Yesterday, ST released a new version of the board support for stm32 boards. There is currently a bug with the compatibility with DaisyDuino and this new update that breaks compilation.
We are going to work to get it patched ASAP (early next week at the latest).
However, in the meantime it is advised not to update to the new version (v2.0).
If you are a new user, or have already updated you should be able to use the following link in your preferences to access the now-deprecated earlier versions (<=v1.9):
DaisyDuino has been tested, and is compatible with v1.9