Activating the Flask debugger when running under mod_wsgi
As described in the Flask documentation at:
http://flask.pocoo.org/docs/quickstart/#debug-mode
use:
app.debug = True
Under mod_wsgi you aren't doing the app.run() though.
Ensure you are setting 'app.debug' at global scope and not in a conditional section where checking whether __name__ is __main__.
You may use interactive debugger provided by werkzeug:
from werkzeug.debug import DebuggedApplication
application = DebuggedApplication(app, True)
This is earley suggested by @jd work for me.