Hi! I tried updating both /usr/src and /usr/ports with OpenCVS. It worked, but it also downloaded empty directories (GNU CVS never did that):
$ ls /usr/src/ CVS Makefile.cross distrib games include kerberosV libexec regress share usr.bin Makefile bin etc gnu kerberosIV lib lkm sbin sys usr.sbin $ ls /usr/src/kerberosIV/man/ CVS $ ls /usr/ports/www/vimb/ CVS patches pkg $ My ~/.cvsrc is: # $OpenBSD: dot.cvsrc,v 1.3 2016/10/31 20:50:11 tb Exp $ # diff -uNp update -Pd checkout -P rdiff -u