  We describe a conceptually simple, but important test for the overlap
approach to the construction of lattice chiral gauge theories. We explain the
equivalence of the overlap formula with a certain waveguide model for a simple
set of gauge configurations (the trivial orbit). This equivalence is helpful in
carrying out the test, and casts serious doubts on the viability of the overlap
approach. A recent note by Narayanan and Neuberger which points out a mistake
in our previous work is irrelevant in this context.
