#FreeBSD port devel/appstream 1.1.2 (in ports tree git branch 2026Q2) failed with error messages the 'Net never saw:
FAILED: [code=1] data/org.freedesktop.appstream.cli.metainfo.xml
ImportError: /usr/local/lib/python3.11/site-packages/lxml/etree.cpython-311.so: Undefined symbol "xmlSchematronFree"
The only hint is Bug 292775:
Upgrade devel/py-lxml (from py311-lxml-6.0.1 to py311-lxml-6.0.4 in my case), which upgraded lang/cython (from py311-cython3-3.2.2 to py311-cython-3.2.4 in my case).
Bug 292775 is totally and completely unrelated, but it was one of only three hits when I broadened my search by deleting search terms until only this remained:
Undefined symbol "xmlSchematronFree"