# pkg install git gettext-tools# cd /usr# rm -rf src ports# git clone https://github.com/opnsense/ports# git clone https://github.com/opnsense/core
# cd /usr/ports# git checkout 16.1.8
# portmaster -a
# cd /usr/core# git checkout 16.1.8# make package# pkg add -f opnsense-16.1.8.txz
# opensense-update -bkr 16.1.8
Small correction: installation should be "pkg add -f 16.1.1/All/opnsense-16.1.1.txz"