Not sure why I am unable to get past this error... I am forcing the use of lxml2 2.13.16 but when I build it seems to be pulling (or assuming) that I am using a 2.12.x version of the library. Note that the 2.12.x comes from reading the "LIBXML_VERSION" attribute...

  version = PyObject_GetAttrString(lxml, "LIBXML_VERSION")

E xmlsec.Error: (100, 'lxml & xmlsec libxml2 library version mismatch')
=========================================================== short test summary info ============================================================
ERROR tests/test_constants.py - xmlsec.InternalError: (-1, 'lxml & xmlsec libxml2 library version mismatch')
ERROR tests/test_ds.py - xmlsec.Error: (100, 'lxml & xmlsec libxml2 library version mismatch')
ERROR tests/test_enc.py - xmlsec.Error: (100, 'lxml & xmlsec libxml2 library version mismatch')
ERROR tests/test_keys.py - xmlsec.Error: (100, 'lxml & xmlsec libxml2 library version mismatch')
ERROR tests/test_main.py - xmlsec.Error: (100, 'lxml & xmlsec libxml2 library version mismatch')
ERROR tests/test_pkcs11.py - xmlsec.Error: (100, 'lxml & xmlsec libxml2 library version mismatch')
ERROR tests/test_templates.py - xmlsec.Error: (100, 'lxml & xmlsec libxml2 library version mismatch')
ERROR tests/test_tree.py - xmlsec.Error: (100, 'lxml & xmlsec libxml2 library version mismatch')
ERROR tests/test_type_stubs.py - xmlsec.Error: (100, 'lxml & xmlsec libxml2 library version mismatch')
ERROR tests/test_xmlsec.py - xmlsec.Error: (100, 'lxml & xmlsec libxml2 library version mismatch')
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Interrupted: 10 errors during collection !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
============================================================== 10 errors in 0.62s ==============================================================

(this is debug output of printf("%ld %ld %ld %ld\n", PyLong_AsLong(major), PyXmlSec_GetLibXmlVersionMajor(), PyLong_AsLong(minor), PyXmlSec_GetLibXmlVersionMinor());):

2 2 12 13
2 2 12 13
2 2 12 13
2 2 12 13
2 2 12 13
2 2 12 13
2 2 12 13
2 2 12 13
2 2 12 13
2 2 12 13