Looks like there are two problems here.
Your main.log file contains several attempts to install this port. The one that started from a clean slate has this error:
Loop.cpp:4224:34: error: invalid operands to binary expression ('__bind<int &, sockaddr *&, unsigned int &>' and 'int')
4224 | if (bind(newFD, addr, addrlen) == -1)
| ~~~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~~
This a probably due to the new Xcode's pickier version of clang.
After that, you tried again without cleaning first, and it failed with:
Error: Failed to build nxcomp: error renaming "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_net_nxcomp/nxcomp/work/nx-libs-3.5.99.22/nxcomp/VERSION": no such file or directory
This is a mistake in how we worked around a previous problem in [84f6dc45a4d78fc612d817332668e396353975c4/macports-ports]. We rename the VERSION file to avoid a conflict with C++20 compilers, but it should happen before the build phase, not at the beginning of the build phase. The patch phase would be a good place to do that.
