... shouldn't give any problems for websites that already had old versions installed (like 1.0a6), because plone.app.stagingbehavior.interfaces.IStagingSupport (or any other additional behavior) would already be at cover portal_types definition.
Problem is that you have an upgradeStep that calls typeinfo again, so the behaviors in collective.cover overrides what we already had in ZODB. If you decide to call typeinfo again in the future, it would be safer to use purge="false".
Just removing plone.app.stagingbehavior in collective.cover:
https://github.com/collective/collective.cover/commit/651cf0b86b45f9398dabc108a14d5c49f79367bf https://github.com/collective/collective.cover/commit/3c5b9da7ca9330414f30400e54cbe432e2175834
... shouldn't give any problems for websites that already had old versions installed (like 1.0a6), because plone.app.stagingbehavior.interfaces.IStagingSupport (or any other additional behavior) would already be at cover portal_types definition.
Problem is that you have an upgradeStep that calls
typeinfo
again, so the behaviors in collective.cover overrides what we already had in ZODB. If you decide to calltypeinfo
again in the future, it would be safer to use purge="false".