  A four-dimensional supergravity toy model in an arbitrary self-dual
gravi-photon background is constructed in Euclidean space, by freezing out the
gravi-photon field strength in the standard N=(1,1) extended supergravity with
two non-chiral gravitini. Our model has local N=(1/2,0) supersymmetry.
Consistency of the model requires the background gravi-photon field strength to
be equal to the self-dual (bilinear) anti-chiral gravitino condensate.
