Bug in LilyPond

[Siegfried]

I'm trying to install LilyPond but I keep getting this error:

Mac:Cesar:Desktop$ sudo port install lilypondError: Unable to execute port: couldn't open "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_ports_textproc_lilypond/lilypond/work/.macports.lilypond.state": permission denied
To report a bug, see <http://guide.macports.org/#project.tickets>

Any clues?