as discussed on IRC, the xslt-config and pkg-config module need to make sure the app links to libxml2 and finds its headers.
we also agreed that share/aclocal/libxslt.m4 ships. This all is to be seen in context with D34338.

Thanks for all the hard work!

Daniel, I think the port is broken the way it is. Either it enables the test configuration unconditionally (and without a TEST option), or else you need to make it conditional as suggested. It is common for ports that do not have support for tests to just silently pass a "make test" in that case (for instance, if TEST_TARGET is empty).

Much better for py-libxml2.

doesn't work when built as a port with Python 3.8 and 3.10 installed, something is being mixed up in the build. The intention is to build a Py38 based port, but the result is that Py310 seeps in.