make tests pass

Author: oscardssmith

lib/OrdinaryDiffEqDifferentiation/src/derivative_utils.jl

@@ -883,7 +883,7 @@ function build_J_W(alg, u, uprev, p, t, dt, f::F, ::Type{uEltypeNoUnits},
         # Thus setup JacVec and a concrete J, using sparsity when possible
         _f = islin ? (isode ? f.f : f.f1.f) : f
         J = if f.jac_prototype === nothing
-            ArrayInterface.undefmatrix(u)
+            ArrayInterface.zeromatrix(u)
         else
             deepcopy(f.jac_prototype)
         end
@@ -907,10 +907,11 @@ function build_J_W(alg, u, uprev, p, t, dt, f::F, ::Type{uEltypeNoUnits},
                 f.jac(uprev, p, t)
             end
         elseif f.jac_prototype === nothing
-            ArrayInterface.undefmatrix(u)
+            ArrayInterface.zeromatrix(u)
         else
             deepcopy(f.jac_prototype)
         end
+        
         W = if alg isa DAEAlgorithm
             J
         elseif IIP
@@ -1003,4 +1004,4 @@ function resize_J_W!(cache, integrator, i)
     end
 
     nothing
-end
+end

lib/OrdinaryDiffEqDifferentiation/src/linsolve_utils.jl

@@ -39,7 +39,7 @@ end
 
 function wrapprecs(linsolver, W, weight)
     if isnothing(linsolver)
-        linsolver = LinearSolve.defaultalg(W, weight, LinearSolve.OperatorAssumptions(true))
+        linsolver = LinearSolve.LUFactorization()
     end
     if hasproperty(linsolver, :precs) && isnothing(linsolver.precs)
         Pl = LinearSolve.InvPreconditioner(Diagonal(_vec(weight)))