GIT_REPOSITORY_OPEN_NO_SEARCH - Only open the repository if it can be
immediately found in the start_path. Do not walk up from the
start_path looking at parent directories.
GIT_REPOSITORY_OPEN_CROSS_FS - Unless this flag is set, open will not
continue searching across filesystem boundaries (i.e. when st_dev
changes from the stat system call). (E.g. Searching in a user's home
directory "/home/user/source/" will not return "/.git/" as the found
repo if "/" is a different filesystem than "/home".)
