Never mind - answered my own question:

<project name="Basic Tiles Build" default="dist">
    <property environment="env" />
    <property name="output.dir" value="../../catalogs/Tiles" />

    <!--
        Sets the "mosaic.sdk.dir" using this precedence:
    1. MOSAIC_HOME system environment variable
    2. Relative path that is the grandparent of this script's directory
    -->
    <condition property="mosaic.sdk.dir" value="${env.MOSAIC_HOME}/sdk">
        <isset property="env.MOSAIC_HOME" />
    </condition>
    <condition property="mosaic.sdk.dir" value="${root.dir}/sdk">
        <available file="${root.dir}/sdk" type="dir" />
    </condition>
    <condition property="mosaic.sdk.dir" value="${basedir}/../../../../sdk">
        <available file="${basedir}/../../../../sdk" type="dir" />
    </condition>

    <condition property="mosaic.sdk.dir.found">
        <isset property="mosaic.sdk.dir" />
    </condition>
    <fail message="Failed to find Mosaic SDK" unless="mosaic.sdk.dir.found" />
    <echo message="Mosaic SDK ${mosaic.sdk.dir}" />

    <property name="FLEX_HOME" value="${env.FLEX_HOME}" />
    <taskdef resource="flexTasks.tasks" classpath="${FLEX_HOME}/ant/lib/flexTasks.jar" />

    <!-- =================================================================== -->
    <!-- Clean                                                               -->
    <!-- =================================================================== -->
    <target name="clean">
        <delete dir="bin-debug" />
    </target>

    <!-- =================================================================== -->
    <!-- Build                                                               -->
    <!-- =================================================================== -->
    <target name="build">
        <antcall target="-build">
            <param name="file.name" value="ComplexContextSetGet" />
        </antcall>
        <antcall target="-build">
            <param name="file.name" value="ComplexContextWatcher" />
        </antcall>
        <antcall target="-build">
            <param name="file.name" value="ContextWatcher" />
        </antcall>
        <antcall target="-build">
            <param name="file.name" value="MessageReceiver" />
        </antcall>
        <antcall target="-build">
            <param name="file.name" value="MessageSender" />
        </antcall>
        <antcall target="-build">
            <param name="file.name" value="SetAndGetContext" />
        </antcall>
        <antcall target="-build">
            <param name="file.name" value="RetrieveData" />
        </antcall>
    </target>
    <target name="-build">
        <antcall target="compile">
            <param name="target.dir" value="bin-debug" />
            <param name="debug" value="true" />
            <param name="file.name" value="${file.name}" />
        </antcall>

        <mkdir dir="${output.dir}/${file.name}" />
        <copy file="bin-debug/${file.name}.swf" todir="${output.dir}/${file.name}" />

    </target>

    <target name="compile">
        <mkdir dir="${target.dir}" />
        <mxmlc file="src/${file.name}.mxml"
               output="${target.dir}/${file.name}.swf"
               debug="${debug}"
               actionscript-file-encoding="UTF-8"
               keep-generated-actionscript="true"
               static-rsls="true"
               fork="true"
               maxmemory="512m">
            <load-config filename="${FLEX_HOME}/frameworks/flex-config.xml" />
            <source-path path-element="src/" />
            <compiler.include-libraries dir="${mosaic.sdk.dir}/flex/sdks/4.1.0/frameworks/libs" append="true">
                <include name="mosaic-tile.swc" />
            </compiler.include-libraries>
           <includes symbol="mx.managers.systemClasses.MarshallingSupport" />
            <include-libraries file="${FLEX_HOME}/frameworks/libs/automation/automation.swc" />
            <include-libraries file="${FLEX_HOME}/frameworks/libs/automation/automation_agent.swc" />
            <include-libraries file="${FLEX_HOME}/frameworks/libs/automation/qtp.swc" />
            <include-libraries file="${FLEX_HOME}/frameworks/libs/automation/automation_dmv.swc" />
            <source-path path-element="${FLEX_HOME}/frameworks" />
        </mxmlc>
    </target>

    <!-- =================================================================== -->
    <!-- Dist                                                                -->
    <!-- =================================================================== -->
    <target name="dist" depends="clean,build" />
    <target name="smoke" depends="build" />
    <target name="all" depends="build" />
</project>