Failure in eigs test with 3.1.54

[Rafael Laboissiere]

When building version 3.1.54-1 of the Debian package octave3.1, I noticed
that the eigs.cc tests failed.  I found a minimal code to reproduce the
error, in my Debian sid chroot:

$ octave3.1 -q
octave3.1:1> n = 20;
octave3.1:2> k = 4;
octave3.1:3> A = 
sparse([3:n,1:n,1:(n-2)],[1:(n-2),1:n,3:n],[ones(1,n-2),1:n,-ones(1,n-2)]);
octave3.1:4>  d0 = eig (A);
error: memory exhausted or requested size too large for range of Octave's
index type -- trying to return to prompt

Before I start trying to debug the above, could someone please tell me
whether this is an expected failure or not?

-- 
Rafael