Handling non-parsed flags

[mwriter]

I need to make that all non-parsed flags are treated as Args.
If run it as
someCmd --knownFlag --unknownFlag
then
Incorrect Usage: flag provided but not defined: --unknownFlag
But if run it as
someCmd --defFlag -- --unknownFlag
then it works as it should.
However, I would like to avoid using --.
The option SkipFlagParsing cancels all automatic parsing altogether, and this isn't a solution.

[mwriter]

It looks like I'm not the first one with this issue
#2109
Moreover, there is no such thing in cobra. There is some kind of failure in the seemingly simplest issue, even python has a default implementation.