---
upgrade:
  - |
    pyScss 1.3.7 is now required due to the incompatibility that
    pyScss 1.3.4 used before in horizon does not work with setuptools 46.
  - |
    Along with the upgrade of pyScss to 1.3.7, a workaround for the
    material design theme is added to make it work properly.
    See [:bug:`1771559`] for detail.
