nekRS fails for genbox-generated mesh

[thorgjesdal]

We use meshes generated by genbox to simulate the axial flow between two concentric cylinders.
In genbox there are two primitives that can be used to generate this annular mesh, Circle and cYlinder.
The workflow for meshing is roughly:

1. generate 2D mesh with genbox
2. extruding to 3D mesh using n2to3

If we use the Circle primitive, we can compute the flow both using nek5000 and nekRS.
We would however like to extend the case to compute the flow along a cylinder in a square duct, and the cYlinder primitive offers more flexibility to do this.
This mesh runs fine in nek5000, whereas when we try to run nekRS it exits with the following message:

importing BCs from nek
Found unsupport BC type: ' '
ERROR: Invalid velocity boundary condition type! ierr= 1

It seems that the error is thrown at line 884-893 in src/nekInterface/nekInterface.f

Any ideas?