sh-3.1$ git subtree pull -P LuaBridge luabridge master --squash
From github.com:vinniefalco/LuaBridge
 * branch            master     -> FETCH_HEAD
CONFLICT (rename/delete): LuaBridge/shared_ptr.h deleted in HEAD and renamed in 88bcdaa1127d45aa422e2deaeb2408533a5d0661. Version 88bcdaa1127d45aa422e2deaeb2408533a5d0661 of LuaBridge/shared_ptr.h left in tree.
Auto-merging LuaBridge/LuaBridge.h
CONFLICT (add/add): Merge conflict in LuaBridge/LuaBridge.h
Automatic merge failed; fix conflicts and then commit the result.
sh-3.1$git status

# On branch master
# Changes to be committed:
#
#       modified:   LuaBridge/README.md
#
# Unmerged paths:
#   (use "git add/rm <file>..." as appropriate to mark resolution)
#
#       both added:         LuaBridge/LuaBridge.h
#       added by them:      LuaBridge/shared_ptr.h
#