VanillaOS is a fixed-release distribution based on Ubuntu and is an immutable operating system. The core parts of the system are locked down to prevent unwanted changes and corruption from third-party applications or a faulty update.
curl https://updates.safing.io/latest/linux_amd64/packages/portmaster-installer.deb --output /tmp/portmaster-installer.deb
abroot exec alernatively use abroot shellsudo abroot exec apt install /tmp/portmaster-installer.deb
cd /etc/systemd/system/
sudo rm portmaster.service
sudo ln -s /.system/opt/safing/portmaster/portmaster.service
Quick copy paste:
curl https://updates.safing.io/latest/linux_amd64/packages/portmaster-installer.deb --output /tmp/portmaster-installer.deb
sudo abroot exec apt install /tmp/portmaster-installer.deb
reboot
cd /etc/systemd/system/
sudo rm portmaster.service
sudo ln -s /.system/opt/safing/portmaster/portmaster.service
reboot
After installing Portmaster you have to manually remove and re-symlink the service to /.system/opt/safing/portmaster/portmaster.service