fix: properly construct caches with non-concrete u0

Author: AayushSabharwal

src/problems/sccnonlinearproblem.jl

@@ -234,29 +234,30 @@ function SciMLBase.SCCNonlinearProblem{iip}(sys::System, op; eval_expression = f
         push!(nlfuns, f)
     end
 
+    u0_eltype = Union{}
+    for x in u0
+        symbolic_type(x) == NotSymbolic() || continue
+        u0_eltype = typeof(x)
+        break
+    end
+    if u0_eltype == Union{}
+        u0_eltype = Float64
+    end
+    u0_eltype = float(u0_eltype)
+
     if !isempty(cachetypes)
         templates = map(cachetypes, cachesizes) do T, n
             # Real refers to `eltype(u0)`
             if T == Real
-                T = eltype(u0)
+                T = u0_eltype
             elseif T <: Array && eltype(T) == Real
-                T = Array{eltype(u0), ndims(T)}
+                T = Array{u0_eltype, ndims(T)}
             end
             BufferTemplate(T, n)
         end
         p = rebuild_with_caches(p, templates...)
     end
 
-    u0_eltype = Union{}
-    for x in u0
-        symbolic_type(x) == NotSymbolic() || continue
-        u0_eltype = typeof(x)
-        break
-    end
-    if u0_eltype == Union{}
-        u0_eltype = Float64
-    end
-    u0_eltype = float(u0_eltype)
     subprobs = []
     for (i, (f, vscc)) in enumerate(zip(nlfuns, var_sccs))
         _u0 = SymbolicUtils.Code.create_array(