variables not interpolated while reading settings.xml

I suspect that variables are not interpolated while reading settings.xml.

For instance, I have set the environment variable REPO_DIR=c:/.m2repo. However, my <localRepository> setting is not respected if i use a ${env.variable} for the localRepository. I also tried adding -DREPO_DIR=c:/.m2repo to ANT_OPTS and using ${variable}, but still no luck.

I was only able to test this in ~/.m2/settings.xml , and ~/.ant/settings.xml, because of MANTTASKS-92

<settings>
    <!-- OK  -->
    <localRepository>c:/.m2repo</localRepository>
    <!-- NOT ok  -->
    <!--localRepository>${env.REPO_DIR}</localRepository-->
    <!-- NOT ok  -->
    <!--localRepository>${REPO_DIR}</localRepository-->
</settings>