For example: $ dmd -H -o- atk/Action.d gio/DBusProxy.d -Hdinclude
Both files are written to the 'include' folder but they're flat because the original folder structure is lost. So instead of having: include/atk/Action.d include/gio/DBusProxy.d I have: include/Action.d include/DBusProxy.d The files are completely unusable this way (and this happens regardless of -Hd btw). I didn't find an open bug report on this, but I think this is worthy of an enhancement request.