This library is great I have used it for some things that would have been near impossible in openscad without it! In fact it is keeping me using openscad when I might otherwise have given up.
However I just noticed a problem, the latest version(s?) of CGAL refuse to render objects made with extrude along path, and returns the following error:
ERROR: CGAL error in CGAL_Nef_polyhedron3(): CGAL ERROR: assertion violation! Expr: ss_circle.has_on(sp) File: /usr/include/CGAL/Nef_3/polygon_mesh_to_nef_3.h Line: 263
So running an installed version of openscad on Fedora 27, or the latest appimage from the openscad website, causes the problem, but setups with an older version of CGAL, such as the appimage from 2017.03.02 which I have, or an installed version running on Fedora 25 are fine.
Anyway I am hoping you might be able to find a workaround in your code, or, if appropriate, file a bug report with CGAL, I don't have the expertise to do either!