  We consider the Euler system of gas dynamics endowed with the incomplete
equation of state relating the internal energy to the mass density and the
pressure. We show that any sufficiently smooth solution can be recovered as a
vanishing viscosity - heat conductivity limit of the Navier--Stokes--Fourier
system with a properly defined temperature. The result is unconditional in the
case of the Navier type (slip) boundary conditions and extends to the no-slip
condition for the velocity under some extra hypotheses of Kato's type
concerning the behavior of the fluid in the boundary layer.
