Thanks for reporting the problem. This appears to be a bug in macOS awk, as it is reporting a syntax error here: stdoff_column = 2 * /^Zone/ + 1 even though POSIX says this is a valid awk statement. I don't observe the bug on FreeBSD 13.0, where "awk --version" reports "awk version 20190529 (FreeBSD)". Please try the attached patch, which I have installed in the development repository. I hope it works around the macOS bug, but I don't have easy access to macOS to try it. If this patch works for you, please file a bug report with whoever is maintaining 'awk' on macOS, as statements like the above should work. If I'm right about the bug, then to build without the patch you can install a working 'awk' on your system (e.g., FreeBSD or GNU 'awk'), or run 'make traditional_tarballs' on a working platform (e.g., FreeBSD or GNU/Linux) and then transport the resulting tarball to macOS.