isabelle-devel package failed to fetch

[aixer77@…]

It failed with the following error message.

$ sudo port install isabelle-devel
--->  Computing dependencies for isabelle-devel
--->  Fetching isabelle-devel
--->  Attempting to fetch Isabelle_01-Oct-2009.tar.gz from http://ykf.ca.distfiles.macports.org/MacPorts/mpdistfiles/isabelle-devel
--->  Attempting to fetch Isabelle_01-Oct-2009.tar.gz from http://distfiles.macports.org/isabelle-devel
--->  Attempting to fetch Isabelle_01-Oct-2009.tar.gz from http://lil.fr.distfiles.macports.org/isabelle-devel
--->  Attempting to fetch Isabelle_01-Oct-2009.tar.gz from http://isabelle.in.tum.de//devel/
--->  Attempting to fetch Isabelle_01-Oct-2009.tar.gz from http://aarnet.au.distfiles.macports.org/pub/macports/mpdistfiles/isabelle-devel
--->  Attempting to fetch Isabelle_01-Oct-2009.tar.gz from http://sea.us.distfiles.macports.org/macports/mpdistfiles/isabelle-devel
--->  Attempting to fetch Isabelle_01-Oct-2009.tar.gz from http://svn.macports.org/repository/macports/distfiles/isabelle-devel
Error: Target org.macports.fetch returned: fetch failed
Log for isabelle-devel is at: /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_release_ports_math_isabelle-devel/main.log
Error: Status 1 encountered during processing.
To report a bug, see <http://guide.macports.org/#project.tickets>