Hack for logging a deprecation warning when a deprecated route is visited.

deprecated-routes.py

# ...

import logging
log = logging.getLogger(__name__)

def warn_deprecated(environ, result):
    log.warn("Deprecated route used: %s" % environ['PATH_INFO'])
    return True

def make_map(config):
    # ...

    map.connect('/my-deprecated-route/foo', controller='foo', action='bar',
                conditions=dict(function=warn_deprecated))