zope: force module import by importing symbols...
zope: force module import by importing symbols
Previously, we tried to import a module and handle the ImportError.
Our lazy module importer doesn't verify the module exists and returns
a dummy object representing the module. Only once we attempt to load
a symbol in the module does the ImportError get raises.
This means that simple imports inside `try..except ImportError` don't
detect missing modules.
This commit changes imports in zope.interface to access symbols, thus
forcing module load and triggering ImportError.
This fixes zope.interface for pure builds.
Differential Revision:
https://phab.mercurial-scm.org/D2980
