gnuradio @3.77.11: validity error : Could not load the external subset "docbookx.dtd"

[stephensworld]

I would like to build gnuradio, but it fails after some minutes.

Thanks
Stephan

--->  Cleaning fop
--->  Fetching archive for getopt
--->  Attempting to fetch getopt-1.1.6_0.darwin_16.x86_64.tbz2 from https://packages.macports.org/getopt
--->  Attempting to fetch getopt-1.1.6_0.darwin_16.x86_64.tbz2.rmd160 from https://packages.macports.org/getopt
--->  Installing getopt @1.1.6_0
--->  Activating getopt @1.1.6_0
--->  Cleaning getopt
--->  Fetching archive for xmlto
--->  Attempting to fetch xmlto-0.0.28_0.darwin_16.x86_64.tbz2 from https://packages.macports.org/xmlto
--->  Attempting to fetch xmlto-0.0.28_0.darwin_16.x86_64.tbz2.rmd160 from https://packages.macports.org/xmlto
--->  Installing xmlto @0.0.28_0
--->  Activating xmlto @0.0.28_0
--->  Cleaning xmlto
--->  Fetching archive for gnuradio
--->  Attempting to fetch gnuradio-3.7.11_3+docs+grc+jack+portaudio+qtgui+sdl+swig+uhd+wavelet+wxgui.darwin_16.x86_64.tbz2 from https://packages.macports.org/gnuradio
--->  Attempting to fetch gnuradio-3.7.11_3+docs+grc+jack+portaudio+qtgui+sdl+swig+uhd+wavelet+wxgui.darwin_16.x86_64.tbz2 from http://fco.it.packages.macports.org/mirrors/macports-packages/gnuradio
--->  Attempting to fetch gnuradio-3.7.11_3+docs+grc+jack+portaudio+qtgui+sdl+swig+uhd+wavelet+wxgui.darwin_16.x86_64.tbz2 from http://her.gr.packages.macports.org/gnuradio
--->  Fetching distfiles for gnuradio
--->  Verifying checksums for gnuradio
--->  Extracting gnuradio
--->  Applying patches to gnuradio
--->  Configuring gnuradio
--->  Building gnuradio
Error: Failed to build gnuradio: command execution failed
Error: See /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_release_tarballs_ports_science_gnuradio/gnuradio/main.log for details.
Error: Follow https://guide.macports.org/#project.tickets to report a bug.
Error: Processing of port gnuradio failed
sh-3.2#