrayOutputStream( 1024 );
             PrintStream ps = new PrintStream( os );
-            ps.println( "A linkage error occured while executing " + mojoDescriptor.getId() );
+            ps.println( "An API incompatibility was encountered while executing " + mojoDescriptor.getId() + ": "
-            ps.println( e );
+                + e.getClass().getName() + ": " + e.getMessage() );
             pluginRealm.display( ps );
 
-            throw new PluginExecutionException( mojoExecution, project, os.toString(), e );
+            Exception wrapper = new PluginContainerException( mojoDescriptor, pluginRealm, os.toString(), e );
+
+            throw new PluginExecutionException( mojoExecution, project, wrapper );
         }
         catch ( ClassCastException e )
         {
             ByteArrayOutputStream os = new ByteArrayOutputStream( 1024 );
             PrintStream ps = new PrintStream( os );
-            ps.println( "A type incompatibility occured while executing " + mojoDescriptor.getId() );
+            ps.println( "A type incompatibility occured while executing " + mojoDescriptor.getId() + ": "
-            ps.println( e );
+                + e.getMessage() );
             pluginRealm.display( ps );
 
             throw new PluginExecutionException( mojoExecution, project, os.toString(), e );
@@ -148,10 +170,10 @@ public void executeMojo( MavenSession session, MojoExecution mojoExecution )
     /**
      * TODO pluginDescriptor classRealm and artifacts are set as a side effect of this
      *      call, which is not nice.
-     * @throws ArtifactResolutionException 
+     * @throws PluginResolutionException 
      */
     public ClassRealm getPluginRealm( MavenSession session, PluginDescriptor pluginDescriptor ) 
-        throws PluginManagerException
+        throws PluginResolutionException, PluginManagerException
     {
         ClassRealm pluginRealm = pluginDescriptor.getClassRealm();
         if ( pluginRealm != null )
@@ -159,17 +181,8 @@ public ClassRealm getPluginRealm( MavenSession session, PluginDescriptor pluginD
             return pluginRealm;
         }
 
-        Plugin plugin = pluginDescriptor.getPlugin();
+        mavenPluginManager.setupPluginRealm( pluginDescriptor, session, session.getCurrentProject().getClassRealm(),
-
+                                             null );
-        try
-        {
-            mavenPluginManager.setupPluginRealm( pluginDescriptor, session,
-                                                 session.getCurrentProject().getClassRealm(), null );
-        }
-        catch ( PluginResolutionException e )
-        {
-            throw new PluginManagerException( plugin, e.getMessage(), e );
-        }
 
         return pluginDescriptor.getClassRealm();
     }

maven-core/src/main/java/org/apache/maven/plugin/MavenPluginManager.java

@@ -74,7 +74,7 @@ MojoDescriptor getMojoDescriptor( Plugin plugin, String goal, RepositoryRequest
      */
     void setupPluginRealm( PluginDescriptor pluginDescriptor, MavenSession session, ClassLoader parent,
                            List<String> imports )
-        throws PluginResolutionException, PluginManagerException;
+        throws PluginResolutionException, PluginContainerException;
 
     /**
      * Looks up the mojo for the specified mojo execution and populates its parameters from the configuration given by

maven-core/src/main/java/org/apache/maven/plugin/PluginContainerException.java

@@ -42,6 +42,13 @@ public class PluginContainerException
 
     private ClassRealm pluginRealm;
 
+    public PluginContainerException( MojoDescriptor mojoDescriptor, ClassRealm pluginRealm, String message, Throwable e )
+    {
+        super( mojoDescriptor, message, e );
+
+        this.pluginRealm = pluginRealm;
+    }
+
     public PluginContainerException( MojoDescriptor mojoDescriptor, ClassRealm pluginRealm, String message, ComponentLookupException e )
     {
         super( mojoDescriptor, message, e );
@@ -49,6 +56,13 @@ public PluginContainerException( MojoDescriptor mojoDescriptor, ClassRealm plugi
         this.pluginRealm = pluginRealm;
     }
 
+    public PluginContainerException( Plugin plugin, ClassRealm pluginRealm, String message, Throwable e )
+    {
+        super( plugin, message, e );
+
+        this.pluginRealm = pluginRealm;
+    }
+
     public PluginContainerException( Plugin plugin, ClassRealm pluginRealm, String message, PlexusConfigurationException e )
     {
         super( plugin, message, e );

maven-core/src/main/java/org/apache/maven/plugin/PluginResolutionException.java

@@ -36,8 +36,9 @@ public class PluginResolutionException
 
     public PluginResolutionException( Plugin plugin, ArtifactResolutionException e )
     {
-        super( "Plugin or one of its dependencies could not be resolved: " + e.getMessage(), e.getGroupId(),
+        super( "Plugin " + plugin.getId() + " or one of its dependencies could not be resolved: " + e.getMessage(),
-               e.getArtifactId(), e.getVersion(), e.getType(), null, e.getRemoteRepositories(), null, e.getCause() );
+               e.getGroupId(), e.getArtifactId(), e.getVersion(), e.getType(), null, e.getRemoteRepositories(), null,
+               e );
         this.plugin = plugin;
     }
 

maven-core/src/main/java/org/apache/maven/plugin/internal/DefaultMavenPluginManager.java

@@ -20,10 +20,12 @@
  */
 
 import java.io.BufferedInputStream;
+import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.PrintStream;
 import java.io.Reader;
 import java.net.MalformedURLException;
 import java.util.ArrayList;
@@ -63,7 +65,6 @@
 import org.apache.maven.plugin.PluginContainerException;
 import org.apache.maven.plugin.PluginDescriptorCache;
 import org.apache.maven.plugin.PluginDescriptorParsingException;
-import org.apache.maven.plugin.PluginManagerException;
 import org.apache.maven.plugin.PluginParameterExpressionEvaluator;
 import org.apache.maven.plugin.PluginRealmCache;
 import org.apache.maven.plugin.PluginResolutionException;
@@ -290,7 +291,7 @@ public MojoDescriptor getMojoDescriptor( Plugin plugin, String goal, RepositoryR
 
     public synchronized void setupPluginRealm( PluginDescriptor pluginDescriptor, MavenSession session,
                                                ClassLoader parent, List<String> imports )
-        throws PluginResolutionException, PluginManagerException
+        throws PluginResolutionException, PluginContainerException
     {
         Plugin plugin = pluginDescriptor.getPlugin();
 
@@ -320,7 +321,7 @@ public synchronized void setupPluginRealm( PluginDescriptor pluginDescriptor, Ma
 
     private void createPluginRealm( PluginDescriptor pluginDescriptor, MavenSession session, ClassLoader parent,
                                     List<String> imports )
-        throws PluginResolutionException, PluginManagerException
+        throws PluginResolutionException, PluginContainerException
     {
         Plugin plugin = pluginDescriptor.getPlugin();
 
@@ -401,13 +402,13 @@ private void createPluginRealm( PluginDescriptor pluginDescriptor, MavenSession
         }
         catch ( PlexusConfigurationException e )
         {
-            throw new PluginManagerException( plugin, "Error in component graph of plugin " + plugin.getId() + ": "
+            throw new PluginContainerException( plugin, pluginRealm, "Error in component graph of plugin "
-                + e.getMessage(), e );
+                + plugin.getId() + ": " + e.getMessage(), e );
         }
         catch ( CycleDetectedInComponentGraphException e )
         {
-            throw new PluginManagerException( plugin, "Error in component graph of plugin " + plugin.getId() + ": "
+            throw new PluginContainerException( plugin, pluginRealm, "Error in component graph of plugin "
-                + e.getMessage(), e );
+                + plugin.getId() + ": " + e.getMessage(), e );
         }
     }
 
@@ -497,13 +498,28 @@ public <T> T getConfiguredMojo( Class<T> mojoInterface, MavenSession session, Mo
 
                 if ( ( cause instanceof NoClassDefFoundError ) || ( cause instanceof ClassNotFoundException ) )
                 {
-                    throw new PluginContainerException( mojoDescriptor, pluginRealm, "Unable to load the mojo '"
+                    ByteArrayOutputStream os = new ByteArrayOutputStream( 1024 );
-                        + mojoDescriptor.getGoal() + "' in the plugin '" + pluginDescriptor.getId()
+                    PrintStream ps = new PrintStream( os );
-                        + "'. A required class is missing: " + cause.getMessage(), e );
+                    ps.println( "Unable to load the mojo '" + mojoDescriptor.getGoal() + "' in the plugin '"
+                        + pluginDescriptor.getId() + "'. A required class is missing: " + cause.getMessage() );
+                    pluginRealm.display( ps );
+
+                    throw new PluginContainerException( mojoDescriptor, pluginRealm, os.toString(), cause );
+                }
+                else if ( cause instanceof LinkageError )
+                {
+                    ByteArrayOutputStream os = new ByteArrayOutputStream( 1024 );
+                    PrintStream ps = new PrintStream( os );
+                    ps.println( "Unable to load the mojo '" + mojoDescriptor.getGoal() + "' in the plugin '"
+                        + pluginDescriptor.getId() + "' due to an API incompatibility: " + e.getClass().getName()
+                        + ": " + cause.getMessage() );
+                    pluginRealm.display( ps );
+
+                    throw new PluginContainerException( mojoDescriptor, pluginRealm, os.toString(), cause );
                 }
 
-                throw new PluginContainerException( mojoDescriptor, pluginRealm, "Unable to find the mojo '"
+                throw new PluginContainerException( mojoDescriptor, pluginRealm, "Unable to load the mojo '"
-                    + mojoDescriptor.getGoal() + "' (or one of its required components) in the plugin '"
+                    + mojoDescriptor.getGoal() + "' (or one of its required components) from the plugin '"
                     + pluginDescriptor.getId() + "'", e );
             }
 
@@ -596,46 +612,23 @@ private void populatePluginFields( Object mojo, MojoDescriptor mojoDescriptor, C
         }
         catch ( NoClassDefFoundError e )
         {
-            throw new PluginConfigurationException( mojoDescriptor.getPluginDescriptor(),
+            ByteArrayOutputStream os = new ByteArrayOutputStream( 1024 );
-                                                    "A required class was missing during configuration of mojo "
+            PrintStream ps = new PrintStream( os );
-                                                        + mojoDescriptor.getId() + ": " + e.getMessage(), e );
+            ps.println( "A required class was missing during configuration of mojo " + mojoDescriptor.getId() + ": "
+                + e.getMessage() );
+            pluginRealm.display( ps );
+
+            throw new PluginConfigurationException( mojoDescriptor.getPluginDescriptor(), os.toString(), e );
         }
         catch ( LinkageError e )
         {
-            if ( logger.isFatalErrorEnabled() )
+            ByteArrayOutputStream os = new ByteArrayOutputStream( 1024 );
-            {
+            PrintStream ps = new PrintStream( os );
-                logger.fatalError( configurator.getClass().getName()
+            ps.println( "An API incompatibility was encountered during configuration of mojo " + mojoDescriptor.getId()
-                    + "#configureComponent(...) caused a linkage error (" + e.getClass().getName()
+                + ": " + e.getClass().getName() + ": " + e.getMessage() );
-                    + ") and may be out-of-date. Check the realms:" );
+            pluginRealm.display( ps );
 
-                StringBuilder sb = new StringBuilder();
+            throw new PluginConfigurationException( mojoDescriptor.getPluginDescriptor(), os.toString(), e );
-                sb.append( "Plugin realm = " + pluginRealm.getId() ).append( '\n' );
-                for ( int i = 0; i < pluginRealm.getURLs().length; i++ )
-                {
-                    sb.append( "urls[" + i + "] = " + pluginRealm.getURLs()[i] );
-                    if ( i != ( pluginRealm.getURLs().length - 1 ) )
-                    {
-                        sb.append( '\n' );
-                    }
-                }
-                logger.fatalError( sb.toString() );
-
-                ClassRealm containerRealm = container.getContainerRealm();
-                sb = new StringBuilder();
-                sb.append( "Container realm = " + containerRealm.getId() ).append( '\n' );
-                for ( int i = 0; i < containerRealm.getURLs().length; i++ )
-                {
-                    sb.append( "urls[" + i + "] = " + containerRealm.getURLs()[i] );
-                    if ( i != ( containerRealm.getURLs().length - 1 ) )
-                    {
-                        sb.append( '\n' );
-                    }
-                }
-                logger.fatalError( sb.toString() );
-            }
-
-            throw new PluginConfigurationException( mojoDescriptor.getPluginDescriptor(), e.getClass().getName() + ": "
-                + e.getMessage(), new ComponentConfigurationException( e ) );
         }
         finally
         {

maven-core/src/main/java/org/apache/maven/project/DefaultModelBuildingListener.java

@@ -118,11 +118,11 @@ public void buildExtensionsAssembled( ModelBuildingEvent event )
             }
             catch ( PluginResolutionException e )
             {
-                event.getProblems().addError( "Unresolveable build extensions: " + e.getMessage(), e );
+                event.getProblems().addError( "Unresolveable build extension: " + e.getMessage(), e );
             }
             catch ( PluginVersionResolutionException e )
             {
-                event.getProblems().addError( "Unresolveable build extensions: " + e.getMessage(), e );
+                event.getProblems().addError( "Unresolveable build extension: " + e.getMessage(), e );
             }
 
             if ( project.getClassRealm() != null )

maven-embedder/src/main/java/org/apache/maven/cli/MavenCli.java

@@ -21,7 +21,9 @@
 import java.io.PrintStream;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.LinkedHashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.Properties;
 import java.util.StringTokenizer;
 import java.util.Map.Entry;
@@ -29,6 +31,8 @@
 import org.apache.commons.cli.CommandLine;
 import org.apache.commons.cli.ParseException;
 import org.apache.maven.Maven;
+import org.apache.maven.exception.DefaultExceptionHandler;
+import org.apache.maven.exception.ExceptionHandler;
 import org.apache.maven.exception.ExceptionSummary;
 import org.apache.maven.execution.DefaultMavenExecutionRequest;
 import org.apache.maven.execution.DefaultMavenExecutionResult;
@@ -37,7 +41,6 @@
 import org.apache.maven.execution.MavenExecutionRequestPopulator;
 import org.apache.maven.execution.MavenExecutionResult;
 import org.apache.maven.model.building.ModelProcessor;
-import org.apache.maven.model.locator.ModelLocator;
 import org.apache.maven.repository.ArtifactTransferListener;
 import org.apache.maven.settings.Settings;
 import org.apache.maven.settings.building.DefaultSettingsBuildingRequest;
@@ -452,35 +455,53 @@ else if ( commandLine.hasOption( CLIManager.ENCRYPT_PASSWORD ) )
         // The exception handling should be handled in Maven itself.
 
         try
+        {
+            return processResult( request, result, showErrors );
+        }
+        finally
+        {
+            if ( fileStream != null )
+            {
+                fileStream.close();
+            }
+        }
+    }
+
+    private int processResult( MavenExecutionRequest request, MavenExecutionResult result, boolean showErrors )
     {
         if ( result.hasExceptions() )
         {
-                ExceptionSummary es = result.getExceptionSummary();
+            ExceptionHandler handler = new DefaultExceptionHandler();
 
-                if ( es == null )
+            Map<String, String> references = new LinkedHashMap<String, String>();
+
+            for ( Throwable exception : result.getExceptions() )
             {
-                    logger.error( "", result.getExceptions().get( 0 ) );
+                ExceptionSummary summary = handler.handleException( exception );
-                }
+
-                else
+                logSummary( summary, references, "", showErrors );
-                {
-                    if ( showErrors )
-                    {
-                        logger.error( es.getMessage(), es.getException() );
-                    }
-                    else
-                    {
-                        logger.error( es.getMessage() );
-                        logger.error( "To see the full stack trace of the error, re-run Maven with the -e switch." );
             }
 
+            logger.error( "" );
+
+            if ( !showErrors )
+            {
+                logger.error( "To see the full stack trace of the errors, re-run Maven with the -e switch." );
+            }
+            if ( !logger.isDebugEnabled() )
+            {
                 logger.error( "Re-run Maven using the -X switch to enable full debug logging." );
+            }
 
-                    if ( StringUtils.isNotEmpty( es.getReference() ) )
+            if ( !references.isEmpty() )
             {
                 logger.error( "" );
-                        logger.error( "For more information about the error and possible solutions"
+                logger.error( "For more information about the errors and possible solutions"
-                            + ", please try the following article:" );
+                    + ", please read the following articles:" );
-                        logger.error( "  " + es.getReference() );
+
+                for ( Map.Entry<String, String> entry : references.entrySet() )
+                {
+                    logger.error( entry.getValue() + " " + entry.getKey() );
                 }
             }
 
@@ -500,13 +521,36 @@ else if ( commandLine.hasOption( CLIManager.ENCRYPT_PASSWORD ) )
             return 0;
         }
     }
-        finally
+
+    private void logSummary( ExceptionSummary summary, Map<String, String> references, String indent, boolean showErrors )
     {
-            if ( fileStream != null )
+        String referenceKey = "";
+
+        if ( StringUtils.isNotEmpty( summary.getReference() ) )
         {
-                fileStream.close();
+            referenceKey = references.get( summary.getReference() );
+            if ( referenceKey == null )
+            {
+                referenceKey = "[" + references.size() + "]";
+                references.put( summary.getReference(), referenceKey );
             }
         }
+
+        if ( showErrors )
+        {
+            logger.error( indent + referenceKey, summary.getException() );
+        }
+        else
+        {
+            logger.error( indent + summary.getMessage() + " " + referenceKey );
+        }
+
+        indent += "  ";
+
+        for ( ExceptionSummary child : summary.getChildren() )
+        {
+            logSummary( child, references, indent, showErrors );
+        }
     }
 
     protected ModelProcessor createModelProcessor( PlexusContainer container )