dima

^TL;DR The contents of directories mounted with --mount=type=cache are not stored in the docker image, so it makes sense to cache intermediate directories, rather than target ones.

In dockerfile:1.3 there is a feature of mounting file system directories during the build process, that can be used for caching downloaded packages or compilation artifacts.

For example, the uwsgi package must be compiled every time it is installed, and at first glance, build times can be reduced by making the entire Python package directory cacheable: