focus change during evaluation

[Sascha Ziemann]

When I evaluate an slist with C-x C-e the "*Geiser Debug*" buffer
sometimes steals the focus. I have observed the following cases. If
the evaluation fails, because a symbol is undefined, the focus gets
stolen. And when the output of the evaluation is big, the focus gets
stolen, too. When the result of the evaluation is only small, the
focus is not stolen. The fact that the focus gets stolen sometimes is
a bit annoying.

How can I disable any focus change, when I press C-x C-e?