This repository aims to provide (possibly daily) builds of Docker containers based on the then-current state of the R-devel SVN repository.
It is part of the Rocker project.
Excellent question, but the answer will get nerdy quickly. Docker containers
are composed of layers implemented via AUFS.
Each RUN command is one layer. This makes it impossible to reclaim
filespace from an earlier layer in a later layer -- so the R-devel container
can not easily remove (temp.) files and directories.
For drd we went the other route: The container is built in a single
invocation of RUN which permits us to reclaim space for an overall smaller
container. But it is sort-of running against the grain of how Docker
containers are built, and hence still somewhat experimental.
But if you just want a smaller container with a current R-devel build, this may be the one.