ast conflicts with libast

[barracuda156]

Error: Failed to activate libast: Image error: /opt/local/lib/libast.a is being used by the active ast port.  Please deactivate this port first, or use 'port -f activate libast' to force the activation.
    while executing
"throw registry::image-error $msg"
    ("foreach" body line 49)
    invoked from within
"foreach file $imagefiles {
                incr progress_step
                _progress update $progress_step $progress_total_steps
                se..."
    invoked from within
"registry::write {
            # extract phase complete, assume 1/3 is done
            set progress_step $num_imagefiles
            foreach file $ima..."
Error: See /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_libast/libast/main.log for details.
Error: Follow https://guide.macports.org/#project.tickets if you believe there
is a bug.