I can't believe so useful a feature has languished so long. Is there a technical obstacle, or is it just that no one in a position to make the change happened on it? We make huge use of reference repos and something like this would be very convenient - 5 minute git fetch vs seconds goes a long way.
If this feature is too big, maybe an alternative is to just expose more git features, even if they aren't pretty. For managing a reference repo, I need Jenkins integration for credentials and URL, but then execute (out of the workspace) similar to:
### Create the reference repo if it does not exist yet, then update
cd \$REFPATH
if [ ! -d "myRepo.git" ]; then git clone --mirror https:ls
cd "myRepo.git/"
git fetch --all --prune
Git has many, many features: if we don't have time for "nice" integration, a lot of us would take the quick and dirty approach to get more of those features
Good suggestion. Jesse Glick implemented something similar in the Mercurial plugin. The Mercurial plugin copies to a central location on the Jenkins server, then uses the Jenkins slave communication system to transfer the repository to slaves as needed.