[MNG-6326] Make the build fail if core extensions can not be loaded (#648)

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

@@ -743,6 +743,7 @@ public class MavenCli
 
     private List<CoreExtensionEntry> loadCoreExtensions( CliRequest cliRequest, ClassRealm containerRealm,
                                                          Set<String> providedArtifacts )
+            throws Exception
     {
         if ( cliRequest.multiModuleProjectDirectory == null )
         {
@@ -755,8 +756,6 @@ public class MavenCli
             return Collections.emptyList();
         }
 
-        try
-        {
         List<CoreExtension> extensions = readCoreExtensionsDescriptor( extensionsFile );
         if ( extensions.isEmpty() )
         {
@@ -814,17 +813,6 @@ public class MavenCli
             container.dispose();
         }
     }
-        catch ( RuntimeException e )
-        {
-            // runtime exceptions are most likely bugs in maven, let them bubble up to the user
-            throw e;
-        }
-        catch ( Exception e )
-        {
-            slf4jLogger.warn( "Failed to read extensions descriptor from '{}'", extensionsFile, e );
-        }
-        return Collections.emptyList();
-    }
 
     private List<CoreExtension> readCoreExtensionsDescriptor( File extensionsFile )
         throws IOException, XmlPullParserException

maven-embedder/src/main/java/org/apache/maven/cli/internal/BootstrapCoreExtensionManager.java

@@ -128,18 +128,29 @@ public class BootstrapCoreExtensionManager
 
     private List<Artifact> resolveExtension( CoreExtension extension, RepositorySystemSession repoSession,
                                              List<RemoteRepository> repositories, DependencyFilter dependencyFilter )
-        throws PluginResolutionException
+        throws ExtensionResolutionException
     {
+        try
+        {
+            // TODO: enhance the PluginDependenciesResolver to provide a
+            // TODO:    resolveCoreExtension method which uses a CoreExtension
+            // TODO:    object instead of a Plugin as this makes no sense
             Plugin plugin = new Plugin();
             plugin.setGroupId( extension.getGroupId() );
             plugin.setArtifactId( extension.getArtifactId() );
             plugin.setVersion( extension.getVersion() );
 
-        DependencyNode root =
+            DependencyNode root = pluginDependenciesResolver
-            pluginDependenciesResolver.resolveCoreExtension( plugin, dependencyFilter, repositories, repoSession );
+                    .resolveCoreExtension( plugin, dependencyFilter, repositories, repoSession );
             PreorderNodeListGenerator nlg = new PreorderNodeListGenerator();
             root.accept( nlg );
 
             return nlg.getArtifacts( false );
         }
+        catch ( PluginResolutionException e )
+        {
+            throw new ExtensionResolutionException( extension, e.getCause() );
+        }
+    }
+
 }

maven-embedder/src/main/java/org/apache/maven/cli/internal/ExtensionResolutionException.java

@@ -0,0 +1,47 @@
+package org.apache.maven.cli.internal;
+
+/*
+ * 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 org.apache.maven.cli.internal.extension.model.CoreExtension;
+
+/**
+ * Exception occurring trying to resolve a plugin.
+ *
+ * @author <a href="mailto:brett@apache.org">Brett Porter</a>
+ */
+public class ExtensionResolutionException
+    extends Exception
+{
+
+    private final CoreExtension extension;
+
+    public ExtensionResolutionException( CoreExtension extension, Throwable cause )
+    {
+        super( "Extension " + extension.getId() + " or one of its dependencies could not be resolved: "
+                        + cause.getMessage(), cause );
+        this.extension = extension;
+    }
+
+    public CoreExtension getExtension()
+    {
+        return extension;
+    }
+
+}

maven-embedder/src/main/mdo/core-extensions.mdo

@@ -83,6 +83,32 @@
           <type>String</type>
         </field>
       </fields>
+      <codeSegments>
+        <codeSegment>
+          <version>1.0.0+</version>
+          <code>
+            <![CDATA[
+    /**
+     * Gets the identifier of the extension.
+     *
+     * @return The extension id in the form {@code <groupId>:<artifactId>:<version>}, never {@code null}.
+     */
+    public String getId()
+    {
+        StringBuilder id = new StringBuilder( 128 );
+
+        id.append( ( getGroupId() == null ) ? "[unknown-group-id]" : getGroupId() );
+        id.append( ":" );
+        id.append( ( getArtifactId() == null ) ? "[unknown-artifact-id]" : getArtifactId() );
+        id.append( ":" );
+        id.append( ( getVersion() == null ) ? "[unknown-version]" : getVersion() );
+
+        return id.toString();
+    }
+            ]]>
+          </code>
+        </codeSegment>
+      </codeSegments>
     </class>
   </classes>
 </model>