tests/sitecustomize.py

basectx: preserve loading the cached manifest in _prestatus

This is just a copy from localrepo.status and is a small step to removing that
method entirely. The prestatus hook is only called for changectx's, thereby
ensuring that the same behavior is guaranteed.

try:
    import coverage
    getattr(coverage, 'process_startup', lambda: None)()
except ImportError:
    pass