Rasmus Villemoes <rv@xxxxxxxxxxxxxxxxxx> writes: > At $dayjob, most of our projects are organized as a rather small > superproject, with a number of git submodules. Usually, one of those > submodules is a linux kernel git tree. > > For CI testing, we create a fresh docker container which starts by doing > a "git clone --recursive $superproject", which takes quite a while due > to the linux repo. So we'd like to speed that up by having a reasonable > up-to-date linux repo on each build slave, mapping that into the docker > container, and then telling git "when you get to cloning the src/linux > submodule, look over here for objects", i.e. having some way to have > --reference-if-able and --disassociate in effect for submodules. > > If this is already possible, I can't find it in the documentation. And > if it doesn't exist, I can't really think of a good way to define the UI > for giving those options (other than, perhaps, having a top-level > --reference-if-able pass down to the submodules with the meaning 'when > initializing the submodule at some/path, try to use the submodule, if > any, at some/path in the referenced top-level repo'". Sorry for not giving a full solution but I suspect that discussing this topic will lead to a useful new feature, similar in spirit to the url rewriting (i.e. "url.$LOCAL.insteadOf = $REMOTE") to tell Git to use a local mirror $LOCAL instead of the remote authentic repository when interacting with $REMOTE. Perhaps "url.$LOCALREF.autoReference = $REMOTE" to specify a local mirror that does not have to be completely up-to-date, that will altomatically be used as if "--reference-if-able $LOCALREF" is passed when running "git clone $REMOTE", or something like that. The actual design has to get a lot more involved, including deciding: - if autoReference is orthogonal to --disssociate (I think it should be but others may differ). - how the way --dissociate is passed down from the top-level superproject to cloning of submodules is controlled (passing unconditionally would probably be too coarse, but I dunno). etc. etc.
