Currently when dsss calls rebuild, it puts DSSS's include and lib dirs first, before user-specified include and lib directories. This means you always get the installed versions of files even if you explicitly give a different directory to use in your dsss.conf or on the command line.
That means you have no way to override the dsss versions besides to uninstall the dsss versions. But maybe in another project you're relying on the installed versions in most of your projects.
Installed files should never take precedence over files in the include and lib directories manually specified by the user.