Debugging - Show error on page or terminal or log

[joseluizcoe]

When i'm doing something wrong, grow.io show me one blank page and don't give me any information about the error. How can i debug to know what am i doing wrong?

This console message don't tell me where is the error in my code:

WSGI application error Traceback (most recent call last): File "/Users/joseluizcoe/myapp/lib/python2.7/site-packages/twisted/python/threadpool.py", line 262, in inContext.theWork = lambda: context.call(ctx, func, _args, _kw) File "/Users/joseluizcoe/myapp/lib/python2.7/site-packages/twisted/python/context.py", line 118, in callWithContext return self.currentContext().callWithContext(ctx, func, _args, _kw) File "/Users/joseluizcoe/myapp/lib/python2.7/site-packages/twisted/python/context.py", line 83, in callWithContext self.contexts.pop() File "/Users/joseluizcoe/myapp/lib/python2.7/site-packages/twisted/web/wsgi.py", line 521, in run self.started = True --- --- File "/Users/joseluizcoe/myapp/lib/python2.7/site-packages/twisted/web/wsgi.py", line 496, in run appIterator = self.application(self.environ, self.startResponse) File "/Users/joseluizcoe/myapp/lib/python2.7/site-packages/werkzeug/wsgi.py", line 579, in call return self.app(environ, start_response) File "/Users/joseluizcoe/myapp/lib/python2.7/site-packages/grow/server/main.py", line 97, in call return self.wsgi_app(environ, start_response) File "/Users/joseluizcoe/myapp/lib/python2.7/site-packages/grow/server/main.py", line 93, in wsgi_app response = self.dispatch_request(request) File "/Users/joseluizcoe/myapp/lib/python2.7/site-packages/grow/server/main.py", line 89, in dispatch_request return self.handle_exception(request, e) File "/Users/joseluizcoe/myapp/lib/python2.7/site-packages/grow/server/main.py", line 101, in handle_exception if isinstance(exc, webob.exc.HTTPException): exceptions.AttributeError: 'module' object has no attribute 'exc'

How can i debug my code?