scp:// urls not recognised, even when wagon-ssh is installed.

I have got the <install> task working to pull in the various deployment wagons

<target name="m2-wagons" depends="m2-pom,ssh-init">
<m2:install-provider artifactId="wagon-ssh"
version="$

"/>
<m2:install-provider artifactId="wagon-ssh-external"
version="$

"/>
<m2:install-provider artifactId="wagon-file"
version="$

"/>
<m2:install-provider artifactId="wagon-ftp"
version="$

"/>
</target>

But when I run a deploy target and use the scp:// protocol , I get the unknown protocol error.

<target name="m2-ssh-deploy" depends="m2-pom,ssh-init,m2-wagons">

<property name="m2.upload.url"
value="scp://$

/www/repository"/>
<m2:deploy file="$

">
<remoteRepository url="$

">
<authentication username="$

"
privateKey="$

"/>
</remoteRepository>
<pom refid="m2.pom"/>
</m2:deploy>
</target>

This is only for scp:, the others, scpexe, file: and ftp: do work. Is the url schema wrong? Is there any way to enum what protocols are currently supported?

I would recommend that the error message "unsupported protocol" is supplemented with a listing of what protocols are supported. That way its easier to differentiate spelling error from uninstalled wagon.