Gentoo's Bugzilla –
Attachment 910984 Details for
Bug 944289media-gfx/prusaslicer-2.9.0 fails to compile: test_emboss.cpp:908:90: error: class std::optional<CGAL::Surface_mesh<CGAL::Point_3<CGAL::Epick> >::Property_map<CGAL::SM_Face_index, int> > has no member named first