Error starting dev server using docker

Need a bit more info here. At least what branch you are using.

Edit: I suspect you are using master branch. I'm guessing 0.18.x or 0.19.x is more relevant.

Another reason for this happening is that you have an old python:3 docker image. Try adding --pull parameter the build command to override local cache. This is related to this commit in master.

I've did complete system purge on my Docker recently and can confirm that libopenjpeg-dev is gone. Cherry-picking the new lib from linked commit fixed it for me. ;)

Looks like this is related to python images now using debian 9. I guess it's always a good idea to use the --pull parameter when building the compose setup to ensure no stale base images are used.

I guess in ./dev init script we should do docker-compose build --pull --force-rm to catch those sooner?

Probably not a bad idea. Then docker will check if there are new images available for the image tag. The same python:3.6 image will normally be built more than once because its base images also change. For example when the debian image gets a security fix.