I use Buddy for CI/CD and utilize a Docker image for a build environment. The Docker I used for Sage 9 doesn’t work for Sage 10 so I decided to make my own. I hope this helps other developers in similar situations!
Most of the Dockerfiles I saw for Sage 9 appeared too complicated for my purposes so I started with Alpine and added the bare requirements for Sage 10 including PHP7 (with mbstring , phar, json, openssl, fileinfo), node, composer, and yarn. I’ve only tested for Sage 10.0.0-beta.1 right now.
If you catch composer errors I found out quickly you’re probably missing PHP packages.