Cannot load /opt/apache/libexec/libdav.so into server: /opt/apache/libexec/libdav.so: undefined symbol: XML_SetElementHandler

This always gets me… For some reason, mod_dav doesn’t find expat on Debian. The fix is:

./configure –with-apxs=/opt/apache/bin/apxs –with-expat=/usr

make

make install