I am having a problem with a 2D Carpet unigrid simulation with NxNx1 grid points in each direction. I have 0 boundary points and 0 ghost points in the z direction. The norm2 and other norms computed by CarpetIOBasic and CarpetIOScalar are showing poison. The same happens if I use one boundary point and one ghost point. The important feature is that zmin = zmax. If I make zmax = zmin + dz, then the norms are fine. This works fine in the git version of Carpet - it seems to be a regression in the Mercurial version.
Parameter file is attached.