Snapcraft many changes?

Hello all.
I get errors when using snapcraft 3.0.1

For configflag in parts:

Failed to load plugin: properties failed to load for app: Additional properties are not allowed (‘configflags’ was unexpected)

and for - no-system-libraries in parts:

Issues while validating snapcraft.yaml: The ‘parts/app/build-attributes[1]’ property does not match the required schema: ‘no-system-libraries’ is not one of [‘no-patchelf’, ‘no-install’, ‘debug’, ‘keep-execstack’]

How I can build if I don’t need libs for system?
Thx.

I guess this is now the default of snapcraft 3.0.1?

Probably related:
https://github.com/snapcore/snapcraft/pull/2337

Yes, I use 3.0.1
Without this indication, my package contains have 2 version Qt libraries, and Qt versions what need for app.