In a parametrized build job the parameter is only visible from the build section
and not even before.

It would be nice, for example, if I could specify with the parameter passed by
the one who actually runs the job, which tag to check-out from the remote
repository, but at the moment this is not possible, due to the fact that the
parameter is not available from the CVS section which preceeds the build section.

The workaround to call a cvs update from a build bash script do the job, but it
is not very useful, because doing so, some of the nice features of the SCM
plugin bundled in Husdon, such as the changes report, are not available.