Tl;dr: my fault, nothing to see here. Since the newer build containers don't start, supervisord.log isn't created/appended to. I have noticed that the container command to start appears to have changed between the versions that spin up fine and the newer versions. On the working versions, the container startup command appears to be: /usr/bin/dumb-init -- /bin/bash /usr/local/bin/init.sh On the non-working, newer versions, it's: /usr/bin/dumb-init -- /bin/bash init.sh It dawned on me that is may be an issue with the path priority, and sure enough it was. I had a path statement in the compose files (which has been there for years) that overrode the built in one that you defined and since the new start doesn’t specifically include a full path for init.sh, it couldn’t find it (or the right version of it) and prevented the newer build containers from starting, I eliminated the path statement in my compose file and they are all back to full working order on the latest builds. Thank you for your response as it led me to the issue.