The get_components target of the top-level makefile relies on a variable
SDK_PATH to know where to install the target components. This variable comes
from Rules.mak, but defaults to using C6RUN_INSTALL_DIR which has not yet been
defined when performing the get_components step on a clean download.
Will add code to the makefile to detect this case and use current working
directory as the SDK_PATH (which is equivalent to the previous behavior of
assuming that the local working directory (assumed to be the actual C6RUN
directory) was to hold the downloaded components).