jenkinsci/git-plugin — pull request #81 by jsenko (2012-08-09 10:53:43+00:00)
Title: Add option to use shallow clone to save disk space when you just want to access the latest version of a repository.

Cloning git repositories can cause high load on git server as well as on network. If would be nice to have an option in git plugin to perform only shallow clone. It could significantly reduce amount of transfered data.

This is the original issue
http://issues.jboss.org/browse/JBQA-6663