解法在這裡
https://tinkerboarding.co.uk/forum/thread-1735-page-2.html
wget https://snapshot.debian.org/archive/debian-security/20180701T015633Z/pool/updates/main/c/chromium-browser/chromium_67.0.3396.87-1~deb9u1_armhf.deb
sudo dpkg -i chromium_67.0.3396.87-1~deb9u1_armhf.deb
sudo apt-mark hold chromium