Comment 9 for bug 1960668

Yes, the above is the correct fix. Use a local source build to make sure that both xmlsec and lxml use the same version of libxml2.

    pip install --no-binary lxml lxml

Note that the Anaconda/condaforge/etc. packages should also come with matching libxml2 libraries and should thus work out of the box.

It's generally difficult to assure that different Python packages that depend on an external library get to use the same library version since Python packages cannot control the system libraries. And the large majority of all lxml installations benefits from a one-package-includes-all binary installation. Complicating that for making the life of xmlsec users easier would be the wrong trade-off (sorry).

I'm open for improvements, but I value the simplicity of millions of installations higher than that of thousands.