The function call in the documentation string https://github.com/JuliaSmoothOptimizers/KrylovPreconditioners.jl/blob/14ccb80a2fd193c1b4a3cd459850d6f274eb4b75/src/krylov_preconditioners.jl#L36 should read P = kp_ilu0(A) instead of P = kp_ic0(A)