If "DOCKER_HOST" is set, we can usually assume the user is connecting to a remote Docker and thus not bind mount anything by default (meaning the Makefile will more often DWIM for our users). Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon) Upstream-commit: c2653b0a9ed4b371342fc2019c56d9433197171e Component: engine