deps/CMakeLists.txt only extracted CGAL when WITH_CGAL=ON. With -DWITH_CGAL_TESTS=ON the CGAL include path was never populated, causing fatal error: CGAL/Simple_cartesian.h: No such file or directory. Fix: extract CGAL-6.1.1 for both WITH_CGAL and WITH_CGAL_TESTS. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>