Drush make, git repository checkout specific subdirectory I've got a make file in which I want to pull in a remote Git repository and only fetch a subdirectory. I've tried as following: 

projects[example_module][type] = "module"
projects[example_module][download][type] = "git"
projects[example_module][download][url] = "git@bitbucket.org:team/example_modules.git"
projects[example_module][download][subtree] = "example_module_subdir"


Though, this creates a example_module folder where I expect it to be, though it contains the entire repository. What am I overlooking? Is this impossible? (using Drush 7.0.0)
The [subtree] only works if the download is an archive.
See Project download options page for drush 7.x.