Instead of just having predefined paths in the packagename-1.0.data/[path] directories, the user could define additional values for "path" in the {"path" : "installation directory"} dictionary used by wheel installers. (I'm not 100% sure this proposed feature does not cause more problems than it solves...)
well, as it is now, if "data_files" contains absolute paths, wheel silently produces broken whl packages. i.e. it produces packages that install your data_files relative to sys.prefix (not as absolute) so the proposed feature of custom paths, would at least offer a way to un-break those packages. another option for right now (and maybe in the long term too) though is to refuse to ever build wheels for these packages in the first place (see discussion in https://bitbucket.org/pypa/wheel/issue/92/bdist_wheel-makes-absolute-data_fi... )