There are many things about git submodules that are more unpleasant than they should be but one of the most frustrating is that you have to decide early whether to add the submodules as git+ssh URLs or https urls. If you pick ssh URLs, your Windows users using GUIs will not be able to check out the submodules. Whereas if you pick https URLs, your Mac and Linux users using the command line will not be able to check out the submodules. Once you have picked one of these choices, you can't change it
