wrapFunctionCalls failed for sum

[Vitalij Ruge]

following example failed

function foo
  input Real[:] x;
  output Real[:] y = x;
end foo;

model foobar
  Real y = sum(foo({time, time*2}));
equation
end foobar;

with
Error: post-optimization module wrapFunctionCalls (simulation) failed.

[Lennart Ochel]

Why does the cse module fail for sum?

[Vitalij Ruge]

Replying to lochel:

Why does the cse module fail for sum?

I added lochel as CC.
He's been working on cse and can probably explain better than me.

[Lennart Ochel]

Vitalij, I asked the question. So could you please explain why the cse module failed and why it is a good idea to skip function sum?