Fix another issue

Author: Katharine Hyatt

test/testsuite/mooncake.jl

@@ -77,7 +77,13 @@ function _get_copying_derivative(f, rrule, A, ΔA, args, Δargs, ::Nothing, rdat
     else
         copyto!(Mooncake.tangent(copy_out), dargs_copy)
     end
-    @test Mooncake.primal(copy_out) ≈ args
+    if args isa Tuple
+        for (arg, out) in zip(args, Mooncake.primal(copy_out))
+            @test out ≈ arg
+        end
+    else
+        @test Mooncake.primal(copy_out) ≈ args
+    end
     copy_pb!!(rdata)
     return dA_copy, Mooncake.tangent(copy_out)
 end