I found that in new dev_appserver dubugging is not possible and old_app_devserver need to be used.
As I found in previous version 1.7.x is because probable invalid use of stdin and stdout - what is changed in 1.8.x or still the same problem. PyDev Breakpoints in App Engine 1.7.6 broken?
What is other debug possibility options (IDEs) mean setting breakpoints not logging only.