/*
    * 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.maven.plugins.invoker;
  
  import java.io.BufferedWriter;
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.FileOutputStream;
  import java.io.FileWriter;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStreamWriter;
  import java.io.Reader;
  import java.io.Writer;
  import java.nio.charset.Charset;
  import java.nio.file.Files;
  import java.nio.file.Path;
  import java.nio.file.Paths;
  import java.nio.file.StandardCopyOption;
  import java.text.MessageFormat;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.LinkedHashMap;
  import java.util.LinkedHashSet;
  import java.util.List;
  import java.util.Locale;
  import java.util.Map;
  import java.util.Objects;
  import java.util.Optional;
  import java.util.Properties;
  import java.util.Set;
  import java.util.TreeSet;
  import java.util.stream.Collectors;
  
  import org.apache.maven.artifact.Artifact;
  import org.apache.maven.execution.MavenSession;
  import org.apache.maven.model.Model;
  import org.apache.maven.plugin.AbstractMojo;
  import org.apache.maven.plugin.MojoExecution;
  import org.apache.maven.plugin.MojoExecutionException;
  import org.apache.maven.plugin.MojoFailureException;
  import org.apache.maven.plugin.logging.Log;
  import org.apache.maven.plugins.annotations.Parameter;
  import org.apache.maven.plugins.invoker.model.BuildJob;
  import org.apache.maven.plugins.invoker.model.io.xpp3.BuildJobXpp3Writer;
  import org.apache.maven.project.MavenProject;
  import org.apache.maven.settings.Settings;
  import org.apache.maven.settings.SettingsUtils;
  import org.apache.maven.settings.TrackableBase;
  import org.apache.maven.settings.building.DefaultSettingsBuildingRequest;
  import org.apache.maven.settings.building.SettingsBuilder;
  import org.apache.maven.settings.building.SettingsBuildingException;
  import org.apache.maven.settings.building.SettingsBuildingRequest;
  import org.apache.maven.settings.io.xpp3.SettingsXpp3Writer;
  import org.apache.maven.shared.invoker.CommandLineConfigurationException;
  import org.apache.maven.shared.invoker.DefaultInvocationRequest;
  import org.apache.maven.shared.invoker.InvocationRequest;
  import org.apache.maven.shared.invoker.InvocationResult;
  import org.apache.maven.shared.invoker.Invoker;
  import org.apache.maven.shared.invoker.MavenCommandLineBuilder;
  import org.apache.maven.shared.invoker.MavenInvocationException;
  import org.apache.maven.shared.scriptinterpreter.ScriptException;
  import org.apache.maven.shared.scriptinterpreter.ScriptReturnException;
  import org.apache.maven.shared.scriptinterpreter.ScriptRunner;
  import org.apache.maven.shared.utils.logging.MessageBuilder;
  import org.apache.maven.toolchain.ToolchainManager;
  import org.codehaus.plexus.interpolation.InterpolationException;
  import org.codehaus.plexus.interpolation.Interpolator;
  import org.codehaus.plexus.interpolation.MapBasedValueSource;
  import org.codehaus.plexus.interpolation.RegexBasedInterpolator;
  import org.codehaus.plexus.util.DirectoryScanner;
  import org.codehaus.plexus.util.FileUtils;
  import org.codehaus.plexus.util.IOUtil;
  import org.codehaus.plexus.util.InterpolationFilterReader;
  import org.codehaus.plexus.util.NioFiles;
  import org.codehaus.plexus.util.ReflectionUtils;
  import org.codehaus.plexus.util.cli.CommandLineException;
  import org.codehaus.plexus.util.cli.CommandLineUtils;
  import org.codehaus.plexus.util.cli.Commandline;
 import org.codehaus.plexus.util.cli.StreamConsumer;
 import org.codehaus.plexus.util.xml.XmlStreamReader;
 import org.codehaus.plexus.util.xml.XmlStreamWriter;
 import org.codehaus.plexus.util.xml.Xpp3Dom;
 import org.codehaus.plexus.util.xml.Xpp3DomWriter;
 
 import static org.apache.maven.shared.utils.logging.MessageUtils.buffer;
 
 /**
  * Provides common code for mojos invoking sub builds.
  *
  * @author Stephen Connolly
  * @since 15-Aug-2009 09:09:29
  */
 public abstract class AbstractInvokerMojo extends AbstractMojo {
     private static final float ONE_SECOND = 1000.0f;
 
     /**
      * The zero-based column index where to print the invoker result.
      */
     private static final int RESULT_COLUMN = 60;
 
     /**
      * Flag used to suppress certain invocations. This is useful in tailoring the build using profiles.
      *
      * @since 1.1
      */
     @Parameter(property = "invoker.skip", defaultValue = "false")
     private boolean skipInvocation;
 
     /**
      * Flag used to suppress the summary output notifying of successes and failures. If set to <code>true</code>, the
      * only indication of the build's success or failure will be the effect it has on the main build (if it fails, the
      * main build should fail as well). If {@link #streamLogs} is enabled, the sub-build summary will also provide an
      * indication.
      *
      * @since 1.0
      */
     @Parameter(defaultValue = "false")
     protected boolean suppressSummaries;
 
     /**
      * Flag used to determine whether the build logs should be output to the normal mojo log.
      *
      * @since 1.0
      */
     @Parameter(property = "invoker.streamLogs", defaultValue = "false")
     private boolean streamLogs;
 
     /**
      * The local repository for caching artifacts. It is strongly recommended to specify a path to an isolated
      * repository like <code>${project.build.directory}/it-repo</code>. Otherwise, your ordinary local repository will
      * be used, potentially soiling it with broken artifacts.
      *
      * @since 1.0
      */
     @Parameter(property = "invoker.localRepositoryPath", defaultValue = "${settings.localRepository}")
     private File localRepositoryPath;
 
     /**
      * Directory to search for integration tests.
      *
      * @since 1.0
      */
     @Parameter(property = "invoker.projectsDirectory", defaultValue = "${basedir}/src/it/")
     private File projectsDirectory;
 
     /**
      * Base directory where all build reports are written to. Every execution of an integration test will produce an XML
      * file which contains the information about success or failure of that particular build job. The format of the
      * resulting XML file is documented in the given <a href="./build-job.html">build-job</a> reference.
      *
      * @since 1.4
      */
     @Parameter(property = "invoker.reportsDirectory", defaultValue = "${project.build.directory}/invoker-reports")
     private File reportsDirectory;
 
     /**
      * A flag to disable the generation of build reports.
      *
      * @since 1.4
      */
     @Parameter(property = "invoker.disableReports", defaultValue = "false")
     private boolean disableReports;
 
     /**
      * <p>Directory to which projects should be cloned prior to execution. If not set or set to special value {@code none},
      * each integration test will be run in the directory in which the corresponding IT POM was found. In this case, you most likely want to
      * configure your SCM to ignore <code>target</code> and <code>build.log</code> in the test's base directory.
      *
      * <p><b>Exception</b>: when a project using invoker plugin is of <i>maven-plugin</i> packaging:
      * In such a case IT projects will be cloned to and executed in <code>target/its</code> by default.
      *
      * <p><b>Note</b>: cloning needs to be enabled for properties filtering to work.
      *
      * @since 1.1
      */
     @Parameter(property = "invoker.cloneProjectsTo")
     private File cloneProjectsTo;
 
     // CHECKSTYLE_OFF: LineLength
     /**
      * Some files are normally excluded when copying the IT projects from the directory specified by the parameter
      * projectsDirectory to the directory given by cloneProjectsTo (e.g. <code>.svn</code>, <code>CVS</code>,
      * <code>*~</code>, etc: see <a href=
      * "https://codehaus-plexus.github.io/plexus-utils/apidocs/org/codehaus/plexus/util/AbstractScanner.html#DEFAULTEXCLUDES">
      * reference</a> for full list). Setting this parameter to <code>true</code> will cause all files to be copied to
      * the <code>cloneProjectsTo</code> directory.
      *
      * @since 1.2
      */
     @Parameter(defaultValue = "false")
     private boolean cloneAllFiles;
     // CHECKSTYLE_ON: LineLength
 
     /**
      * Ensure the {@link #cloneProjectsTo} directory is not polluted with files from earlier invoker runs.
      *
      * @since 1.6
      */
     @Parameter(defaultValue = "true")
     private boolean cloneClean;
 
     /**
      * A single POM to build, skipping any scanning parameters and behavior.
      *
      * @since 1.0
      */
     @Parameter(property = "invoker.pom")
     private File pom;
 
     /**
      * Include patterns for searching the integration test directory for projects. This parameter is meant to be set
      * from the POM. If this parameter is not set, the plugin will search for all <code>pom.xml</code> files one
      * directory below {@link #projectsDirectory} (i.e. <code>*&#47;pom.xml</code>).<br>
      * <br>
      * Starting with version 1.3, mere directories can also be matched by these patterns. For example, the include
      * pattern <code>*</code> will run Maven builds on all immediate sub directories of {@link #projectsDirectory},
      * regardless if they contain a <code>pom.xml</code>. This allows to perform builds that need/should not depend on
      * the existence of a POM.
      *
      * @since 1.0
      */
     @Parameter
     private List<String> pomIncludes = Collections.singletonList("*/pom.xml");
 
     /**
      * Exclude patterns for searching the integration test directory. This parameter is meant to be set from the POM. By
      * default, no POM files are excluded. For the convenience of using an include pattern like <code>*</code>, the
      * custom settings file specified by the parameter {@link #settingsFile} will always be excluded automatically.
      *
      * @since 1.0
      */
     @Parameter
     private List<String> pomExcludes = Collections.emptyList();
 
     /**
      * Include patterns for searching the projects directory for projects that need to be run before the other projects.
      * This parameter allows to declare projects that perform setup tasks like installing utility artifacts into the
      * local repository. Projects matched by these patterns are implicitly excluded from the scan for ordinary projects.
      * Also, the exclusions defined by the parameter {@link #pomExcludes} apply to the setup projects, too. Default
      * value is: <code>setup*&#47;pom.xml</code>.
      *
      * @since 1.3
      */
     @Parameter
     private List<String> setupIncludes = Collections.singletonList("setup*/pom.xml");
 
     /**
      * The list of goals to execute on each project. Default value is: <code>package</code>.
      *
      * @since 1.0
      */
     @Parameter
     private List<String> goals = Collections.singletonList("package");
 
     /**
      * Relative path of a selector script to run prior in order to decide if the build should be executed. This script
      * may be written with either BeanShell or Groovy. If the file extension is omitted (e.g. <code>selector</code>),
      * the plugin searches for the file by trying out the well-known extensions <code>.bsh</code> and
      * <code>.groovy</code>. If this script exists for a particular project but returns any non-null value different
      * from <code>true</code>, the corresponding build is flagged as skipped. In this case, none of the pre-build hook
      * script, Maven nor the post-build hook script will be invoked. If this script throws an exception, the
      * corresponding build is flagged as in error, and none of the pre-build hook script, Maven not the post-build hook
      * script will be invoked.
      *
      * @since 1.5
      */
     @Parameter(property = "invoker.selectorScript", defaultValue = "selector")
     private String selectorScript;
 
     /**
      * Relative path of a pre-build hook script to run prior to executing the build. This script may be written with
      * either BeanShell or Groovy (since 1.3). If the file extension is omitted (e.g. <code>prebuild</code>), the plugin
      * searches for the file by trying out the well-known extensions <code>.bsh</code> and <code>.groovy</code>. If this
      * script exists for a particular project but returns any non-null value different from <code>true</code> or throws
      * an exception, the corresponding build is flagged as a failure. In this case, neither Maven nor the post-build
      * hook script will be invoked.
      *
      * @since 1.0
      */
     @Parameter(property = "invoker.preBuildHookScript", defaultValue = "prebuild")
     private String preBuildHookScript;
 
     /**
      * Relative path of a cleanup/verification hook script to run after executing the build. This script may be written
      * with either BeanShell or Groovy (since 1.3). If the file extension is omitted (e.g. <code>verify</code>), the
      * plugin searches for the file by trying out the well-known extensions <code>.bsh</code> and <code>.groovy</code>.
      * If this script exists for a particular project but returns any non-null value different from <code>true</code> or
      * throws an exception, the corresponding build is flagged as a failure.
      *
      * @since 1.0
      */
     @Parameter(property = "invoker.postBuildHookScript", defaultValue = "postbuild")
     private String postBuildHookScript;
 
     /**
      * Location of a properties file that defines CLI properties for the test.
      *
      * @since 1.0
      */
     @Parameter(property = "invoker.testPropertiesFile", defaultValue = "test.properties")
     private String testPropertiesFile;
 
     /**
      * Common set of properties to pass in on each project's command line, via -D parameters.
      *
      * @since 1.1
      */
     @Parameter
     private Map<String, String> properties;
 
     /**
      * Whether to show errors in the build output.
      *
      * @since 1.0
      */
     @Parameter(property = "invoker.showErrors", defaultValue = "false")
     private boolean showErrors;
 
     /**
      * Whether to show debug statements in the build output.
      *
      * @since 1.0
      */
     @Parameter(property = "invoker.debug", defaultValue = "false")
     private boolean debug;
 
     /**
      * Whether to execute Maven in quiet mode.
      *
      * @since 3.3.0
      */
     @Parameter(property = "invoker.quiet", defaultValue = "false")
     private boolean quiet;
 
     /**
      * Suppress logging to the <code>build.log</code> file.
      *
      * @since 1.0
      */
     @Parameter(property = "invoker.noLog", defaultValue = "false")
     private boolean noLog;
 
     /**
      * By default a {@code build.log} is created in the root of the project. By setting this folder
      * files are written to a different folder, respecting the structure of the projectsDirectory.
      *
      * @since 3.2.0
      */
     @Parameter
     private File logDirectory;
 
     /**
      * List of profile identifiers to explicitly trigger in the build.
      *
      * @since 1.1
      */
     @Parameter
     private List<String> profiles;
 
     /**
      * A list of additional properties which will be used to filter tokens in POMs and goal files.
      *
      * @since 1.3
      */
     @Parameter
     private Map<String, String> filterProperties;
 
     /**
      * A comma separated list of projectname patterns to run. Specify this parameter to run individual tests by file
      * name, overriding the {@link #setupIncludes}, {@link #pomIncludes} and {@link #pomExcludes} parameters. Each
      * pattern you specify here will be used to create an include/exclude pattern formatted like
      * <code>${projectsDirectory}/<i>pattern</i></code>. To exclude a test, prefix the pattern with a '<code>!</code>'.
      * So you can just type <nobr><code>-Dinvoker.test=SimpleTest,Comp*Test,!Compare*</code></nobr> to run builds in
      * <code>${projectsDirectory}/SimpleTest</code> and <code>${projectsDirectory}/ComplexTest</code>, but not
      * <code>${projectsDirectory}/CompareTest</code>
      *
      * @since 1.1 (exclusion since 1.8)
      */
     @Parameter(property = "invoker.test")
     private String invokerTest;
 
     /**
      * Path to an alternate <code>settings.xml</code> to use for Maven invocation with all ITs. Note that the
      * <code>&lt;localRepository&gt;</code> element of this settings file is always ignored, i.e. the path given by the
      * parameter {@link #localRepositoryPath} is dominant.
      *
      * @since 1.2
      */
     @Parameter(property = "invoker.settingsFile")
     private File settingsFile;
 
     /**
      * The <code>MAVEN_OPTS</code> environment variable to use when invoking Maven. This value can be overridden for
      * individual integration tests by using {@link #invokerPropertiesFile}.
      * <br>
      * Since the version <b>3.7.0</b> using an alternate syntax for mavenOpts, <code>@{...}</code>
      * allows late replacement of properties when the plugin is executed,
      * so properties that have been modified by other plugins will be picked up correctly.
      *
      * @since 1.2
      */
     @Parameter(property = "invoker.mavenOpts")
     private String mavenOpts;
 
     /**
      * The home directory of the Maven installation to use for the forked builds. Defaults to the current Maven
      * installation.
      *
      * @since 1.3
      */
     @Parameter(property = "invoker.mavenHome")
     private File mavenHome;
 
     /**
      * The path to the Maven executable to use. This can either be a file relative to
      * <code>${maven.home}/bin/</code>, a file relative to the test project workspace, or an
      * absolute file path.
      *
      * @since 1.8
      */
     @Parameter(property = "invoker.mavenExecutable")
     private String mavenExecutable;
 
     /**
      * The <code>JAVA_HOME</code> environment variable to use for forked Maven invocations. Defaults to the current Java
      * home directory.
      *
      * @since 1.3
      */
     @Parameter(property = "invoker.javaHome")
     private File javaHome;
 
     /**
      * The file encoding for the pre-/post-build scripts and the list files for goals and profiles.
      *
      * @since 1.2
      */
     @Parameter(property = "encoding", defaultValue = "${project.build.sourceEncoding}")
     private String encoding;
 
     /**
      * A flag to configure whether the test class path of the project under test should be included
      * in the class path of the pre/post-build scripts. If set to <code>false</code>, the class
      * path of script interpreter consists only of the <a href="dependencies.html">runtime
      * dependencies</a> of the Maven Invoker Plugin. If set the <code>true</code>, the project's
      * test class path will be prepended to the interpreter class path. Among others, this feature
      * allows the scripts to access utility classes from the test sources of your project.
      *
      * @since 1.2
      */
     @Parameter(property = "invoker.addTestClassPath", defaultValue = "false")
     private boolean addTestClassPath;
 
     /**
      * The name of an optional project-specific file that contains properties used to specify settings for an individual
      * Maven invocation. Any property present in the file will override the corresponding setting from the plugin
      * configuration. The values of the properties are filtered and may use expressions like
      * <code>${project.version}</code> to reference project properties or values from the parameter
      * {@link #filterProperties}.<p/>
      *
      * <p>
      * As of 3.2.0 it is possible to put this folder in any of the ancestor folders, where properties will be inherited.
      * This way you can provide a single properties file for a group of projects
      * </p>
      *
      * The snippet below describes the supported properties:
      * <pre>
      * # A comma or space separated list of goals/phases to execute, may
      * # specify an empty list to execute the default goal of the IT project.
      * # Environment variables used by maven plugins can be added here
      * invoker.goals = clean install -Dplugin.variable=value
      *
      * # Or you can give things like this if you need.
      * invoker.goals = -T2 clean verify
      *
      * # Optionally, a list of goals to run during further invocations of Maven
      * invoker.goals.2 = ${project.groupId}:${project.artifactId}:${project.version}:run
      *
      * # A comma or space separated list of profiles to activate
      * # can be indexed
      * invoker.profiles = its,jdk15
      *
      * # The path to an alternative POM or base directory to invoke Maven on, defaults to the
      * # project that was originally specified in the plugin configuration
      * # Since plugin version 1.4
      * # can be indexed
      * invoker.project = sub-module
      *
      * # The maven executable can either be a file relative to <code>${maven.home}/bin/</code>, test project workspace
      * # or an absolute file.
      * # Since plugin version 3.3.0
      * # can be indexed
      * invoker.mavenExecutable = mvnw
      *
      * # The value for the environment variable MAVEN_OPTS
      * # can be indexed
      * invoker.mavenOpts = -Dfile.encoding=UTF-16 -Xms32m -Xmx256m
      *
      * # Possible values are &quot;fail-fast&quot; (default), &quot;fail-at-end&quot; and &quot;fail-never&quot;
      * # can be indexed
      * invoker.failureBehavior = fail-never
      *
      * # The expected result of the build, possible values are &quot;success&quot; (default) and &quot;failure&quot;
      * # can be indexed
      * invoker.buildResult = failure
      *
      * # A boolean value controlling the aggregator mode of Maven, defaults to &quot;false&quot;
      *
      * # can be indexed
      * invoker.nonRecursive = true
      *
      * # A boolean value controlling the network behavior of Maven, defaults to &quot;false&quot;
      * # Since plugin version 1.4
      * # can be indexed
      * invoker.offline = true
      *
      * # The path to the properties file from which to load user properties, defaults to the
      * # filename given by the plugin parameter testPropertiesFile
      * # Since plugin version 1.4
      * # can be indexed
      * invoker.userPropertiesFile = test.properties
      *
      * # An optional human friendly name and description for this build job.
      * # Both name and description have to be set to be included in the build reports.
      * # Since plugin version 1.4
      * invoker.name = Test Build 01
      * invoker.description = Checks the support for build reports.
      *
      * # A comma separated list of JRE versions on which this build job should be run.
      * # Since plugin version 1.4
      * invoker.java.version = 1.4+, !1.4.1, 1.7-
      *
      * # A comma separated list of OS families on which this build job should be run.
      * # Since plugin version 1.4
      * invoker.os.family = !windows, unix, mac
      *
      * # A comma separated list of Maven versions on which this build should be run.
      * # Since plugin version 1.5
      * invoker.maven.version = 2.0.10+, !2.1.0, !2.2.0
      *
      * # A mapping for toolchain to ensure it exists
      * # Since plugin version 3.2.0
      * invoker.toolchain.&lt;type&gt;.&lt;provides&gt; = value
      * # Exact match
      * invoker.toolchain.jdk.version = 11
      * # Range match
      * invoker.toolchain.jdk.version = [11,12)
      *
      * # For java.version, maven.version, os.family and toolchain it is possible to define multiple selectors.
      * # If one of the indexed selectors matches, the test is executed.
      * # With the invoker.x.y equivalents you can specify global matchers.
      * selector.1.java.version = 1.8+
      * selector.1.maven.version = 3.2.5+
      * selector.1.os.family = !windows
      * selector.2.maven.version = 3.0+
      * selector.3.java.version = 9+
      *
      * # A boolean value controlling the debug logging level of Maven, , defaults to &quot;false&quot;
      * # Since plugin version 1.8
      * # can be indexed
      * invoker.debug = true
      *
      * # Whether to execute Maven in quiet mode
      * # Since plugin version 3.3.0
      * # can be indexed
      * invoker.quiet = true
      *
      * The execution timeout in seconds.
      * # Since plugin version 3.0.2
      * # can be indexed
      * invoker.timeoutInSeconds = 5
      *
      * # Path to an alternate settings.xml to use for Maven invocation with this IT.
      * # Since plugin version 3.0.1
      * # can be indexed
      * invoker.settingsFile = ../
      *
      * # An integer value to control run order of projects. sorted in the descending order of the ordinal.
      * # In other words, the BuildJobs with the highest numbers will be executed first
      * # Default value is 0 (zero)
      * # Since plugin version 3.2.1
      * invoker.ordinal = 3
      *
      * # The additional value for the environment variable.
      * # Since plugin version 3.2.2
      * invoker.environmentVariables.&lt;variableName&gt; = variableValue
      * invoker.environmentVariables.MY_ENV_NAME = myEnvValue
      *
      * # A boolean value indicating a check for missing releases and updated snapshots on remote repositories to be done
      * # Passed to the invoker. Same as passing -U, --update-snapshots flag on the command line
      * # Since plugin version 3.4.0
      * invoker.updateSnapshots = true
      *
      * </pre>
      *
      * @since 1.2
      */
     @Parameter(property = "invoker.invokerPropertiesFile", defaultValue = "invoker.properties")
     private String invokerPropertiesFile;
 
     /**
      * A flag to instruct Maven to print the current version details prior to running integration
      * tests.
      *
      * @since 1.4
      */
     @Parameter(property = "invoker.showVersion", defaultValue = "false")
     private boolean showVersion;
 
     /**
      * Number of threads for running tests in parallel. This will be the number of maven forked process in parallel.
      * When terminated with "C", the number part is multiplied by the number of processors (cores) available
      * to the Java virtual machine. Floating point value are only accepted together with "C".</p>
      *
      * <p>Example values: "1.5C", "4"</p>
      *
      * @since 1.6
      */
     @Parameter(property = "invoker.parallelThreads", defaultValue = "1")
     private String parallelThreads;
 
     /**
      * If enablef and if you have a settings file configured for the execution, it will be merged
      * with your user settings.
      *
      * @since 1.6
      */
     @Parameter(property = "invoker.mergeUserSettings", defaultValue = "false")
     private boolean mergeUserSettings;
 
     /**
      * Additional environment variables to set on the command line.
      *
      * @since 1.8
      */
     @Parameter
     private Map<String, String> environmentVariables;
 
     /**
      * Additional variables for use in the hook scripts.
      *
      * @since 1.9
      */
     @Parameter
     private Map<String, String> scriptVariables;
 
     /**
      * The timeout to apply to tests. Any tests taking longer than this time will be aborted and
      * the test will be flagged as having failed.
      *
      * <p>If set to <code>0</code>, then no timeout is applied.
      *
      * @since 3.0.2
      */
     @Parameter(defaultValue = "0", property = "invoker.timeoutInSeconds")
     private int timeoutInSeconds;
 
     /**
      * Produce a test report in the JUnit XML format.
      *
      * @since 3.1.2
      */
     @Parameter(defaultValue = "false", property = "invoker.writeJunitReport")
     private boolean writeJunitReport;
 
     /**
      * The package name to use within any JUnit XML reports produced by this plugin.
      *
      * @since 3.1.2
      */
     @Parameter(defaultValue = "maven.invoker.it", property = "invoker.junitPackageName")
     private String junitPackageName = "maven.invoker.it";
 
     /**
      * A flag congiguring whether to invoke Maven projects if their sources have been modified
      * since they were last built. Only works in conjunction with <code>cloneProjectsTo</code>.
      *
      * @since 3.2.2
      */
     @Parameter(defaultValue = "false", property = "invoker.updateOnly")
     private boolean updateOnly = false;
 
     /**
      * Force a check for missing releases and updated snapshots on remote repositories. This is passed to the invoked
      * maven projects (it is the same as if you were to use the -U, --update-snapshots flag on the command line).
      *
      * @since 3.4.0
      */
     @Parameter(defaultValue = "false", property = "invoker.updateSnapshots")
     private boolean updateSnapshots;
 
     /**
      * Projects that are cloned undergo some filtering. In order to grab all projects and make sure
      * they are all filtered, projects are read and parsed. In some cases, this may not be a desired
      * behavior (especially when some pom.xml cannot be parsed by Maven directly).  In such cases,
      * the exact list of projects can be set using this field, avoiding the parsing of all pom.xml
      * files found.
      *
      * @since 3.9.0
      */
     @Parameter
     private List<String> collectedProjects;
 
     /**
      * Specifies the number of times a failed execution should be retried.
      *
      * @since 3.10.0
      */
     @Parameter(defaultValue = "0", property = "invoker.rerunFailingTestsCount")
     private int rerunFailingTestsCount;
 
     // internal state variables
 
     /**
      * The scripter runner that is responsible to execute hook scripts.
      */
     private ScriptRunner scriptRunner;
 
     /**
      * A string used to prefix the file name of the filtered POMs in case the POMs couldn't be filtered in-place (i.e.
      * the projects were not cloned to a temporary directory), can be <code>null</code>. This will be set to
      * <code>null</code> if the POMs have already been filtered during cloning.
      */
     private String filteredPomPrefix = "interpolated-";
 
     /**
      * The version of Maven which is used to run the builds
      */
     private String actualMavenVersion;
 
     // used components - readonly parameters
 
     @Parameter(property = "plugin.artifacts", required = true, readonly = true)
     private List<Artifact> pluginArtifacts;
 
     @Parameter(defaultValue = "${project.testClasspathElements}", readonly = true)
     private List<String> testClassPath;
 
     @Parameter(defaultValue = "${mojoExecution}", readonly = true, required = true)
     private MojoExecution mojoExecution;
 
     @Parameter(defaultValue = "${project}", readonly = true, required = true)
     private MavenProject project;
 
     @Parameter(defaultValue = "${session}", readonly = true, required = true)
     private MavenSession session;
 
     @Parameter(defaultValue = "${settings}", readonly = true, required = true)
     private Settings settings;
 
     private final Invoker invoker;
 
     private final SettingsBuilder settingsBuilder;
 
     private final ToolchainManager toolchainManager;
 
     private final InterpolatorUtils interpolatorUtils;
 
     public AbstractInvokerMojo(
             Invoker invoker,
             SettingsBuilder settingsBuilder,
             ToolchainManager toolchainManagerPrivate,
             InterpolatorUtils interpolatorUtils) {
         this.invoker = invoker;
         this.settingsBuilder = settingsBuilder;
         this.toolchainManager = toolchainManagerPrivate;
         this.interpolatorUtils = interpolatorUtils;
     }
 
     public void setCloneProjectsTo(File cloneProjectsTo) {
 
         Boolean isNoneValue = Optional.ofNullable(cloneProjectsTo)
                 .filter(file -> !file.isDirectory())
                 .map(File::getName)
                 .map(name -> name.equalsIgnoreCase("none"))
                 .orElse(false);
 
         if (isNoneValue) {
             this.cloneProjectsTo = null;
         } else {
             this.cloneProjectsTo = cloneProjectsTo;
         }
     }
 
     /**
      * Invokes Maven on the configured test projects.
      *
      * @throws org.apache.maven.plugin.MojoExecutionException if the goal encountered severe errors
      * @throws org.apache.maven.plugin.MojoFailureException if any of the Maven builds failed
      */
     public void execute() throws MojoExecutionException, MojoFailureException {
         if (skipInvocation) {
             getLog().info("Skipping invocation per configuration."
                     + " If this is incorrect, ensure the skipInvocation parameter is not set to true.");
             return;
         }
 
         if (encoding == null || encoding.isEmpty()) {
             getLog().warn("File encoding has not been set, using platform encoding "
                     + Charset.defaultCharset().displayName() + ", i.e. build is platform dependent!");
         }
 
         // done it here to prevent issues with concurrent access in case of parallel run
         if (!disableReports) {
             setupReportsFolder();
         }
 
         List<BuildJob> buildJobs;
         if (pom == null) {
             try {
                 buildJobs = getBuildJobs();
             } catch (final IOException e) {
                 throw new MojoExecutionException(
                         "Error retrieving POM list from includes, " + "excludes, and projects directory. Reason: "
                                 + e.getMessage(),
                         e);
             }
         } else {
             try {
                 projectsDirectory = pom.getCanonicalFile().getParentFile();
             } catch (IOException e) {
                 throw new MojoExecutionException(
                         "Failed to discover projectsDirectory from " + "pom File parameter. Reason: " + e.getMessage(),
                         e);
             }
 
             buildJobs = Collections.singletonList(new BuildJob(pom.getName()));
         }
 
         if (buildJobs.isEmpty()) {
             doFailIfNoProjects();
 
             getLog().info("No projects were selected for execution.");
             return;
         }
 
         setupActualMavenVersion();
 
         handleScriptRunnerWithScriptClassPath();
 
         File projectsDir = projectsDirectory;
 
         if (cloneProjectsTo == null && "maven-plugin".equals(project.getPackaging())) {
             cloneProjectsTo = new File(project.getBuild().getDirectory(), "its");
         }
 
         if (updateOnly) {
             if (cloneProjectsTo == null) {
                 getLog().warn("updateOnly functionality is not supported without cloning the projects");
             } else if (lastModifiedRecursive(projectsDirectory) <= lastModifiedRecursive(cloneProjectsTo)) {
                 getLog().debug("Skipping invocation as cloned projects are up-to-date "
                         + "and updateOnly parameter is set to true.");
                 return;
             } else {
                 getLog().debug("Cloned projects are out of date");
             }
         }
 
         if (cloneProjectsTo != null) {
             Collection<String> collectedProjects = this.collectedProjects;
             if (collectedProjects == null) {
                 collectedProjects = new LinkedHashSet<>();
                 for (BuildJob buildJob : buildJobs) {
                     collectProjects(projectsDirectory, buildJob.getProject(), collectedProjects, true);
                 }
             }
             cloneProjects(collectedProjects);
             addMissingDotMvnDirectory(cloneProjectsTo, buildJobs);
             projectsDir = cloneProjectsTo;
         } else {
             getLog().warn("Filtering of parent/child POMs is not supported without cloning the projects");
         }
 
         // First run setup jobs.
         List<BuildJob> setupBuildJobs = getSetupJobs(buildJobs);
 
         if (!setupBuildJobs.isEmpty()) {
             // Run setup jobs in single thread mode.
             //
             // Jobs are ordered according to ordinal value from invoker.properties
             getLog().info("Running " + setupBuildJobs.size() + " setup job" + ((setupBuildJobs.size() < 2) ? "" : "s")
                     + ":");
             runBuildsWithRetry(projectsDir, setupBuildJobs, 1);
             getLog().info("Setup done.");
         }
 
         List<BuildJob> nonSetupBuildJobs = getNonSetupJobs(buildJobs);
 
         if (setupBuildJobs.isEmpty() || setupBuildJobs.stream().allMatch(BuildJob::isNotError)) {
             // We will run the non setup jobs with the configured
             // parallelThreads number.
             runBuildsWithRetry(projectsDir, nonSetupBuildJobs, getParallelThreadsCount());
         } else {
             for (BuildJob buildJob : nonSetupBuildJobs) {
                 buildJob.setResult(BuildJob.Result.SKIPPED);
                 buildJob.setFailureMessage("Skipped due to setup job(s) failure");
                 writeBuildReport(buildJob);
             }
         }
 
         writeSummaryFile(buildJobs);
         processResults(new InvokerSession(buildJobs));
     }
 
     void runBuildsWithRetry(File projectsDir, List<BuildJob> buildJobs, int runWithParallelThreads)
             throws MojoExecutionException {
         List<BuildJob> jobsToExecute = buildJobs;
         int executionCount = 0;
         do {
             if (executionCount > 0) {
                 getLog().warn("Rerunning " + jobsToExecute.size() + " failed job"
                         + ((jobsToExecute.size() < 2) ? "" : "s"));
             }
 
             executionCount++;
 
             // set current execution count for jobs
             for (BuildJob buildJob : jobsToExecute) {
                 buildJob.setExecutionCount(executionCount);
             }
 
             runBuilds(projectsDir, jobsToExecute, runWithParallelThreads);
             jobsToExecute = getFailedJobs(jobsToExecute);
             if (getLog().isDebugEnabled()) {
                 getLog().debug("Execution count: " + executionCount + ", failed jobs: "
                         + jobsToExecute.stream().map(BuildJob::getProject).collect(Collectors.joining(", ", "[", "]")));
             }
         } while (executionCount <= rerunFailingTestsCount && !jobsToExecute.isEmpty());
     }
 
     /**
      * We need add missing {@code .mnvn} directories for executing projects
      *
      * @param projectsDir base of projects
      * @param buildJobs list of discovered jobs
      */
     private void addMissingDotMvnDirectory(File projectsDir, List<BuildJob> buildJobs) throws MojoExecutionException {
         for (BuildJob buildJob : buildJobs) {
             Path projectPath = projectsDir.toPath().resolve(buildJob.getProject());
 
             if (Files.isRegularFile(projectPath)) {
                 projectPath = projectPath.getParent();
             }
 
             Path mvnDotPath = projectPath.resolve(".mvn");
             if (!Files.exists(mvnDotPath)) {
                 try {
                     Files.createDirectories(mvnDotPath);
                 } catch (IOException e) {
                     throw new MojoExecutionException(e.getMessage(), e);
                 }
             }
         }
     }
 
     private void setupActualMavenVersion() throws MojoExecutionException {
         if (mavenHome != null) {
             try {
                 actualMavenVersion = SelectorUtils.getMavenVersion(mavenHome);
             } catch (IOException e) {
                 throw new MojoExecutionException(e.getMessage(), e);
             }
         } else {
             actualMavenVersion = SelectorUtils.getMavenVersion();
         }
     }
 
     /**
      * Find the latest lastModified recursively within a directory structure.
      *
      * @param file the root file to check.
      * @return the latest lastModified time found.
      */
     private long lastModifiedRecursive(File file) {
         long lastModified = file.lastModified();
 
         final File[] entries = file.listFiles();
 
         if (entries != null) {
             for (File entry : entries) {
                 lastModified = Math.max(lastModified, lastModifiedRecursive(entry));
             }
         }
 
         return lastModified;
     }
 
     /**
      * This will create the necessary folders for the reports.
      *
      * @throws MojoExecutionException in case of failure during creation of the reports folder.
      */
     private void setupReportsFolder() throws MojoExecutionException {
         // If it exists from previous run...
         if (reportsDirectory.exists()) {
             try {
                 FileUtils.deleteDirectory(reportsDirectory);
             } catch (IOException e) {
                 throw new MojoExecutionException(
                         "Failure while trying to delete " + reportsDirectory.getAbsolutePath(), e);
             }
         }
         if (!reportsDirectory.mkdirs()) {
             throw new MojoExecutionException("Failure while creating the " + reportsDirectory.getAbsolutePath());
         }
     }
 
     private List<BuildJob> getSetupJobs(List<BuildJob> buildJobs) {
         return buildJobs.stream()
                 .filter(buildJob -> buildJob.getType().equals(BuildJob.Type.SETUP))
                 .collect(Collectors.toList());
     }
 
     private List<BuildJob> getNonSetupJobs(List<BuildJob> buildJobs) {
         return buildJobs.stream()
                 .filter(buildJob -> !buildJob.getType().equals(BuildJob.Type.SETUP))
                 .collect(Collectors.toList());
     }
 
     private List<BuildJob> getFailedJobs(List<BuildJob> buildJobs) {
         return buildJobs.stream().filter(buildJob -> !buildJob.isNotError()).collect(Collectors.toList());
     }
 
     private void handleScriptRunnerWithScriptClassPath() {
         final List<String> scriptClassPath;
         if (addTestClassPath) {
             scriptClassPath = new ArrayList<>(testClassPath);
             for (Artifact pluginArtifact : pluginArtifacts) {
                 scriptClassPath.remove(pluginArtifact.getFile().getAbsolutePath());
             }
         } else {
             scriptClassPath = null;
         }
         scriptRunner = new ScriptRunner();
         scriptRunner.setScriptEncoding(encoding);
         scriptRunner.setGlobalVariable("localRepositoryPath", localRepositoryPath);
         scriptRunner.setGlobalVariable("mavenVersion", actualMavenVersion);
         if (scriptVariables != null) {
             scriptVariables.forEach((key, value) -> scriptRunner.setGlobalVariable(key, value));
         }
         scriptRunner.setClassPath(scriptClassPath);
     }
 
     private void writeSummaryFile(List<BuildJob> buildJobs) throws MojoExecutionException {
 
         File summaryReportFile = new File(reportsDirectory, "invoker-summary.txt");
 
         try (Writer writer = new BufferedWriter(new FileWriter(summaryReportFile))) {
             for (BuildJob buildJob : buildJobs) {
                 if (!BuildJob.Result.SUCCESS.equals(buildJob.getResult())) {
                     writer.append(buildJob.getResult());
                     writer.append(" [");
                     writer.append(buildJob.getProject());
                     writer.append("] ");
                     if (buildJob.getFailureMessage() != null) {
                         writer.append(" ");
                         writer.append(buildJob.getFailureMessage());
                     }
                     writer.append("\n");
                 }
             }
         } catch (IOException e) {
             throw new MojoExecutionException("Failed to write summary report " + summaryReportFile, e);
         }
     }
 
     protected void doFailIfNoProjects() throws MojoFailureException {
         // should only be used during run and verify
     }
 
     /**
      * Processes the results of invoking the build jobs.
      *
      * @param invokerSession The session with the build jobs, must not be <code>null</code>.
      * @throws MojoFailureException If the mojo had failed as a result of invoking the build jobs.
      * @since 1.4
      */
     abstract void processResults(InvokerSession invokerSession) throws MojoFailureException;
 
     /**
      * Collects all projects locally reachable from the specified project. The method will as such try to read the POM
      * and recursively follow its parent/module elements.
      *
      * @param projectsDir The base directory of all projects, must not be <code>null</code>.
      * @param projectPath The relative path of the current project, can denote either the POM or its base directory,
      *            must not be <code>null</code>.
      * @param projectPaths The set of already collected projects to add new projects to, must not be <code>null</code>.
      *            This set will hold the relative paths to either a POM file or a project base directory.
      * @param included A flag indicating whether the specified project has been explicitly included via the parameter
      *            {@link #pomIncludes}. Such projects will always be added to the result set even if there is no
      *            corresponding POM.
      * @throws org.apache.maven.plugin.MojoExecutionException If the project tree could not be traversed.
      */
     private void collectProjects(
             File projectsDir, String projectPath, Collection<String> projectPaths, boolean included)
             throws MojoExecutionException {
         projectPath = projectPath.replace('\\', '/');
         File pomFile = new File(projectsDir, projectPath);
         if (pomFile.isDirectory()) {
             pomFile = new File(pomFile, "pom.xml");
             if (!pomFile.exists()) {
                 if (included) {
                     projectPaths.add(projectPath);
                 }
                 return;
             }
             if (!projectPath.endsWith("/")) {
                 projectPath += '/';
             }
             projectPath += "pom.xml";
         } else if (!pomFile.isFile()) {
             return;
         }
         if (!projectPaths.add(projectPath)) {
             return;
         }
         getLog().debug("Collecting parent/child projects of " + projectPath);
 
         Model model = PomUtils.loadPom(pomFile);
 
         try {
             String projectsRoot = projectsDir.getCanonicalPath();
             String projectDir = pomFile.getParent();
 
             String parentPath = "../pom.xml";
             if (model.getParent() != null && isNotEmpty(model.getParent().getRelativePath())) {
                 parentPath = model.getParent().getRelativePath();
             }
             String parent = relativizePath(new File(projectDir, parentPath), projectsRoot);
             if (parent != null) {
                 collectProjects(projectsDir, parent, projectPaths, false);
             }
 
             Collection<String> modulePaths = new LinkedHashSet<>(model.getModules());
 
             model.getProfiles().forEach(profile -> modulePaths.addAll(profile.getModules()));
 
             for (String modulePath : modulePaths) {
                 String module = relativizePath(new File(projectDir, modulePath), projectsRoot);
                 if (module != null) {
                     collectProjects(projectsDir, module, projectPaths, false);
                 }
             }
         } catch (IOException e) {
             throw new MojoExecutionException("Failed to analyze POM: " + pomFile, e);
         }
     }
 
     private boolean isNotEmpty(String s) {
         return Objects.nonNull(s) && !s.isEmpty();
     }
 
     /**
      * Copies the specified projects to the directory given by {@link #cloneProjectsTo}. A project may either be denoted
      * by a path to a POM file or merely by a path to a base directory. During cloning, the POM files will be filtered.
      *
      * @param projectPaths The paths to the projects to clone, relative to the projects directory, must not be
      *            <code>null</code> nor contain <code>null</code> elements.
      * @throws org.apache.maven.plugin.MojoExecutionException If the projects could not be copied/filtered.
      */
     private void cloneProjects(Collection<String> projectPaths) throws MojoExecutionException {
         if (!cloneProjectsTo.mkdirs() && cloneClean) {
             try {
                 FileUtils.cleanDirectory(cloneProjectsTo);
             } catch (IOException e) {
                 throw new MojoExecutionException(
                         "Could not clean the cloneProjectsTo directory. Reason: " + e.getMessage(), e);
             }
         }
 
         // determine project directories to clone
         Collection<String> dirs = new LinkedHashSet<>();
         for (String projectPath : projectPaths) {
             if (!new File(projectsDirectory, projectPath).isDirectory()) {
                 projectPath = getParentPath(projectPath);
             }
             dirs.add(projectPath);
         }
 
         boolean filter;
 
         // clone project directories
         try {
             filter = !cloneProjectsTo.getCanonicalFile().equals(projectsDirectory.getCanonicalFile());
 
             List<String> clonedSubpaths = new ArrayList<>();
 
             for (String subpath : dirs) {
                 // skip this project if its parent directory is also scheduled for cloning
                 if (!".".equals(subpath) && dirs.contains(getParentPath(subpath))) {
                     continue;
                 }
 
                 // avoid copying subdirs that are already cloned.
                 if (!alreadyCloned(subpath, clonedSubpaths)) {
                     // avoid creating new files that point to dir/.
                     if (".".equals(subpath)) {
                         String cloneSubdir = relativizePath(cloneProjectsTo, projectsDirectory.getCanonicalPath());
 
                         // avoid infinite recursion if the cloneTo path is a subdirectory.
                         if (cloneSubdir != null) {
                             File temp = Files.createTempDirectory("pre-invocation-clone.")
                                     .toFile();
 
                             copyDirectoryStructure(projectsDirectory, temp);
 
                             FileUtils.deleteDirectory(new File(temp, cloneSubdir));
 
                             copyDirectoryStructure(temp, cloneProjectsTo);
                         } else {
                             copyDirectoryStructure(projectsDirectory, cloneProjectsTo);
                         }
                     } else {
                         File srcDir = new File(projectsDirectory, subpath);
                         File dstDir = new File(cloneProjectsTo, subpath);
                         copyDirectoryStructure(srcDir, dstDir);
                     }
 
                     clonedSubpaths.add(subpath);
                 }
             }
         } catch (IOException e) {
             throw new MojoExecutionException(
                     "Failed to clone projects from: " + projectsDirectory + " to: " + cloneProjectsTo + ". Reason: "
                             + e.getMessage(),
                     e);
         }
 
         // filter cloned POMs
         if (filter) {
             for (String projectPath : projectPaths) {
                 File pomFile = new File(cloneProjectsTo, projectPath);
                 if (pomFile.isFile()) {
                     buildInterpolatedFile(pomFile, pomFile);
                 }
 
                 // MINVOKER-186
                 // The following is a temporary solution to support Maven 3.3.1 (.mvn/extensions.xml) filtering
                 // Will be replaced by MINVOKER-117 with general filtering mechanism
                 File baseDir = pomFile.getParentFile();
                 File mvnDir = new File(baseDir, ".mvn");
                 if (mvnDir.isDirectory()) {
                     File extensionsFile = new File(mvnDir, "extensions.xml");
                     if (extensionsFile.isFile()) {
                         buildInterpolatedFile(extensionsFile, extensionsFile);
                     }
                 }
                 // END MINVOKER-186
             }
             filteredPomPrefix = null;
         }
     }
 
     /**
      * Gets the parent path of the specified relative path.
      *
      * @param path The relative path whose parent should be retrieved, must not be <code>null</code>.
      * @return The parent path or "." if the specified path has no parent, never <code>null</code>.
      */
     private String getParentPath(String path) {
         int lastSep = Math.max(path.lastIndexOf('/'), path.lastIndexOf('\\'));
         return (lastSep < 0) ? "." : path.substring(0, lastSep);
     }
 
     /**
      * Copied a directory structure with default exclusions (.svn, CVS, etc)
      *
      * @param sourceDir The source directory to copy, must not be <code>null</code>.
      * @param destDir The target directory to copy to, must not be <code>null</code>.
      * @throws java.io.IOException If the directory structure could not be copied.
      */
     private void copyDirectoryStructure(File sourceDir, File destDir) throws IOException {
         DirectoryScanner scanner = new DirectoryScanner();
         scanner.setBasedir(sourceDir);
         if (!cloneAllFiles) {
             scanner.addDefaultExcludes();
         }
         scanner.scan();
 
         /*
          * NOTE: Make sure the destination directory is always there (even if empty) to support POM-less ITs.
          */
         Files.createDirectories(destDir.toPath());
         // Create all the directories, including any symlinks present in source
         FileUtils.mkDirs(sourceDir, scanner.getIncludedDirectories(), destDir);
 
         for (String includedFile : scanner.getIncludedFiles()) {
             File sourceFile = new File(sourceDir, includedFile);
             File destFile = new File(destDir, includedFile);
             if (NioFiles.isSymbolicLink(sourceFile)) {
                 NioFiles.createSymbolicLink(destFile, NioFiles.readSymbolicLink(sourceFile));
             } else {
                 FileUtils.copyFile(sourceFile, destFile);
             }
 
             // ensure clone project must be writable for additional changes
             destFile.setWritable(true);
         }
     }
 
     /**
      * Determines whether the specified sub path has already been cloned, i.e. whether one of its ancestor directories
      * was already cloned.
      *
      * @param subpath The sub path to check, must not be <code>null</code>.
      * @param clonedSubpaths The list of already cloned paths, must not be <code>null</code> nor contain
      *            <code>null</code> elements.
      * @return <code>true</code> if the specified path has already been cloned, <code>false</code> otherwise.
      */
     static boolean alreadyCloned(String subpath, List<String> clonedSubpaths) {
         for (String path : clonedSubpaths) {
             if (".".equals(path) || subpath.equals(path) || subpath.startsWith(path + File.separator)) {
                 return true;
             }
         }
 
         return false;
     }
 
     /**
      * Runs the specified build jobs.
      *
      * @param projectsDir The base directory of all projects, must not be <code>null</code>.
      * @param buildJobs The build jobs to run must not be <code>null</code> nor contain <code>null</code> elements.
      * @throws org.apache.maven.plugin.MojoExecutionException If any build could not be launched.
      */
     private void runBuilds(final File projectsDir, List<BuildJob> buildJobs, int runWithParallelThreads)
             throws MojoExecutionException {
         if (!localRepositoryPath.exists()) {
             localRepositoryPath.mkdirs();
         }
 
         // -----------------------------------------------
         // interpolate settings file
         // -----------------------------------------------
 
         File interpolatedSettingsFile = interpolateSettings(settingsFile);
 
         final File mergedSettingsFile = mergeSettings(interpolatedSettingsFile);
 
         final CharSequence actualJreVersion;
         // @todo if ( javaVersions ) ... to be picked up from toolchains
         if (javaHome != null) {
             actualJreVersion = resolveExternalJreVersion();
         } else {
             actualJreVersion = SelectorUtils.getJreVersion();
         }
 
         final Path projectsPath = this.projectsDirectory.toPath();
 
         Set<Path> folderGroupSet = new HashSet<>();
         folderGroupSet.add(Paths.get("."));
         for (BuildJob buildJob : buildJobs) {
             Path p = Paths.get(buildJob.getProject());
 
             if (Files.isRegularFile(projectsPath.resolve(p))) {
                 p = p.getParent();
             }
 
             if (p != null) {
                 p = p.getParent();
             }
 
             while (p != null && folderGroupSet.add(p)) {
                 p = p.getParent();
             }
         }
 
         List<Path> folderGroup = new ArrayList<>(folderGroupSet);
         Collections.sort(folderGroup);
 
         final Map<Path, Properties> globalInvokerProperties = new HashMap<>();
 
         for (Path path : folderGroup) {
             Properties ancestorProperties =
                     globalInvokerProperties.get(projectsPath.resolve(path).getParent());
 
             Path currentInvokerProperties = projectsPath.resolve(path).resolve(invokerPropertiesFile);
 
             Properties currentProperties;
             if (Files.isRegularFile(currentInvokerProperties)) {
                 if (ancestorProperties != null) {
                     currentProperties = new Properties(ancestorProperties);
 
                 } else {
                     currentProperties = new Properties();
                 }
             } else {
                 currentProperties = ancestorProperties;
             }
 
             if (Files.isRegularFile(currentInvokerProperties)) {
                 try (InputStream in = Files.newInputStream(currentInvokerProperties)) {
                     currentProperties.load(in);
                 } catch (IOException e) {
                     throw new MojoExecutionException("Failed to read invoker properties: " + currentInvokerProperties);
                 }
             }
 
             if (currentProperties != null) {
                 globalInvokerProperties.put(projectsPath.resolve(path).normalize(), currentProperties);
             }
         }
 
         try {
             if (runWithParallelThreads > 1) {
                 getLog().info("use parallelThreads " + runWithParallelThreads);
             }
 
             JobExecutor jobExecutor = new JobExecutor(buildJobs, runWithParallelThreads);
             jobExecutor.forEach(job -> {
                 Path ancestorFolder = getAncestorFolder(projectsPath.resolve(job.getProject()));
 
                 runBuild(
                         projectsDir,
                         job,
                         mergedSettingsFile,
                         javaHome,
                         actualJreVersion,
                         globalInvokerProperties.get(ancestorFolder));
             });
         } finally {
             if (interpolatedSettingsFile != null && cloneProjectsTo == null) {
                 interpolatedSettingsFile.delete();
             }
             if (mergedSettingsFile != null && mergedSettingsFile.exists()) {
                 mergedSettingsFile.delete();
             }
         }
     }
 
     private Path getAncestorFolder(Path p) {
         Path ancestor = p;
         if (Files.isRegularFile(ancestor)) {
             ancestor = ancestor.getParent();
         }
         if (ancestor != null) {
             ancestor = ancestor.getParent();
         }
         return ancestor;
     }
 
     /**
      * Interpolate settings.xml file.
      * @param settingsFile a settings file
      *
      * @return The interpolated settings.xml file.
      * @throws MojoExecutionException in case of a problem.
      */
     private File interpolateSettings(File settingsFile) throws MojoExecutionException {
         File interpolatedSettingsFile = null;
         if (settingsFile != null) {
             if (cloneProjectsTo != null) {
                 interpolatedSettingsFile = new File(cloneProjectsTo, "interpolated-" + settingsFile.getName());
             } else {
                 interpolatedSettingsFile =
                         new File(settingsFile.getParentFile(), "interpolated-" + settingsFile.getName());
             }
             buildInterpolatedFile(settingsFile, interpolatedSettingsFile);
         }
         return interpolatedSettingsFile;
     }
 
     /**
      * Merge the settings file
      *
      * @param interpolatedSettingsFile The interpolated settings file.
      * @return The merged settings file.
      * @throws MojoExecutionException Fail the build in case the merged settings file can't be created.
      */
     private File mergeSettings(File interpolatedSettingsFile) throws MojoExecutionException {
         File mergedSettingsFile;
         Settings mergedSettings = this.settings;
         if (mergeUserSettings) {
             if (interpolatedSettingsFile != null) {
                 // Have to merge the specified settings file (dominant) and the one of the invoking Maven process
                 try {
                     SettingsBuildingRequest request = new DefaultSettingsBuildingRequest();
                     request.setGlobalSettingsFile(interpolatedSettingsFile);
 
                     Settings dominantSettings = settingsBuilder.build(request).getEffectiveSettings();
                     Settings recessiveSettings = cloneSettings();
                     SettingsUtils.merge(dominantSettings, recessiveSettings, TrackableBase.USER_LEVEL);
 
                     mergedSettings = dominantSettings;
                     getLog().debug("Merged specified settings file with settings of invoking process");
                 } catch (SettingsBuildingException e) {
                     throw new MojoExecutionException("Could not read specified settings file", e);
                 }
             }
         }
 
         if (this.settingsFile != null && !mergeUserSettings) {
             mergedSettingsFile = interpolatedSettingsFile;
         } else {
             try {
                 mergedSettingsFile = writeMergedSettingsFile(mergedSettings);
             } catch (IOException e) {
                 throw new MojoExecutionException("Could not create temporary file for invoker settings.xml", e);
             }
         }
         return mergedSettingsFile;
     }
 
     private File writeMergedSettingsFile(Settings mergedSettings) throws IOException {
         File mergedSettingsFile;
         mergedSettingsFile = Files.createTempFile("invoker-settings", ".xml").toFile();
 
         SettingsXpp3Writer settingsWriter = new SettingsXpp3Writer();
 
         try (FileWriter fileWriter = new FileWriter(mergedSettingsFile)) {
             settingsWriter.write(fileWriter, mergedSettings);
         }
 
         if (getLog().isDebugEnabled()) {
             getLog().debug("Created temporary file for invoker settings.xml: " + mergedSettingsFile.getAbsolutePath());
         }
         return mergedSettingsFile;
     }
 
     private Settings cloneSettings() {
         Settings recessiveSettings = SettingsUtils.copySettings(this.settings);
 
         // MINVOKER-133: reset sourceLevelSet
         resetSourceLevelSet(recessiveSettings);
         for (org.apache.maven.settings.Mirror mirror : recessiveSettings.getMirrors()) {
             resetSourceLevelSet(mirror);
         }
         for (org.apache.maven.settings.Server server : recessiveSettings.getServers()) {
             resetSourceLevelSet(server);
         }
         for (org.apache.maven.settings.Proxy proxy : recessiveSettings.getProxies()) {
             resetSourceLevelSet(proxy);
         }
         for (org.apache.maven.settings.Profile profile : recessiveSettings.getProfiles()) {
             resetSourceLevelSet(profile);
         }
 
         return recessiveSettings;
     }
 
     private void resetSourceLevelSet(org.apache.maven.settings.TrackableBase trackable) {
         try {
             ReflectionUtils.setVariableValueInObject(trackable, "sourceLevelSet", Boolean.FALSE);
             getLog().debug("sourceLevelSet: "
                     + ReflectionUtils.getValueIncludingSuperclasses("sourceLevelSet", trackable));
         } catch (IllegalAccessException e) {
             // noop
         }
     }
 
     private CharSequence resolveExternalJreVersion() {
         Artifact pluginArtifact =
                 mojoExecution.getMojoDescriptor().getPluginDescriptor().getPluginArtifact();
         pluginArtifact.getFile();
 
         Commandline commandLine = new Commandline();
         commandLine.setExecutable(new File(javaHome, "bin/java").getAbsolutePath());
         commandLine.createArg().setValue("-cp");
         commandLine.createArg().setFile(pluginArtifact.getFile());
         commandLine.createArg().setValue(SystemPropertyPrinter.class.getName());
         commandLine.createArg().setValue("java.version");
 
         final StringBuilder actualJreVersion = new StringBuilder();
         StreamConsumer consumer = actualJreVersion::append;
         try {
             CommandLineUtils.executeCommandLine(commandLine, consumer, null);
         } catch (CommandLineException e) {
             getLog().warn(e.getMessage());
         }
         return actualJreVersion;
     }
 
     /**
      * Interpolate the pom file.
      *
      * @param pomFile The pom file.
      * @param basedir The base directory.
      * @return interpolated pom file location in case we have interpolated the pom file otherwise the original pom file
      *         will be returned.
      * @throws MojoExecutionException
      */
     private File interpolatePomFile(File pomFile, File basedir) throws MojoExecutionException {
         File interpolatedPomFile = null;
         if (pomFile != null) {
             if (filteredPomPrefix != null && !filteredPomPrefix.isEmpty()) {
                 interpolatedPomFile = new File(basedir, filteredPomPrefix + pomFile.getName());
                 buildInterpolatedFile(pomFile, interpolatedPomFile);
             } else {
                 interpolatedPomFile = pomFile;
             }
         }
         return interpolatedPomFile;
     }
 
     /**
      * Runs the specified project.
      *
      * @param projectsDir The base directory of all projects, must not be <code>null</code>.
      * @param buildJob The build job to run, must not be <code>null</code>.
      * @param settingsFile The (already interpolated) user settings file for the build, may be <code>null</code> to use
      *            the current user settings.
      * @param globalInvokerProperties
      * @throws org.apache.maven.plugin.MojoExecutionException If the project could not be launched.
      */
     private void runBuild(
             File projectsDir,
             BuildJob buildJob,
             File settingsFile,
             File actualJavaHome,
             CharSequence actualJreVersion,
             Properties globalInvokerProperties)
             throws MojoExecutionException {
         // FIXME: Think about the following code part -- START
         File pomFile = new File(projectsDir, buildJob.getProject());
         File basedir;
         if (pomFile.isDirectory()) {
             basedir = pomFile;
             pomFile = new File(basedir, "pom.xml");
             if (!pomFile.exists()) {
                 pomFile = null;
             } else {
                 buildJob.setProject(buildJob.getProject() + File.separator + "pom.xml");
             }
         } else {
             basedir = pomFile.getParentFile();
         }
 
         File interpolatedPomFile = interpolatePomFile(pomFile, basedir);
         // FIXME: Think about the following code part -- ^^^^^^^ END
 
         getLog().info(buffer().a("Building: ").strong(buildJob.getProject()).build());
 
         InvokerProperties invokerProperties = getInvokerProperties(basedir, globalInvokerProperties);
 
         // let's set what details we can
         buildJob.setName(invokerProperties.getJobName());
         buildJob.setDescription(invokerProperties.getJobDescription());
 
         try {
             int selection = getSelection(invokerProperties, actualJreVersion);
             if (selection == 0) {
                 long startTime = System.currentTimeMillis();
                 boolean executed;
 
                 FileLogger buildLogger = setupBuildLogFile(basedir, buildJob.getExecutionCount());
                 if (buildLogger != null) {
                     buildJob.setBuildlog(buildLogger.getOutputFile().getAbsolutePath());
                 }
 
                 try {
                     executed = runBuild(
                             basedir, interpolatedPomFile, settingsFile, actualJavaHome, invokerProperties, buildLogger);
                 } finally {
                     long elapsedTime = System.currentTimeMillis() - startTime;
                     buildJob.setTime(elapsedTime / ONE_SECOND);
 
                     if (buildLogger != null) {
                         buildLogger.close();
                     }
                 }
 
                 if (executed) {
                     buildJob.setResult(BuildJob.Result.SUCCESS);
                     buildJob.setFailureMessage(null);
 
                     if (!suppressSummaries) {
                         getLog().info(pad(buildJob).success("SUCCESS").a(' ') + "("
                                 + formatElapsedTime(buildJob.getTime()) + ")");
                     }
                 } else {
                     buildJob.setResult(BuildJob.Result.SKIPPED);
 
                     if (!suppressSummaries) {
                         getLog().info(pad(buildJob).warning("SKIPPED").a(' ') + "("
                                 + formatElapsedTime(buildJob.getTime()) + ")");
                     }
                 }
             } else {
                 buildJob.setResult(BuildJob.Result.SKIPPED);
 
                 List<String> messages = new ArrayList<>();
 
                 if (selection == Selector.SELECTOR_MULTI) {
                     messages.add("non-matching selectors");
                 } else {
                     if ((selection & Selector.SELECTOR_MAVENVERSION) != 0) {
                         messages.add("Maven version");
                     }
                     if ((selection & Selector.SELECTOR_JREVERSION) != 0) {
                         messages.add("JRE version");
                     }
                     if ((selection & Selector.SELECTOR_OSFAMILY) != 0) {
                         messages.add("OS");
                     }
                     if ((selection & Selector.SELECTOR_TOOLCHAIN) != 0) {
                         messages.add("Toolchain");
                     }
                 }
 
                 String message = String.join(", ", messages);
                 if (!suppressSummaries) {
                     getLog().info(pad(buildJob).warning("SKIPPED") + " due to " + message);
                 }
 
                 // Abuse failureMessage, the field in the report which should contain the reason for skipping
                 // Consider skipCode + I18N
                 buildJob.setFailureMessage("Skipped due to " + message);
             }
         } catch (RunFailureException e) {
             buildJob.setResult(e.getType());
             buildJob.setFailureMessage(e.getMessage());
 
             if (!suppressSummaries) {
                 getLog().info("  " + e.getMessage());
                 getLog().info(pad(buildJob).failure("FAILED").a(' ') + "(" + formatElapsedTime(buildJob.getTime())
                         + ")");
             }
         } finally {
             deleteInterpolatedPomFile(interpolatedPomFile);
             writeBuildReport(buildJob);
         }
     }
 
     private MessageBuilder pad(BuildJob buildJob) {
         MessageBuilder buffer = buffer(128);
 
         buffer.a("          ");
         buffer.a(buildJob.getProject());
 
         int l = 10 + buildJob.getProject().length();
 
         if (l < RESULT_COLUMN) {
             buffer.a(' ');
             l++;
 
             if (l < RESULT_COLUMN) {
                 for (int i = RESULT_COLUMN - l; i > 0; i--) {
                     buffer.a('.');
                 }
             }
         }
 
         return buffer.a(' ');
     }
 
     /**
      * Delete the interpolated pom file if it has been created before.
      *
      * @param interpolatedPomFile The interpolated pom file.
      */
     private void deleteInterpolatedPomFile(File interpolatedPomFile) {
         if (interpolatedPomFile != null && (filteredPomPrefix != null && !filteredPomPrefix.isEmpty())) {
             interpolatedPomFile.delete();
         }
     }
 
     /**
      * Determines whether selector conditions of the specified invoker properties match the current environment.
      *
      * @param invokerProperties The invoker properties to check, must not be <code>null</code>.
      * @return <code>0</code> if the job corresponding to the properties should be run, otherwise a bitwise value
      *         representing the reason why it should be skipped.
      */
     private int getSelection(InvokerProperties invokerProperties, CharSequence actualJreVersion) {
         return new Selector(actualMavenVersion, actualJreVersion.toString(), getToolchainPrivateManager())
                 .getSelection(invokerProperties);
     }
 
     private ToolchainPrivateManager getToolchainPrivateManager() {
         return new ToolchainPrivateManager(toolchainManager, session);
     }
 
     /**
      * Writes the XML report for the specified build job unless report generation has been disabled.
      *
      * @param buildJob The build job whose report should be written, must not be <code>null</code>.
      * @throws org.apache.maven.plugin.MojoExecutionException If the report could not be written.
      */
     private void writeBuildReport(BuildJob buildJob) throws MojoExecutionException {
         if (disableReports) {
             return;
         }
 
         String safeFileName =
                 buildJob.getProject().replace('/', '_').replace('\\', '_').replace(' ', '_');
         if (safeFileName.endsWith("_pom.xml")) {
             safeFileName = safeFileName.substring(0, safeFileName.length() - "_pom.xml".length());
         }
 
         File reportFile = new File(reportsDirectory, "BUILD-" + safeFileName + ".xml");
         try (FileOutputStream fos = new FileOutputStream(reportFile);
                 Writer osw = new OutputStreamWriter(fos, buildJob.getModelEncoding())) {
             BuildJobXpp3Writer writer = new BuildJobXpp3Writer();
 
             writer.write(osw, buildJob);
         } catch (IOException e) {
             throw new MojoExecutionException("Failed to write build report " + reportFile, e);
         }
 
         if (writeJunitReport) {
             writeJunitReport(buildJob, safeFileName);
         }
     }
 
     private void writeJunitReport(BuildJob buildJob, String safeFileName) throws MojoExecutionException {
         File reportFile = new File(reportsDirectory, "TEST-" + safeFileName + ".xml");
         Xpp3Dom testsuite = new Xpp3Dom("testsuite");
         testsuite.setAttribute("name", junitPackageName + "." + safeFileName);
         testsuite.setAttribute("time", Float.toString(buildJob.getTime()));
 
         // set default value for required attributes
         testsuite.setAttribute("tests", "1");
         testsuite.setAttribute("errors", "0");
         testsuite.setAttribute("skipped", "0");
         testsuite.setAttribute("failures", "0");
 
         Xpp3Dom testcase = new Xpp3Dom("testcase");
         testsuite.addChild(testcase);
         switch (buildJob.getResult()) {
             case BuildJob.Result.SUCCESS:
                 break;
             case BuildJob.Result.SKIPPED:
                 testsuite.setAttribute("skipped", "1");
                 // adding the failure element
                 Xpp3Dom skipped = new Xpp3Dom("skipped");
                 testcase.addChild(skipped);
                 skipped.setValue(buildJob.getFailureMessage());
                 break;
             case BuildJob.Result.ERROR:
                 testsuite.setAttribute("errors", "1");
                 break;
             default:
                 testsuite.setAttribute("failures", "1");
                 // adding the failure element
                 Xpp3Dom failure = new Xpp3Dom("failure");
                 testcase.addChild(failure);
                 failure.setAttribute("message", buildJob.getFailureMessage());
         }
         testcase.setAttribute("classname", junitPackageName + "." + safeFileName);
         testcase.setAttribute("name", safeFileName);
         testcase.setAttribute("time", Float.toString(buildJob.getTime()));
         Xpp3Dom systemOut = new Xpp3Dom("system-out");
         testcase.addChild(systemOut);
 
         File buildLogFile = buildJob.getBuildlog() != null ? new File(buildJob.getBuildlog()) : null;
 
         if (buildLogFile != null && buildLogFile.exists()) {
             getLog().debug("fileLogger:" + buildLogFile);
             try {
                 systemOut.setValue(FileUtils.fileRead(buildLogFile));
             } catch (IOException e) {
                 throw new MojoExecutionException("Failed to read logfile " + buildLogFile, e);
             }
         } else {
             getLog().debug(safeFileName + "not exists buildLogFile = " + buildLogFile);
         }
 
         try (FileOutputStream fos = new FileOutputStream(reportFile);
                 Writer osw = new OutputStreamWriter(fos, buildJob.getModelEncoding())) {
             Xpp3DomWriter.write(osw, testsuite);
         } catch (IOException e) {
             throw new MojoExecutionException("Failed to write JUnit build report " + reportFile, e);
         }
     }
 
     /**
      * Formats the specified elapsed time.
      *
      * @param time The eapsed time of the build.
      * @return The formatted time, never <code>null</code>.
      */
     private String formatElapsedTime(float time) {
         /*
          * Rationale: The idea is to always display four digits for visually consistent output
          * Important: Keep in sync with src/main/resources/invoker-report.properties
          */
         final MessageFormat elapsedTimeFormat = new MessageFormat(
                 "{0,choice,0#0|0.0<{0,number,0.000}|10#{0,number,0.00}|100#{0,number,0.0}|1000#{0,number,0}} s",
                 Locale.ROOT);
         return elapsedTimeFormat.format(new Object[] {time});
     }
 
     /**
      * Runs the specified project.
      *
      * @param basedir The base directory of the project, must not be <code>null</code>.
      * @param pomFile The (already interpolated) POM file, may be <code>null</code> for a POM-less Maven invocation.
      * @param settingsFile The (already interpolated) user settings file for the build, may be <code>null</code>. Will
      *            be merged with the settings file of the invoking Maven process.
      * @param invokerProperties The properties to use.
      * @param logger file logger to write execution build.log
      * @return <code>true</code> if the project was launched or <code>false</code> if the selector script indicated that
      *         the project should be skipped.
      * @throws org.apache.maven.plugin.MojoExecutionException If the project could not be launched.
      * @throws RunFailureException If either a hook script or the build itself
      *             failed.
      */
     private boolean runBuild(
             File basedir,
             File pomFile,
             File settingsFile,
             File actualJavaHome,
             InvokerProperties invokerProperties,
             FileLogger logger)
             throws MojoExecutionException, RunFailureException {
         if (getLog().isDebugEnabled() && !invokerProperties.getProperties().isEmpty()) {
             Properties props = invokerProperties.getProperties();
             getLog().debug("Using invoker properties:");
             for (String key : new TreeSet<>(props.stringPropertyNames())) {
                 String value = props.getProperty(key);
                 getLog().debug("  " + key + " = " + value);
             }
         }
 
         Map<String, Object> context = new LinkedHashMap<>();
         Properties scriptUserProperties = new Properties();
         context.put("userProperties", scriptUserProperties);
 
         if (!runSelectorHook(basedir, context, logger)) {
             return false;
         }
 
         try {
             runPreBuildHook(basedir, context, logger, 0);
 
             for (int invocationIndex = 1; ; invocationIndex++) {
                 if (invocationIndex > 1 && !invokerProperties.isInvocationDefined(invocationIndex)) {
                     break;
                 }
 
                 runPreBuildHook(basedir, context, logger, invocationIndex);
 
                 final InvocationRequest request = new DefaultInvocationRequest();
 
                 request.setBatchMode(true);
 
                 // values only from Mojo configurations
                 request.setLocalRepositoryDirectory(localRepositoryPath);
                 request.setShowErrors(showErrors);
                 request.setShowVersion(showVersion);
                 request.setJavaHome(actualJavaHome);
                 request.setMavenHome(mavenHome);
                 setupLoggerForBuildJob(logger, request);
 
                 request.setBaseDirectory(basedir);
                 request.setPomFile(pomFile);
 
                 String customSettingsFile = invokerProperties.getSettingsFile(invocationIndex);
                 if (customSettingsFile != null) {
                     File interpolateSettingsFile = interpolateSettings(new File(customSettingsFile));
                     File mergeSettingsFile = mergeSettings(interpolateSettingsFile);
 
                     request.setUserSettingsFile(mergeSettingsFile);
                 } else {
                     request.setUserSettingsFile(settingsFile);
                 }
 
                 Properties userProperties =
                         getUserProperties(basedir, invokerProperties.getUserPropertiesFile(invocationIndex));
                 userProperties.putAll(scriptUserProperties);
                 request.setProperties(userProperties);
 
                 invokerProperties.configureInvocation(request, invocationIndex);
 
                 if (getLog().isDebugEnabled()) {
                     try {
                         getLog().debug("Using MAVEN_OPTS: " + request.getMavenOpts());
                         getLog().debug("Executing: " + new MavenCommandLineBuilder().build(request));
                     } catch (CommandLineConfigurationException e) {
                         getLog().debug("Failed to display command line: " + e.getMessage());
                     }
                 }
 
                 try {
                     InvocationResult result = invoker.execute(request);
                     verify(result, invocationIndex, invokerProperties, logger);
                 } catch (final MavenInvocationException e) {
                     getLog().debug("Error invoking Maven: " + e.getMessage(), e);
                     throw new RunFailureException(
                             "Maven invocation failed. " + e.getMessage(), BuildJob.Result.FAILURE_BUILD);
                 }
                 runPostBuildHook(basedir, context, logger, invocationIndex);
             }
         } finally {
             runPostBuildHook(basedir, context, logger, 0);
         }
         return true;
     }
 
     int getParallelThreadsCount() {
         if (parallelThreads.endsWith("C")) {
             float parallelThreadsMultiple =
                     Float.parseFloat(parallelThreads.substring(0, parallelThreads.length() - 1));
             return (int) (parallelThreadsMultiple * Runtime.getRuntime().availableProcessors());
         } else {
             return Integer.parseInt(parallelThreads);
         }
     }
 
     private boolean runSelectorHook(File basedir, Map<String, Object> context, FileLogger logger)
             throws MojoExecutionException, RunFailureException {
         try {
             scriptRunner.run("selector script", basedir, selectorScript, context, logger);
         } catch (ScriptReturnException e) {
             return false;
         } catch (ScriptException e) {
             if (logger != null) {
                 logger.consumeLine("Error executing selector script: " + e.getMessage());
             }
             throw new RunFailureException(BuildJob.Result.ERROR, e);
         } catch (IOException e) {
             throw new MojoExecutionException(e.getMessage(), e);
         }
         return true;
     }
 
     private void runPreBuildHook(File basedir, Map<String, Object> context, FileLogger logger, int invocationIndex)
             throws MojoExecutionException, RunFailureException {
         try {
             String hookName = invocationIndex > 0 ? preBuildHookScript + "." + invocationIndex : preBuildHookScript;
             scriptRunner.run("pre-build script", basedir, hookName, context, logger);
         } catch (ScriptException e) {
             if (logger != null) {
                 logger.consumeLine("Error executing pre-build hook: " + e.getMessage());
             }
             throw new RunFailureException(BuildJob.Result.FAILURE_PRE_HOOK, e);
         } catch (IOException e) {
             throw new MojoExecutionException(e.getMessage(), e);
         }
     }
 
     private void runPostBuildHook(File basedir, Map<String, Object> context, FileLogger logger, int invocationIndex)
             throws MojoExecutionException, RunFailureException {
         try {
             String hookName = invocationIndex > 0 ? postBuildHookScript + "." + invocationIndex : postBuildHookScript;
             scriptRunner.run("post-build script", basedir, hookName, context, logger);
         } catch (IOException e) {
             throw new MojoExecutionException(e.getMessage(), e);
         } catch (ScriptException e) {
             if (logger != null) {
                 logger.consumeLine("Error executing post-build hook: " + e.getMessage());
             }
             throw new RunFailureException(e.getMessage(), BuildJob.Result.FAILURE_POST_HOOK, e);
         }
     }
 
     private void setupLoggerForBuildJob(final FileLogger logger, final InvocationRequest request) {
         if (logger != null) {
             request.setErrorHandler(logger);
             request.setOutputHandler(logger);
         }
     }
 
     /**
      * Initializes the build logger for the specified project. This will write the logging information into
      * {@code build.log}.
      *
      * @param basedir The base directory of the project, must not be <code>null</code>.
      * @param executionCount current execution count of the build job, used to determine whether to append to or create a new log file
      * @return The build logger or <code>null</code> if logging has been disabled.
      * @throws org.apache.maven.plugin.MojoExecutionException If the log file could not be created.
      */
     private FileLogger setupBuildLogFile(File basedir, int executionCount) throws MojoExecutionException {
         FileLogger logger = null;
 
         if (!noLog) {
             Path projectLogDirectory;
             if (logDirectory == null) {
                 projectLogDirectory = basedir.toPath();
             } else if (cloneProjectsTo != null) {
                 projectLogDirectory =
                         logDirectory.toPath().resolve(cloneProjectsTo.toPath().relativize(basedir.toPath()));
             } else {
                 projectLogDirectory =
                         logDirectory.toPath().resolve(projectsDirectory.toPath().relativize(basedir.toPath()));
             }
 
             Log streamLogger = streamLogs ? getLog() : null;
             Path logPath = projectLogDirectory.resolve("build.log");
 
             try {
                 if (executionCount > 1 && Files.exists(logPath)) {
                     // next execution, rename log file from build.log to build-<executionCount -1 >.log
                     // we preserve log from previous execution, and start with new log file for current execution
                     // each execution should have new log file as many assertions check string presence in log file, a
                     // nd if we keep appending to same log file, it will be hard to determine which log entry belongs to
                     // which execution
                     Path logFileBackup =
                             logPath.getParent().resolve(logPath.getFileName().toString() + "." + (executionCount - 1));
                     getLog().debug("Renaming existing log file " + logPath + " to " + logFileBackup);
                     Files.move(logPath, logFileBackup, StandardCopyOption.REPLACE_EXISTING);
                 }
                 logger = new FileLogger(logPath.toFile(), streamLogger);
                 getLog().debug("New build log initialized: " + logPath);
             } catch (IOException e) {
                 throw new MojoExecutionException("Error initializing build logfile in: " + projectLogDirectory, e);
             }
         }
 
         return logger;
     }
 
     /**
      * Gets the system properties to use for the specified project.
      *
      * @param basedir The base directory of the project, must not be <code>null</code>.
      * @param filename The filename to the properties file to load, may be <code>null</code> to use the default path
      *            given by {@link #testPropertiesFile}.
      * @return The system properties to use, may be empty but never <code>null</code>.
      * @throws org.apache.maven.plugin.MojoExecutionException If the properties file exists but could not be read.
      */
     private Properties getUserProperties(final File basedir, final String filename) throws MojoExecutionException {
         Properties collectedTestProperties = new Properties();
 
         if (properties != null) {
             // MINVOKER-118: property can have empty value, which is not accepted by collectedTestProperties
             for (Map.Entry<String, String> entry : properties.entrySet()) {
                 if (entry.getValue() != null) {
                     collectedTestProperties.put(entry.getKey(), entry.getValue());
                 }
             }
         }
 
         File propertiesFile = null;
         if (filename != null) {
             propertiesFile = new File(basedir, filename);
         }
 
         if (propertiesFile != null && propertiesFile.isFile()) {
 
             try (InputStream fin = Files.newInputStream(propertiesFile.toPath())) {
                 Properties loadedProperties = new Properties();
                 loadedProperties.load(fin);
                 collectedTestProperties.putAll(loadedProperties);
             } catch (IOException e) {
                 throw new MojoExecutionException("Error reading user properties from " + propertiesFile);
             }
         }
 
         return collectedTestProperties;
     }
 
     /**
      * Verifies the invocation result.
      *
      * @param result The invocation result to check, must not be <code>null</code>.
      * @param invocationIndex The index of the invocation for which to check the exit code, must not be negative.
      * @param invokerProperties The invoker properties used to check the exit code, must not be <code>null</code>.
      * @param logger The build logger, may be <code>null</code> if logging is disabled.
      */
     private void verify(
             InvocationResult result, int invocationIndex, InvokerProperties invokerProperties, FileLogger logger)
             throws RunFailureException {
         if (result.getExecutionException() != null) {
             throw new RunFailureException(
                     "The Maven invocation failed. "
                             + result.getExecutionException().getMessage(),
                     BuildJob.Result.ERROR);
         } else if (!invokerProperties.isExpectedResult(result.getExitCode(), invocationIndex)) {
             StringBuilder buffer = new StringBuilder(256);
             buffer.append("The build exited with code ")
                     .append(result.getExitCode())
                     .append(". ");
             if (logger != null) {
                 buffer.append("See ");
                 buffer.append(logger.getOutputFile().getAbsolutePath());
                 buffer.append(" for details.");
             } else {
                 buffer.append("See console output for details.");
             }
             throw new RunFailureException(buffer.toString(), BuildJob.Result.FAILURE_BUILD);
         }
     }
 
     private List<String> calculateIncludes() {
         if (invokerTest != null) {
             String[] testRegexes = invokerTest.split(",+");
             return Arrays.stream(testRegexes)
                     .map(String::trim)
                     .filter(s -> !s.isEmpty())
                     .filter(s -> !s.startsWith("!"))
                     .collect(Collectors.toList());
         } else {
             Set<String> uniqueIncludes = new HashSet<>();
             uniqueIncludes.addAll(pomIncludes);
             uniqueIncludes.addAll(setupIncludes);
             return new ArrayList<>(uniqueIncludes);
         }
     }
 
     private List<String> calculateExcludes() throws IOException {
         List<String> excludes;
 
         if (invokerTest != null) {
             String[] testRegexes = invokerTest.split(",+");
             excludes = Arrays.stream(testRegexes)
                     .map(String::trim)
                     .filter(s -> !s.isEmpty())
                     .filter(s -> s.startsWith("!"))
                     .map(s -> s.substring(1))
                     .collect(Collectors.toList());
         } else {
             excludes = pomExcludes != null ? new ArrayList<>(pomExcludes) : new ArrayList<>();
         }
 
         if (this.settingsFile != null) {
             String exclude = relativizePath(this.settingsFile, projectsDirectory.getCanonicalPath());
             if (exclude != null) {
                 excludes.add(exclude.replace('\\', '/'));
                 getLog().debug("Automatically excluded " + exclude + " from project scanning");
             }
         }
         return excludes;
     }
 
     /**
      * Gets the build jobs that should be processed. Note that the order of the returned build jobs is significant.
      *
      * @return The build jobs to process, may be empty but never <code>null</code>.
      * @throws java.io.IOException If the projects directory could not be scanned.
      */
     List<BuildJob> getBuildJobs() throws IOException, MojoExecutionException {
 
         List<String> includes = calculateIncludes();
         List<String> excludes = calculateExcludes();
         List<BuildJob> buildJobsAll = scanProjectsDirectory(includes, excludes);
         List<BuildJob> buildJobsSetup = scanProjectsDirectory(setupIncludes, excludes);
 
         List<String> setupProjects =
                 buildJobsSetup.stream().map(BuildJob::getProject).collect(Collectors.toList());
 
         for (BuildJob job : buildJobsAll) {
             if (setupProjects.contains(job.getProject())) {
                 job.setType(BuildJob.Type.SETUP);
             }
             InvokerProperties invokerProperties =
                     getInvokerProperties(new File(projectsDirectory, job.getProject()).getParentFile(), null);
             job.setOrdinal(invokerProperties.getOrdinal());
         }
 
         relativizeProjectPaths(buildJobsAll);
 
         return buildJobsAll;
     }
 
     /**
      * Scans the projects directory for projects to build. Both (POM) files and mere directories will be matched by the
      * scanner patterns. If the patterns match a directory which contains a file named "pom.xml", the results will
      * include the path to this file rather than the directory path in order to avoid duplicate invocations of the same
      * project.
      *
      * @param includes The include patterns for the scanner, may be <code>null</code>.
      * @param excludes The exclude patterns for the scanner, may be <code>null</code> to exclude nothing.
      * @return The build jobs matching the patterns, never <code>null</code>.
      * @throws java.io.IOException If the project directory could not be scanned.
      */
     private List<BuildJob> scanProjectsDirectory(List<String> includes, List<String> excludes) throws IOException {
         if (!projectsDirectory.isDirectory()) {
             return Collections.emptyList();
         }
 
         DirectoryScanner scanner = new DirectoryScanner();
         scanner.setBasedir(projectsDirectory.getCanonicalFile());
         scanner.setFollowSymlinks(false);
         if (includes != null) {
             scanner.setIncludes(includes.toArray(new String[0]));
         }
         if (excludes != null) {
             if ((includes == null || includes.isEmpty()) && !excludes.isEmpty()) {
                 scanner.setIncludes(new String[] {"*"});
             }
             scanner.setExcludes(excludes.toArray(new String[0]));
         }
         scanner.addDefaultExcludes();
         scanner.scan();
 
         Map<String, BuildJob> matches = new LinkedHashMap<>();
 
         for (String includedFile : scanner.getIncludedFiles()) {
             matches.put(includedFile, new BuildJob(includedFile));
         }
 
         for (String includedDir : scanner.getIncludedDirectories()) {
             String includedFile = includedDir + File.separatorChar + "pom.xml";
             if (new File(scanner.getBasedir(), includedFile).isFile()) {
                 matches.put(includedFile, new BuildJob(includedFile));
             } else {
                 matches.put(includedDir, new BuildJob(includedDir));
             }
         }
 
         return new ArrayList<>(matches.values());
     }
 
     /**
      * Relativizes the project paths of the specified build jobs against the directory specified by
      * {@link #projectsDirectory} (if possible). If a project path does not denote a sub path of the projects directory,
      * it is returned as is.
      *
      * @param buildJobs The build jobs whose project paths should be relativized, must not be <code>null</code> nor
      *            contain <code>null</code> elements.
      * @throws java.io.IOException If any path could not be relativized.
      */
     private void relativizeProjectPaths(List<BuildJob> buildJobs) throws IOException {
         String projectsDirPath = projectsDirectory.getCanonicalPath();
 
         for (BuildJob buildJob : buildJobs) {
             String projectPath = buildJob.getProject();
 
             File file = new File(projectPath);
 
             if (!file.isAbsolute()) {
                 file = new File(projectsDirectory, projectPath);
             }
 
             String relativizedPath = relativizePath(file, projectsDirPath);
 
             if (relativizedPath == null) {
                 relativizedPath = projectPath;
             }
 
             buildJob.setProject(relativizedPath);
         }
     }
 
     /**
      * Relativizes the specified path against the given base directory. Besides relativization, the returned path will
      * also be normalized, e.g. directory references like ".." will be removed.
      *
      * @param path The path to relativize, must not be <code>null</code>.
      * @param basedir The (canonical path of the) base directory to relativize against, must not be <code>null</code>.
      * @return The relative path in normal form or <code>null</code> if the input path does not denote a sub path of the
      *         base directory.
      * @throws java.io.IOException If the path could not be relativized.
      */
     private String relativizePath(File path, String basedir) throws IOException {
         String relativizedPath = path.getCanonicalPath();
 
         if (relativizedPath.startsWith(basedir)) {
             relativizedPath = relativizedPath.substring(basedir.length());
             if (relativizedPath.startsWith(File.separator)) {
                 relativizedPath = relativizedPath.substring(File.separator.length());
             }
 
             return relativizedPath;
         } else {
             return null;
         }
     }
 
     /**
      * Returns the map-based value source used to interpolate POMs and other stuff.
      *
      * @param escapeXml {@code true}, to escape any XML special characters in the property values; {@code false}, to not
      * escape any property values.
      *
      * @return The map-based value source for interpolation, never <code>null</code>.
      */
     private Map<String, Object> getInterpolationValueSource(final boolean escapeXml) {
         Map<String, Object> props = new HashMap<>();
 
         if (filterProperties != null) {
             props.putAll(filterProperties);
         }
         props.put("basedir", this.project.getBasedir().getAbsolutePath());
         props.put("baseurl", toUrl(this.project.getBasedir().getAbsolutePath()));
         if (settings.getLocalRepository() != null) {
             props.put("localRepository", settings.getLocalRepository());
             props.put("localRepositoryUrl", toUrl(settings.getLocalRepository()));
         }
 
         return new CompositeMap(this.project, props, escapeXml);
     }
 
     /**
      * Converts the specified filesystem path to a URL. The resulting URL has no trailing slash regardless whether the
      * path denotes a file or a directory.
      *
      * @param filename The filesystem path to convert, must not be <code>null</code>.
      * @return The <code>file:</code> URL for the specified path, never <code>null</code>.
      */
     private static String toUrl(String filename) {
         /*
          * NOTE: Maven fails to properly handle percent-encoded "file:" URLs (WAGON-111) so don't use File.toURI() here
          * as-is but use the decoded path component in the URL.
          */
         String url = "file://" + new File(filename).toURI().getPath();
         if (url.endsWith("/")) {
             url = url.substring(0, url.length() - 1);
         }
         return url;
     }
 
     /**
      * Interpolates the specified POM/settings file to a temporary file. The destination file may be same as the input
      * file, i.e. interpolation can be performed in-place.
      * <p>
      * <b>Note:</b>This methods expects the file to be a XML file and applies special XML escaping during interpolation.
      * </p>
      *
      * @param originalFile The XML file to interpolate, must not be <code>null</code>.
      * @param interpolatedFile The target file to write the interpolated contents of the original file to, must not be
      * <code>null</code>.
      *
      * @throws org.apache.maven.plugin.MojoExecutionException If the target file could not be created.
      */
     void buildInterpolatedFile(File originalFile, File interpolatedFile) throws MojoExecutionException {
         getLog().debug("Interpolate " + originalFile.getPath() + " to " + interpolatedFile.getPath());
 
         try {
             String xml;
 
             Map<String, Object> composite = getInterpolationValueSource(true);
 
             // interpolation with token @...@
             try (Reader reader =
                     new InterpolationFilterReader(new XmlStreamReader(originalFile), composite, "@", "@")) {
                 xml = IOUtil.toString(reader);
             }
 
             try (Writer writer = new XmlStreamWriter(interpolatedFile)) {
                 interpolatedFile.getParentFile().mkdirs();
                 writer.write(xml);
             }
         } catch (IOException e) {
             throw new MojoExecutionException("Failed to interpolate file " + originalFile.getPath(), e);
         }
     }
 
     /**
      * Gets the (interpolated) invoker properties for an integration test.
      *
      * @param projectDirectory The base directory of the IT project, must not be <code>null</code>.
      * @return The invoker properties, may be empty but never <code>null</code>.
      * @throws org.apache.maven.plugin.MojoExecutionException If an I/O error occurred during reading the properties.
      */
     private InvokerProperties getInvokerProperties(final File projectDirectory, Properties globalInvokerProperties)
             throws MojoExecutionException {
         Properties props;
         if (globalInvokerProperties != null) {
             props = new Properties(globalInvokerProperties);
         } else {
             props = new Properties();
         }
 
         File propertiesFile = new File(projectDirectory, invokerPropertiesFile);
         if (propertiesFile.isFile()) {
             try (InputStream in = new FileInputStream(propertiesFile)) {
                 props.load(in);
             } catch (IOException e) {
                 throw new MojoExecutionException("Failed to read invoker properties: " + propertiesFile, e);
             }
         }
 
         Interpolator interpolator = new RegexBasedInterpolator();
         interpolator.addValueSource(new MapBasedValueSource(getInterpolationValueSource(false)));
         // CHECKSTYLE_OFF: LineLength
         for (String key : props.stringPropertyNames()) {
             String value = props.getProperty(key);
             try {
                 value = interpolator.interpolate(value, "");
             } catch (InterpolationException e) {
                 throw new MojoExecutionException("Failed to interpolate invoker properties: " + propertiesFile, e);
             }
             props.setProperty(key, value);
         }
 
         InvokerProperties invokerProperties = new InvokerProperties(props);
 
         // set default value for Invoker - it will be used if not present in properties
         invokerProperties.setDefaultDebug(debug);
         invokerProperties.setDefaultQuiet(quiet);
         invokerProperties.setDefaultGoals(goals);
         invokerProperties.setDefaultProfiles(profiles);
         invokerProperties.setDefaultMavenExecutable(mavenExecutable);
         invokerProperties.setDefaultMavenOpts(interpolatorUtils.interpolateAtPattern(mavenOpts));
         invokerProperties.setDefaultTimeoutInSeconds(timeoutInSeconds);
         invokerProperties.setDefaultEnvironmentVariables(environmentVariables);
         invokerProperties.setDefaultUpdateSnapshots(updateSnapshots);
         invokerProperties.setDefaultUserPropertiesFiles(testPropertiesFile);
 
         return invokerProperties;
     }
 
     static class ToolchainPrivateManager {
         private final ToolchainManager manager;
         private final MavenSession session;
 
         ToolchainPrivateManager(ToolchainManager manager, MavenSession session) {
             this.manager = manager;
             this.session = session;
         }
 
         boolean isToolchains(String type, Map<String, String> requirements) {
             return !manager.getToolchains(session, type, requirements).isEmpty();
         }
     }
 }