When running `sudo make packages` on a FreeBSD 13.1 system, the package `FreeBSD-liby-dev` is built incorrectly. The package is tagged as a development package (as seen in the name, though I have not been able to figure out where, possibly in bsd.lib.mk), and `release/packages/generate-ucl.sh` automatically adds a dependency for every development package on it's companion non-development packages. There is no non-development package for liby, resulting in broken dependencies for `FreeBSD-liby-dev-13,1.pkg`.
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=266923
Just run into this-- appears it will be fixed in 13.2. Sorry. *** This bug has been marked as a duplicate of bug 266923 ***