How can I deploy a zip file created with the maven-antrun-plugin?

I'm using the maven-antrun-plugin to do a bunch of work with Ant, which ultimately results in a zip file. I'd like to deploy the zip file to our maven server (Artifactory). The maven-antrun-portion works as intended and successfully creates the zip file; however deployment fails with the following error message:

org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.apache.maven.plugins:maven-deploy-plugin:2.6:deploy (default-deploy) on project projectname: The packaging for this project did not assign a file to the build artifact

My POM file is as follows:

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.company.division</groupId>
    <artifactId>projectname</artifactId>
    <version>1.0.0-SNAPSHOT</version>
    <packaging>pom</packaging>

    <parent>
        <groupId>com.company.product</groupId>
        <artifactId>parentproject</artifactId>
        <version>1.0.0</version>
    </parent>

    <distributionManagement>
        <snapshotRepository>
            <id>artifactory</id>
            <name>artifactory-snapshots</name>
            <url>http://localartifactoryserver/artifactory/libs-snapshot-local</url>
            <uniqueVersion>false</uniqueVersion>
        </snapshotRepository>
    </distributionManagement>

    <dependencies>
        <!-- Some dependencies... -->
    </dependencies>

    <build>
        <plugins>
            <!-- Compiler plugin -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>2.3.2</version>
                <configuration>
                    <source>1.6</source>
                    <target>1.6</target>
                    <encoding>UTF8</encoding>
                    <optimize>true</optimize>
                </configuration>
            </plugin>

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-antrun-plugin</artifactId>
                <version>1.6</version>
                <executions>
                    <execution>
                        <id>compile</id>
                        <phase>compile</phase>
                        <configuration>
                            <target>
                                <!-- Do lots of other stuff with Ant. -->

                                <!-- Create a zip file. -->
                                <zip basedir="mydir" destfile="${WORKSPACE}/MyZip.zip" />
                            </target>
                        </configuration>
                        <goals>
                            <goal>run</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-deploy-plugin</artifactId>
                <version>2.6</version>
                <configuration>
                    <groupId>${project.groupId}</groupId>
                    <artifactId>${project.artifactId}</artifactId>
                    <version>${project.version}</version>
                    <packaging>zip</packaging>
                    <file>MyZip.zip</file>
                    <url>${project.distributionManagement.snapshotRepository.url}</url>
                </configuration>
              </plugin>
        </plugins>
    </build>
</project>

When I invoke this (from the parent POM) with mvn -U -pl projectname clean deploy I get the aforementioned error during the deploy phase. Does anyone know what I'm doing wrong or how I can fix this?

The solution that worked for me (I'm not sure if it is ideal, it seems rather hackish) was to switch to the deploy:deploy-file goal:

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-deploy-plugin</artifactId>
    <version>2.6</version>
    <goals>
        <goal>deploy-file</goal>
    </goals>
    <configuration>
        <repositoryId>artifactory</repositoryId>
        <packaging>zip</packaging>
        <generatePom>true</generatePom>
        <url>${project.distributionManagement.snapshotRepository.url}</url>
        <artifactId>${project.artifactId}</artifactId>
        <groupId>${project.groupId}</groupId>
        <version>${project.version}</version>
        <file>${WORKSPACE}/MyZip.zip</file>
    </configuration>
</plugin>

and invoke it explicitly:

mvn -U -X -pl projectname clean install deploy:deploy-file