Found the following significant warnings:
  ../inst/include/s2/util/gtl/btree.h:604:22: warning: array subscript [33, 287] is outside array bounds of ‘absl::container_internal::Allocate<8, std::allocator<int> >(std::allocator<int>*, size_t)::M [32]’ [-Warray-bounds]
  ../inst/include/s2/util/gtl/btree.h:597:58: warning: array subscript [32, 287] is outside array bounds of ‘absl::container_internal::Allocate<8, std::allocator<int> >(std::allocator<int>*, size_t)::M [32]’ [-Warray-bounds]
  ../inst/include/s2/util/gtl/btree.h:604:22: warning: array subscript [33, 287] is outside array bounds of ‘absl::container_internal::Allocate<8, std::allocator<S2ClosestEdgeQueryBase<S2MinDistance>::Result> >(std::allocator<S2ClosestEdgeQueryBase<S2MinDistance>::Result>*, size_t)::M [32]’ [-Warray-bounds]
  ../inst/include/s2/util/gtl/btree.h:597:58: warning: array subscript [32, 287] is outside array bounds of ‘absl::container_internal::Allocate<8, std::allocator<S2ClosestEdgeQueryBase<S2MinDistance>::Result> >(std::allocator<S2ClosestEdgeQueryBase<S2MinDistance>::Result>*, size_t)::M [32]’ [-Warray-bounds]
  ../inst/include/s2/util/gtl/btree.h:604:22: warning: array subscript [33, 287] is outside array bounds of ‘absl::container_internal::Allocate<8, std::allocator<std::pair<const int, int> > >(std::allocator<std::pair<const int, int> >*, size_t)::M [32]’ [-Warray-bounds]
  ../inst/include/s2/util/gtl/btree.h:597:58: warning: array subscript [32, 287] is outside array bounds of ‘absl::container_internal::Allocate<8, std::allocator<std::pair<const int, int> > >(std::allocator<std::pair<const int, int> >*, size_t)::M [32]’ [-Warray-bounds]
  ../inst/include/s2/util/gtl/btree.h:604:22: warning: array subscript [31, 285] is outside array bounds of ‘absl::container_internal::Allocate<8, std::allocator<std::pair<const Vector3<double>, int> > >(std::allocator<std::pair<const Vector3<double>, int> >*, size_t)::M [30]’ [-Warray-bounds]
  ../inst/include/s2/util/gtl/btree.h:597:58: warning: array subscript [30, 285] is outside array bounds of ‘absl::container_internal::Allocate<8, std::allocator<std::pair<const Vector3<double>, int> > >(std::allocator<std::pair<const Vector3<double>, int> >*, size_t)::M [30]’ [-Warray-bounds]
  ../inst/include/s2/util/gtl/btree.h:604:22: warning: array subscript [33, 287] is outside array bounds of ‘absl::container_internal::Allocate<8, std::allocator<std::pair<S2Loop* const, std::pair<int, bool> > > >(std::allocator<std::pair<S2Loop* const, std::pair<int, bool> > >*, size_t)::M [32]’ [-Warray-bounds]
  ../inst/include/s2/util/gtl/btree.h:597:58: warning: array subscript [32, 287] is outside array bounds of ‘absl::container_internal::Allocate<8, std::allocator<std::pair<S2Loop* const, std::pair<int, bool> > > >(std::allocator<std::pair<S2Loop* const, std::pair<int, bool> > >*, size_t)::M [32]’ [-Warray-bounds]
  ../inst/include/s2/util/gtl/btree.h:604:22: warning: array subscript [33, 287] is outside array bounds of ‘absl::container_internal::Allocate<8, std::allocator<S2ClosestEdgeQueryBase<S2MaxDistance>::Result> >(std::allocator<S2ClosestEdgeQueryBase<S2MaxDistance>::Result>*, size_t)::M [32]’ [-Warray-bounds]
  ../inst/include/s2/util/gtl/btree.h:597:58: warning: array subscript [32, 287] is outside array bounds of ‘absl::container_internal::Allocate<8, std::allocator<S2ClosestEdgeQueryBase<S2MaxDistance>::Result> >(std::allocator<S2ClosestEdgeQueryBase<S2MaxDistance>::Result>*, size_t)::M [32]’ [-Warray-bounds]
See ‘/home/hornik/tmp/R.check/r-devel-gcc/Work/PKGS/s2.Rcheck/00install.out’ for details.