Run as docker 3 ways:
- explicitly run a derivation with docker as the system
- pass a derivation (or many) into a docker image build builtin
- pass the --system=docker command line argument
For local build:
- mount the build with ~/bramble/store at a fixed path
- don't run as root
- build somewhere outside of the store but with the same path length?
- copy the result out of the container? oh, no, could just write it to another volume
- yeah, build somewhere that's not the store