So many gotchas like this in dockerfiles. I think the issue stems from it being such a leaky abstraction. To use it correctly you need to know how docker works internally inside and out, as well as Linux inside and out.

The default choices are baffling in docker, it really is a worse-is-better kind of tool.

Has anyone worked on a replacement for dockerfiles? I know buildah is an alternative to docker build, but it just uses the same file format