6.3 set_cookie() got an unexpected keyword argument 'HttpOnly'

[eljeffeg]

Getting this issue changing from Tornado 6.2 -> 6.3

rtb-webapp-1     | [E 230418 15:28:08 BaseHandlers:195] Request from x.x.x.x resulted in an error code 500:
rtb-webapp-1     |     Traceback (most recent call last):
rtb-webapp-1     |       File "/usr/local/lib/python3.8/site-packages/tornado/web.py", line 1767, in _execute
rtb-webapp-1     |         result = method(*self.path_args, **self.path_kwargs)
rtb-webapp-1     |       File "/opt/rtb/libs/SecurityDecorators.py", line 106, in wrapper
rtb-webapp-1     |         return method(self, *args, **kwargs)
rtb-webapp-1     |       File "/opt/rtb/handlers/PublicHandlers.py", line 224, in post
rtb-webapp-1     |         self.valid_login(user)
rtb-webapp-1     |       File "/opt/rtb/handlers/PublicHandlers.py", line 276, in valid_login
rtb-webapp-1     |         self.successful_login(user)
rtb-webapp-1     |       File "/opt/rtb/handlers/PublicHandlers.py", line 291, in successful_login
rtb-webapp-1     |         self.start_session()
rtb-webapp-1     |       File "/opt/rtb/handlers/BaseHandlers.py", line 102, in start_session
rtb-webapp-1     |         self.set_secure_cookie("session_id", self.session.session_id, **flags)
rtb-webapp-1     |       File "/usr/local/lib/python3.8/site-packages/tornado/web.py", line 756, in set_signed_cookie
rtb-webapp-1     |         self.set_cookie(
rtb-webapp-1     |     TypeError: set_cookie() got an unexpected keyword argument 'HttpOnly'

[bdarnell]

Oops, looks like the http.cookies module has some case-insensitive magic that I missed. I'll get this fixed, but in the meantime you can work around it by changing to lowercase httponly (it looks like **flags in your code contains HttpOnly).

[bdarnell]

This is fixed in Tornado 6.3.1, which was just released.