Hi,

libxml2 recently regressed its nopython build profile in two regards.
For one thing, it gained a python3-setuptools dependency that lacks a
<!nopython> annotation. This is not fatal, but an unused dependency.
What is fatal is that the __pycache__ is being cleaned up an that
absence of a __pycache__ makes the build fail. I'm attaching a patch for
your convenience.

Helmut