Failed to build gnuplot: command execution failed

[AlPiFr]

I'm trying to upgrade outdated ports and it fails while upgrading Gnuplot.

##############################
---> Computing dependencies for gnuplot
---> Fetching archive for gnuplot
---> Attempting to fetch gnuplot-5.4.2_0+aquaterm+luaterm+pangocairo+wxwidgets+x11.darwin_19.x86_64.tbz2 from ​https://packages.macports.org/gnuplot
---> Attempting to fetch gnuplot-5.4.2_0+aquaterm+luaterm+pangocairo+wxwidgets+x11.darwin_19.x86_64.tbz2 from ​https://mse.uk.packages.macports.org/gnuplot
---> Attempting to fetch gnuplot-5.4.2_0+aquaterm+luaterm+pangocairo+wxwidgets+x11.darwin_19.x86_64.tbz2 from ​https://fra.de.packages.macports.org/gnuplot
---> Fetching distfiles for gnuplot
---> Verifying checksums for gnuplot
---> Extracting gnuplot
---> Applying patches to gnuplot
---> Configuring gnuplot
---> Building gnuplot
Error: Failed to build gnuplot: command execution failed
Error: See /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_release_tarballs_ports_math_gnuplot/gnuplot/main.log for details.
Error: Follow ​https://guide.macports.org/#project.tickets if you believe there is a bug.
Error: Processing of port gnuplot failed
##############################

I tried "port clean gnuplot" but it did not solve the problem. Does anybody have an idea ? Thanks

[AlPiFr]

/opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_release_tarballs_ports_math_gnuplot/gnuplot/main.log