pomConfiguration = pluginExecution.getDelegate().getConfiguration();
            } else if (allowPluginLevelConfig) {
                pomConfiguration = plugin.getDelegate().getConfiguration();
            }

            XmlNode mojoConfiguration = mojoExecution.getConfiguration() != null
                    ? mojoExecution.getConfiguration().getDom()
                    : null;

    } // -- void addExecution( Execution )

    /**
     * Get configuration to pass to all goals run in this phase.
     *
     * @return Object
     */
    public Object getConfiguration() {
        return this.configuration;
    } // -- Object getConfiguration()

    /**
     * Method getExecutions.
     *
     * @return List
     */
    public java.util.List<Execution> getExecutions() {

        Xpp3Dom src = (Xpp3Dom) source.getConfiguration();
        if (src != null) {
            Xpp3Dom tgt = (Xpp3Dom) target.getConfiguration();
            if (tgt == null) {
                tgt = Xpp3Dom.mergeXpp3Dom(new Xpp3Dom(src), tgt);
            } else {
                tgt = Xpp3Dom.mergeXpp3Dom(tgt, src);
            }
            target.setConfiguration(tgt);
        }
    }

     */
    Object getConfiguration();

    /**
     * Sets the configuration to unmarshal into the bean. The configuration should be taken from
     * {@link org.apache.maven.model.ConfigurationContainer#getConfiguration()} or a similar source.
     * Fully equivalent to {@code setConfiguration(configuration, null)}.
     *

        MojoDescriptor mojoDescriptor = mojoExecution.getMojoDescriptor();

        XmlNode executionConfiguration = mojoExecution.getConfiguration() != null
                ? mojoExecution.getConfiguration().getDom()
                : null;
        if (executionConfiguration == null) {
            executionConfiguration = XmlNode.newInstance("configuration");
        }

        for (Plugin plugin : plugins) {
            Xpp3Dom pluginConfiguration = (Xpp3Dom) plugin.getConfiguration();

            if (pluginConfiguration != null) {
                for (PluginExecution execution : plugin.getExecutions()) {
                    Xpp3Dom executionConfiguration = (Xpp3Dom) execution.getConfiguration();

                    executionConfiguration =

            Xpp3Dom config0 = (Xpp3Dom) jdks.getToolchains().get(0).getConfiguration();
            assertEquals("lib/tools.jar", config0.getChild("toolsJar").getValue());
            assertEquals(2, config0.getChildCount());
            Xpp3Dom config1 = (Xpp3Dom) jdks.getToolchains().get(1).getConfiguration();
            assertEquals(2, config1.getChildCount());

  run a reactorized project...the successive calls may leave behind configuration
  artifacts from invocation to invocation.

Maven Modifications

* DefaultPluginManager

  s/getMojoConfiguration()/getConfiguration()/g

  That should re-enable usage of mojo configuration. Ideally, we won't need any
  of the code that references this method, since the container should provide

                                .configuration(phase.getConfiguration())
                                .executions(phase.getExecutions().stream()
                                        .map(exec -> org.apache.maven.api.model.PluginExecution.newBuilder()
                                                .goals(exec.getGoals())
                                                .configuration(exec.getConfiguration())

                    if (pluginExecutionId.equals(execution.getId())) {
                        setConfiguration(execution.getConfiguration());
                        break;
                    }
                }
            } else {
                setConfiguration(plugin.getConfiguration());
            }
        }
        return this;
    }