echoping +gnutls fails to build on BigSur 11.3.1

[pwosel]

pwo@mucsxa02 apache % sudo port clean echoping  
--->  Cleaning echoping
pwo@mucsxa02 apache % sudo port install echoping  +gnutls
--->  Computing dependencies for echoping
--->  Fetching archive for echoping
--->  Attempting to fetch echoping-6.0.2_5+gnutls.darwin_20.x86_64.tbz2 from https://fra.de.packages.macports.org/echoping
--->  Attempting to fetch echoping-6.0.2_5+gnutls.darwin_20.x86_64.tbz2 from https://packages.macports.org/echoping
--->  Attempting to fetch echoping-6.0.2_5+gnutls.darwin_20.x86_64.tbz2 from https://nue.de.packages.macports.org/echoping
--->  Fetching distfiles for echoping
--->  Verifying checksums for echoping
--->  Extracting echoping
--->  Applying patches to echoping
--->  Configuring echoping
--->  Building echoping
Error: Failed to build echoping: command execution failed
Error: See /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_net_echoping/echoping/main.log for details.
Error: Follow https://guide.macports.org/#project.tickets to report a bug.
Error: Processing of port echoping failed

pwo@mucsxa02 apache % less /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_net_echoping/echoping/main.log
...
...
:info:build  /usr/bin/clang -DHAVE_CONFIG_H -I. -I/opt/local/include -isysroot/Library/Developer/CommandLineTools/SDKs/MacOSX11.3.sdk -pipe -Os -DLDAP_DEPRECATED -isysroot/Library/Developer/CommandLineTools/SDKs/MacOSX11.3.sdk -arch x86_64 -MT dns.lo -MD -MP -MF .deps/dns.Tpo -c dns.c -o dns.o >/dev/null 2>&1
:info:build mv -f .deps/dns.Tpo .deps/dns.Plo
:info:build /bin/sh ./libtool --tag=CC   --mode=link /usr/bin/clang  -pipe -Os -DLDAP_DEPRECATED -isysroot/Library/Developer/CommandLineTools/SDKs/MacOSX11.3.sdk -arch x86_64 -module -L/opt/local/lib -Wl,-headerpad_max_install_names -Wl,-syslibroot,/Library/Developer/CommandLineTools/SDKs/MacOSX11.3.sdk -arch x86_64 -o dns.la -rpath /opt/local/lib/echoping dns.lo  -lpopt  -lresolv
:info:build /usr/bin/clang  -o .libs/dns.0.0.0.so -bundle  .libs/dns.o  -L/opt/local/lib -lpopt -lresolv -arch x86_64 -Wl,-headerpad_max_install_names -Wl,-syslibroot -Wl,/Library/Developer/CommandLineTools/SDKs/MacOSX11.3.sdk -arch x86_64
:info:build Undefined symbols for architecture x86_64:
:info:build   "_err_quit", referenced from:
:info:build       _start in dns.o
:info:build   "_err_ret", referenced from:
:info:build       _nsError in dns.o
:info:build   "_err_sys", referenced from:
:info:build       _start in dns.o
:info:build   "_to_upper", referenced from:
:info:build       _nsError in dns.o
:info:build       _init in dns.o
:info:build ld: symbol(s) not found for architecture x86_64
:info:build clang: error: linker command failed with exit code 1 (use -v to see invocation)
:info:build make[4]: *** [dns.la] Error 1
:info:build make[4]: Leaving directory `/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_net_echoping/echoping/work/echoping-6.0.2/plugins/dns'
:info:build make[3]: *** [all] Error 2
:info:build make[3]: Leaving directory `/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_net_echoping/echoping/work/echoping-6.0.2/plugins/dns'
:info:build make[2]: *** [all-recursive] Error 1
:info:build make[2]: Leaving directory `/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_net_echoping/echoping/work/echoping-6.0.2/plugins'
:info:build make[1]: *** [all-recursive] Error 1
:info:build make[1]: Leaving directory `/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_net_echoping/echoping/work/echoping-6.0.2'
:info:build make: *** [all] Error 2
:info:build make: Leaving directory `/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_net_echoping/echoping/work/echoping-6.0.2'
:info:build Command failed:  cd "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_net_echoping/echoping/work/echoping-6.0.2" && /usr/bin/make -j12 -w all 
:info:build Exit code: 2
:error:build Failed to build echoping: command execution failed
:debug:build Error code: CHILDSTATUS 99144 2
:debug:build Backtrace: command execution failed
:debug:build     while executing
:debug:build "system {*}$notty {*}$nice $fullcmdstring"
:debug:build     invoked from within
:debug:build "command_exec build"
:debug:build     (procedure "portbuild::build_main" line 8)
:debug:build     invoked from within
:debug:build "$procedure $targetname"
:error:build See /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_net_echoping/echoping/main.log for details.