I've seen a number of examples, e.g. here, where people are including locale resource bundles by referencing the locale attribute in the element. For some reason this doesn't work for me. Here's what I have for the task:

<compc output="${deploy.dir}/myfrmwrk.swc" locale="en_US">
    <source-path path-element="${basedir}/src/main/flex"/>
    <include-sources dir="${basedir}/src/main/flex" includes="*" />
    <include-libraries file="${basedir}/libs"/>
    <compiler.external-library-path dir="${FLEX_HOME}/frameworks/libs/player/9" append="true">
        <include name="playerglobal.swc"/>
    </compiler.external-library-path>
    <compiler.library-path dir="${FLEX_HOME}/frameworks" append="true">
        <include name="libs"/>
        <include name="locale/${locale}"/>
    </compiler.library-path>
    <load-config filename="${basedir}/fb3config.xml" />
</compc>

This fails with a bunch of errors of the form:

[compc] Error: could not find source for resource bundle ...

I can make it build with this one change:

<include name="locale/en_US"/>

The configuration file generated by Flex Builder 3 actually renders this as "locale/{locale}" (notice the $ is missing). I've tried that as well with the same (failing) results.

For now, I'm doing OK directly injecting en_US as we won't be doing localization bundles for quite some time, but I will eventually need to get this working. Also, it bugs me that I can't make it work the way that it SHOULD work!