the db initialisation (with roundup-admin initialise)
will fail if there is a lock on the db. That is, the
initialisation needs to delete the db, and if it
cannot, the initialisation will fail.  Fair enough. 

BUT, even though the db could not be deleted, the
backend_name file will be deleted. If you then release
the lock on db, and re-run the initialisation, now it
will fail in line 73 of instance.py in get_backend_name
complaining that there is no backend_name file.  

The workaround is:
1. create this file by hand (it contains only the name
of the backend (e.g. sqlite)
2. re-run the install (but then you'll lose your
config.ini changes).