the only thing i hear about members of our team missing from svn are using externals. one of our members would create an external in his current client project

the only thing i hear about members of our team missing from svn are using externals. one of our members would create an external in his current client project to our open source repo. now while working on his client project, if he encountered a bug in our open source project, he could fix and test in the client project, but the change would get committed to our open source project. while git has submodules, they no way near have the flexibility of externals. if git would incorporate the idea of externals, I think it would cure quite a few people's complaints.