> Using a git submodule for gtest is not an accepted solution for large projects.
Why not?
Because when you use git submodules, you run into issues like cloning without recursive flag, rebasing can be a pain, git diff shows unrelated changes which forces you to commit unnecessary things, switching branches with submodules is a pain et al.
If you are a individual developer, you can follow strict rules like dOing git submodule update and so on but when you are working with many collaborators enforcing this is a pain and most open source projects thus enforce no sub modules as a rule to prevent such things. I am not saying they are bad. They have a valid use case but calls for more discipline and the disadvantages far outweigh the advantages and hence I tend to favor package managers