/usr/bin/ld: error: NBCCommonData.o: invalid alignment of section headers
Sure enough NBCCommonData.o has misaligned section headers:
% readelf -S ./work/NXT/NBCCommonData.o
There are 8 section headers, starting at offset 0x2cf03:
The port can probably just have LLD_UNSAFE added to its Makefile, but fixing the root cause would be better.
A commit references this bug:
Date: Sun Jun 17 16:15:33 UTC 2018
New revision: 472610
lang/nbc: fix build with lld by setting LLD_UNSAFE 
While here, set the license (MPL11) and bump PORTREVISION
PR: 228613 
Submitted by: emaste 
There seems to be no magical fpc knob for setting the alignment, so use LLD_UNSAFE for now.