NekMesh fails to extract a boundary of a simple curved cylindrical shape. extracting the wall and one inlet works ``` NekMesh -m extract:surf=3 siphon_taper_spherigon.xml siphon_taper_spherigon_3.xml NekMesh -m extract:surf=2 siphon_taper_spherigon.xml siphon_taper_spherigon_2.xml ``` but fails on ``` NekMesh -m extract:surf=4 siphon_taper_spherigon.xml siphon_taper_spherigon_4.xml Segmentation fault (core dumped) ``` [siphon_taper_spherigon.xml](/uploads/0cbf8a6a263730f859626dcd05c50197/siphon_taper_spherigon.xml)