installPackage doesn't do anything, without loading the OFS configure.zcml...

installPackage doesn't do anything, without loading the OFS configure.zcml first. The ZopeLite layer doesn't know anything about ZCML, so we rather defer the setup to consumers.

doc/CHANGES.rst

@@ -25,7 +25,10 @@ Restructuring
 - No longer use HelpSys pages from ``Products.OFSP`` in core Zope 2.
 
 - Register OFS as a package and give it an initialize function. Moved
-  registration of OFS classes there from Products.OFSP.
+  registration of OFS classes there from Products.OFSP. ZopeTestCase will no
+  longer install the OFSP product automatically, so you might need to change
+  your test layer setup to load the OFS configure.zcml and call
+  installPackage('OFS').
 
 - No longer create an `Extensions` folder in the standard instance skeleton.
   External methods will become entirely optional in Zope 2.14.

src/Testing/ZopeTestCase/ZopeLite.py

@@ -218,7 +218,6 @@ def _installPackage(name, quiet=0):
             if not quiet: _print('Installing %s ... NOT FOUND\n' % name)
 
 installProduct('PluginIndexes', 1)  # Must install first
-installPackage('OFS', 1)
 
 # So people can use ZopeLite.app()
 app = Zope2.app