I tried another upgrade and it looks like at some point a new “yarn install” section was added to web.template.yml which breaks inside the isolated environment.
- exec:
cd: $home
cmd:
- "[ ! -d 'node_modules' ] || su discourse -c 'yarn install --production && yarn cache list'"
When comparing the contents of the old and new container it looks like there’s a bunch of cached yarn packages on the new one in /usr/local/share/.cache/yarn/v6 but nothing in the old one, I guess all the required node.js used to be included in the base image but now they get updated during a rebuild?
I will experiment with copying out the yarn cache the same way as the ruby cache and see if i can get yarn to use the cached packages from the build box.