Python crashes on Mac OS X
Dexterity indirectly depends on lxml, due to a dependency of z3c.relationfield.
If you are on Mac OS X, you may fall victim to an incompatibility between recent versions of lxml and the versions of libxml2 and libxslt that come installed with Mac OS X. This causes a segmentation fault when certain lxml commands are run, typically manifesting a Python crash (and a dialog box to that effect) when Plone starts up.
Read more about this here.
