LOGGER.warn("artifact '{}' already attached, replacing previous instance", artifact);
            attachedArtifacts.set(index, artifact);
        } else {
            attachedArtifacts.add(artifact);
        }
    }

    /**
     * Returns a read-only list of the attached artifacts to this project.
     *
     * @return the attached artifacts of this project
     */

        return lifecycles.computeIfAbsent(project.getId(), k -> new ArrayDeque<>());
    }

    /**
     * Copy packaged and attached artifacts from this project to the
     * project local repository.
     * This allows a subsequent build to resume while still being able
     * to locate attached artifacts.
     *
     * @param project the project to copy artifacts from
     */

2.0-rc2-SNAPSHOT maven-compiler-plugin 2.0-beta-2-SNAPSHOT maven-deploy-plugin 2.0-beta-1 true true maven-install-plugin 2.0-beta-2-SNAPSHOT maven-jar-plugin 2.0-rc2-SNAPSHOT maven-javadoc-plugin 2.0-beta-2-SNAPSHOT attach-javadocs jar true maven-resources-plugin 2.0-beta-2 maven-source-plugin 2.0-rc1 attach-sources jar true maven-surefire-plugin 2.0-beta-2-SNAPSHOT false snapshots Maven Central Development Repository http://snapshots.maven.codehaus.org/maven2 false central Maven Repository Switchboard http:...

          <description>
            <![CDATA[
            The classifier of the dependency. It is appended to
            the filename after the version. This allows:
            <ul>
            <li>referring to attached artifact, for example {@code sources} and {@code javadoc}:
            see <a href="../maven-core/artifact-handlers.html">default artifact handlers</a> for a list,</li>
            <li>distinguishing two artifacts

 * under the License.
 */
package org.apache.maven.project;

import org.apache.maven.artifact.Artifact;

/**
 * This exception is thrown if an application attempts to attach
 * two of the same artifacts to a single project.
 *
 * TODO Make this a checked exception, and modify the API of MavenProjectHelper.
 * Currently, this modification would create compatibility problems for existing plugins.

            File systemFile = artifact.getFile();

            if (systemFile == null) {
                throw new ArtifactNotFoundException("System artifact: " + artifact + " has no file attached", artifact);
            }

            if (!systemFile.exists()) {
                throw new ArtifactNotFoundException(

        InternalMavenSession session = ((DefaultProject) project).getSession();
        Collection<Artifact> attached = map(
                getMavenProject(project).getAttachedArtifacts(),
                a -> session.getArtifact(RepositoryUtils.toArtifact(a)));
        return Collections.unmodifiableCollection(attached);
    }

    @Override
    public Collection<Artifact> getAllArtifacts(Project project) {

                <phase>package</phase>
                <configuration>
                  <finalName>./</finalName>
                  <appendAssemblyId>false</appendAssemblyId>
                  <attach>false</attach>
                  <outputDirectory>${distributionTargetDir}</outputDirectory>
                  <descriptors>
                    <descriptor>src/assembly/dir.xml</descriptor>
                  </descriptors>

                    <plugin>
                        <artifactId>maven-source-plugin</artifactId>
                        <executions>
                            <execution>
                                <id>attach-sources</id>
                                <phase>prepare-package</phase>
                                <goals>
                                    <goal>jar-no-fork</goal>
                                </goals>

    Optional<Path> getPath(Project project);

    /**
     * Returns an immutable collection of attached artifacts for given project.
     */
    @Nonnull
    Collection<Artifact> getAttachedArtifacts(Project project);

    /**
     * Returns project's all artifacts as immutable collection. The list contains all artifacts, even the attached ones,